Asthma and Plant-Based Diets

Asthma is a respiratory condition characterised by spasms in the bronchi of the lungs, resulting in breathing difficulties. It’s normally associated with allergic reactions or other forms of hypersensitivity. This blog will take a brief look at some evidence that suggests a central role for plant-based diets in the treatment of asthma and the prevention of asthmatic attacks.

Healthy body weight and asthma

  • two 2013 studies on asthma in children found that being overweight increases the risk of developing asthma by 35%, while being obese as a child increases the risk by 50% 1 and losing excess weight in children improves lung function2
  • this was further supported by a 2018 study: ““There are few preventable risk factors to reduce the incidence of asthma but our data show that reducing the onset of childhood obesity could significantly lower the public health burden of asthma.” 3

Fatty acid intake and asthma

Omega-6 fatty acids are mostly found in animal products. They are also found in margarines and other vegetable oils. The specific amounts of oil-based fats are shown in the chart below 4 . N.B. Consuming any form of oil or fat that’s been separated from its original food source is not to be advised, for reasons covered in previous blogs. 5 6 7 .

  • arachidonic acid (a long-chain omega-6 fatty acid) is found mainly in animal foods and has been shown to be a precursor of leukotrienes which have bronchoconstrictive effects 8 . Leukotrienes are a form of pro-inflammatory molecule released by mast cells during asthma attacks 9
  • omega-3 fatty acids, on the other hand, have been shown 10 to have anti-inflammatory effects
  • a higher ratio of omega-6 to omega-3 fatty acids in the diets of children has been shown 10 to have a significant association with an increased risk of asthma
  • omega-6 fatty acids have been shown 11 to hinder the incorporation of omega-3 fatty acids into tissue lipids and plasma
  • while some studies suggest 12 that fish-based omega-3 intake improves asthma symptoms in children, there are other studies 13 which contradict this and also suggest that such benefits in adults have not been proven
  • there are persuasive reasons for getting your omega-3 from walnuts, flaxseeds/chia seeds and/or plant-based omega-3 supplements rather than eating fish or using fish oil supplements 14 15

Saturated fat and asthma

  • evidence suggests 16 that when asthmatics eat diets containing high levels of total and saturated fat, there is an increase in the expression of those genes involved in airway inflammation
  • a 2010 study concluded 17 that high fat diets are able to inhibit the asthmatic’s response to the asthma medication Ventolin (albuterol)

Dairy products and asthma

  • a study 18 showed that pregnant women consuming low-fat yogurt once or more a day or low-fat milk 5.5 times or more a week had a 21% and 8% higher risk, respectively, for having a baby which would be diagnosed with asthma, as compared with women consuming no dairy
  • a 2015 study 19 found roughly 50% greater asthma prevalence in children who consumed butter 3 or more times a week, compared with those who either never consumed butter or only consumed it occasionally

Fast food and asthma

  • a 2013 study 20 found a ~40% increased risk of severe asthma developing in children and adolescents who consumed fast food 3 or more times a week, as compared with those who either never ate fast food or ate it only occasionally

Nuts, seeds and asthma

  • although tree nuts and peanuts can be allergenic to some people, a 2012 Danish study 21 found that nut intake during pregnancy was actually inversely related to an asthma diagnosis in their offspring at 18 months of age
  • a 2009 French study 22 looked at the risk that French women have of frequent asthma attacks (1 or more per week), and found that the risk was lower in women who consumed the highest amount of nuts and seeds (>5.3 g/day) when compared with those with the lowest consumption (≤ 1.0 g/day)

Salt and asthma

  • whilst there is evidence 23 that consuming a low-sodium (salt) diet appears to reduce bronchoconstriction in asthmatics in response to exercise, there is no strong evidence that a low-sodium diet (of itself) reduces the prevalence or severity of asthma 24
  • considering that salt is known 25  to be pro-inflammatory, it makes sense that it’s wise to avoid adding salt to your food and, of course, avoiding procesed foods which are known to be high in salt
  • a 2014 study concluded: “…our findings suggest that higher sodium consumption is associated with greater adiposity, leptin resistance, and inflammation independent of total energy intake and sugar-sweetened soft drink consumption.” 26

Fruits, vegetables and asthma

  • fruits, vegetables and other foods high in antioxidants have been shown 27 to produce ~45% lower risk for asthma in those children and adults who consume the most amount of fruits and vegetables, as compared with those who eat the least amount
  • a 2013 study 28 found that individuals who ate the lowest amount of fruit and vegetable (3 servings/day – typical of Western diets) had more than 50% increased risk of asthma exacerbation than those who ate 7 daily servings of fruits and vegetables
  • the European Academy of Allergy and Clinical Immunology (EAACI) recommended that clinical advice should be to increase the net intake of fruits and vegetables as a way of reducing the risk of asthma, particularly in children 29
  • a 2017 study concluded “higher intakes of fruits and vegetables may have a positive impact on asthma risk and asthma control.” 30 and provided an interesting schematic that compared the airway effects of the Western diet and a diet high in fruit and veg:

Vegetarian, vegan diets and asthma

  • a 1994 study 31 of almost 28,000 Seventh-day Adventists found that vegetarian women amongst the group reported a lower incidence of asthma, as compared to women who ate omnivore diets. “The theoretical basis for the value of vegan diets is the absence of potential triggers, particularly dairy products and eggs, as well as a relative lack of arachidonic acid.” 32
  • although the so-called Mediterranean diet is something of an anathema these days – with the spread of the modern Western diet across the continent – a 2014 review 33 found 7 out of 10 studies noted that there was a protective effect of a Mediterranean diet on the incidence of child asthma
  • a 1985 study used a vegan diet for 1 year as an alternative therapy to typical asthma drugs for a group of 35 asthma patients. They found a significant decrease in asthma symptoms as a result of this simple dietary intervention: “…71% reported improvement at 4 months and 92% at 1 yr. There was a significant improvement in a number of clinical variables; for example, vital capacity, forced expiratory volume at one sec and physical working capacity, as well as a significant change in various biochemical indices as haptoglobin, IgM, IgE, cholesterol, and triglycerides in blood. Selected patients, with a fear of side-effects of medication, who are interested in alternative health care, might get well and replace conventional medication with this regimen.” 34

Sugar-sweetened beverages and asthma

  • a 2009 US study 35 found an increased risk of developing asthma in those students who drank soda (fizzy drinks): 2 regular sodas a day meant a 28% increased risk, while 3 or more regular sodas a day meant a 64% increased risk. It was also pointed out that previous studies found asthma symptoms were worsened by regular soda consumption
  • a follow-up study 36 on non-obese adults found that those who consumed 2 or more sugar-sweetened beverages a day had ~65% increased risk of developing asthma, as compared to those who didn’t consume any such beverages
  • and it’s not just sodas that are the problem – a further 2016 US study 37 found that asthma risk in children between 2 and 9 years of age was significantly higher when they consumed apple juice or high fructose corn syrup-sweetened beverages 5 or more times a week, as compared to consuming only 1 or no such beverages per month

Alcohol and asthma

  • a 2012 study 38 found a U-shaped association between alcohol consumption and the development of new onset asthma in adults – that is, moderate weekly intake (1-6 units/week) showed a reduced risk, whilst those who never/rarely drank (<1 unit/month) and heavy drinkers (≥4 units/day) showed an increased risk. The risk of new-onset asthma was also shown to be lower for subjects with wine preference when compared with beer preference. However, the study authors admit that their findings were not statistically significant
  • contradictory information is provided by other authorities, including Asthma UK 39 , which claims that alcohol does exacerbate asthma symptoms, and a study in The Journal of Allergy and Clinical Immunology 40 , which states that wines are the greatest triggers for asthma attacks
  • whilst there’s obviously disagreement on this subject, and thus further research would be useful, previous blogs 41 42 have explained the reasons why any amount of alcohol intake has been shown to be potentially harmful

Vitamin D status and asthma

  • a 2014 meta-analysis 43 found that increased vitamin D deficiency was associated both with an increase in the incidence of asthma in general and with a decrease in lung function in asthmatic children in particular
  • whilst there is some disagreement on the benefits of vitamin D supplementation as a means of treating/preventing asthma in children 44 , an additional study 45 reported that those children who took vitamin D supplements reduced their risk of asthma by ~25%, as compared with children without supplemental vitamin D

Breastfeeding and asthma

  • a 2004 study 46 on the therapeutic measures for preventing the development of both allergic rhinitis and asthma, made the following suggestions for decreasing the the risk for developing asthma in babies during breastfeeding:
    • ensure that babies are breastfed for the first 4-6 months of life
    • avoid dairy products until at least 1 year old
    • avoid eggs until at least 2 years old
    • avoid nuts and fish until at least 3 years old

Inhalers and asthma

An interesting article appeared in The Telegraph today 47 entitled “Asthma inhalers as bad for the environment as 180-mile car journey, health chiefs say.” It points out the dangers to the environment of the hydrofluorocarbons (a powerful greenhouse gas) contained in the majority of the asthma inhalers (known as metered dose inhalers of MDI’s) used in the UK.

  • Nice (The National Institute for Health and Care Excellence) was reported to have calculated that “…five doses from an MDI have the same carbon emissions as a nine-mile trip in a typical car. The devices usually contain 100 doses. By contrast, dry powder inhalers are only around one fifth as bad for the environment.”
  • more than 5.4 million people in the UK receive treatment for asthma, including 1.1 million children
  • Britain has some of the highest rates in Europe, with around three people a day dying as a result of the condition

Whilst inhalers do, of course, save lives and users should only consider making changes in consultation with their doctor, they are known 48 to have side effects. Making dietary changes that help to prevent and treat asthma does seem to be a much better alternative, especially since the only side effects appear to be positive ones.

Final thoughts

The foregoing appears to suggest that there is, indeed, an important role for plant-based diets in the prevention and treatment of asthma. Such diets (so long as they are based on wholefood plants and avoid processed plant foods) are excellent for the maintenance of healthy weight and can provide the ideal fatty acid profile.

It’s clear that some particular foods are best avoided completely, including dairy products, fast food, sugar-sweetened beverages and, arguably, excessive amounts of salt – especially when contained in processed foods.

If you suffer from asthma, perhaps a useful way to check whether this dietary approach will alleviate your asthma is to stick with your current diet for a specific time, but keep a detailed daily record of asthma symptoms. After this, change to a non-SOS WFPB (no added sugar, salt or oil wholefood plant-based diet) for a similar specific period of time and maintain the daily diary. You would then be able to compare the frequency and intensity of symptoms between the two periods.

Should you decide to do this, and would like to share the results, please feel free to write to me with your findings and I will aim to publish them in a subsequent blog.

References & Notes

  1. Egan KB, Ettinger AS, Bracken MB: Childhood body mass index and subsequent physician-diagnosed asthma: a systematic review and meta-analysis of prospective cohort studies. BMC Pediatr 13:, 2013 []
  2. Moreira A et al: Weight loss interventions in asthma: EAACI evidence-based clinical practice guideline (part I). Allergy 68:425, 2013 []
  3. Obesity is linked to increased asthma risk in children, finds study BMJ 2018; 363 doi: 26 November 2018. []
  4. Comparison of Dietary Fats Chart []
  5. Surely Coconut Oil’s better than Butter?! []
  6. Olive Oil Injures Endothelial Cells []
  7. Coconut Oil is ‘Pure Poison’ says Harvard Professor []
  8. Pharmacotherapy. 1997 Jan-Feb;17(1 Pt 2):3S-12S. Arachidonic acid metabolites: mediators of inflammation in asthma. Wenzel SE []
  9. What are leukotrienes and how do they work in asthma? BMJ 1999; 319 doi: BMJ 1999;319:90 []
  10. Wendell SG, Baffi C, Holguin F: Fatty acids, inflammation, and asthma. J Allergy Clin Immunol 133:1255, 2014 [] []
  11. Dias CB, Wood LG, Garg ML: Effects of dietary saturated and n-6 polyunsaturated fatty acids on the incorporation of long-chain n-3 polyunsaturated fatty acids into blood lipids. Eur J Clin Nutr 70:812, 2016 []
  12. Pediatr Allergy Immunol. 2018 Jun;294:350-360. doi: 10.1111/pai.12889. The role of fish intake on asthma in children: A meta-analysis of observational studies. Papamichael MM, Shrestha SK, Itsiopoulos C, Erbas B. []
  13. Brannan JD et al: The effect of omega-3 fatty acids on bronchial hyperresponsiveness, sputum eosinophilia, and mast cell mediators in asthma. Chest 147:397, 2015 []
  14. Omega 3 Supplements = Snake Oil []
  15. Nutritionfacts: Omega-3 Fatty Acids []
  16. Li Q et al: Changes in Expression of Genes Regulating Airway Inflammation Following a High-Fat Mixed Meal in Asthmatics. Nutrients 8:, 2016 []
  17. American Thoracic Society. “High-fat meals a no-no for asthma patients, researchers find.” ScienceDaily. ScienceDaily, 17 May 2010. []
  18. Maslova E et al: Low-fat yoghurt intake in pregnancy associated with increased child asthma and allergic rhinitis risk: a prospective cohort study. J Nutr Sci Jul 06 []
  19. Saadeh D et al: Prevalence and association of asthma and allergic sensitization with dietary factors in schoolchildren: data from the french six cities study. BMC Public Health 15:, 2015 []
  20. Ellwood P et al: Do fast foods cause asthma, rhinoconjunctivitis and eczema? Global findings from the International Study of Asthma and Allergies in Childhood (ISAAC) phase three. Thorax 68:351, 2013 []
  21. Maslova E et al: Peanut and tree nut consumption during pregnancy and allergic disease in children-should mothers decrease their intake? Longitudinal evidence from the Danish National Birth Cohort. J Allergy Clin Immunol 130:724, 2012 []
  22. Varraso R et al: Dietary patterns and asthma in the E3N study. Eur Respir J 33:33, 2009 []
  23. Mickleborough TD: Salt intake, asthma, and exercise-induced bronchoconstriction: a review. Phys Sportsmed 38:118, 2010 []
  24. Cochrane Database Syst Rev. 2004;(3):CD000436. Dietary salt reduction or exclusion for allergic asthma. Ardern KD. []
  25. Eur J Clin Nutr. 2012 Nov;66(11):1214-8. doi: 10.1038/ejcn.2012.110. Epub 2012 Aug 22. Dietary salt intake is related to inflammation and albuminuria in primary hypertensive patients. Yilmaz R, Akoglu H, Altun B, Yildirim T, Arici M, Erdem Y. []
  26. Pediatrics. 2014 Mar; 133(3): e635–e642. Dietary Sodium, Adiposity, and Inflammation in Healthy Adolescents. Haidong Zhu et al. []
  27. Seyedrezazadeh E et al: Fruit and vegetable intake and risk of wheezing and asthma: a systematic review and meta-analysis. Nutr Rev 72:411, 2014 []
  28. Grieger JA, Wood LG, Clifton VL: Improving asthma during pregnancy with dietary antioxidants: the current evidence. Nutrients 5:3212, 2013. []
  29. Asthma and dietary intake: an overview of systematic reviews. Garcia-Larsen V, Del Giacco SR, Moreira A, Bonini M, Charles D, Reeves T, Carlsen KH, Haahtela T, Bonini S, Fonseca J, Agache I, Papadopoulos NG, Delgado L. Allergy. 2016 Apr; 71(4):433-42. []
  30. Nutrients. 2017 Nov; 9(11): 1227. Published online 2017 Nov 8. doi: 10.3390/nu9111227. Diet and Asthma: Is It Time to Adapt Our Message? Laurent Guilleminault et al. []
  31. Knutsen SF: Lifestyle and the use of health services. Am J Clin Nutr 59:1171S, 1994. []
  32. PCRM: Nutrition Guide for Clinicians: Asthma. []
  33. Lv N, Xiao L, Ma J: Dietary pattern and asthma: a systematic review and meta-analysis. J Asthma Allergy 7:105, 2014 []
  34. J Asthma. 1985;22(1):45-55. Vegan regimen with reduced medication in the treatment of bronchial asthma. Lindahl O, Lindwall L, Spångberg A, Stenram A, Ockerman PA. []
  35. Park S et al: Regular-soda intake independent of weight status is associated with asthma among US high school students. J Acad Nutr Diet 113:106, 2013 []
  36. Park S et al: Association of sugar-sweetened beverage intake frequency and asthma among U.S. adults, 2013. Prev Med 91:58, 2016. []
  37. DeChristopher LR, Uribarri J, Tucker KL: Intakes of apple juice, fruit drinks and soda are associated with prevalent asthma in US children aged 2-9 years. Public Health Nutr 19:123, 2016 []
  38. Lieberoth S et al: Intake of alcohol and risk of adult-onset asthma. Respir Med 106:184, 2012 []
  39. Asthma UK: Asthma and alcohol []
  40. JACI: Alcoholic drinks: Important triggers for asthma. Hassan Vally, BSc (Hons), Nicholas de Klerk, PhD, Philip J. Thompson, FRACP []
  41. No Amount of Alcohol Consumption is Safe []
  42. Alcohol – Bad News for Good Bacteria []
  43. Zhang LL, Gong J, Liu CT: Vitamin D with asthma and COPD: not a false hope? A systematic review and meta-analysis. Genet Mol Res 13:7607, 2014 []
  44. Fares MM et al: Vitamin D supplementation in children with asthma: a systematic review and meta-analysis. BMC Res Notes 8:, 2015 []
  45. Xiao L et al: Vitamin D supplementation for the prevention of childhood acute respiratory infections: a systematic review of randomised controlled trials. Br J Nutr 114:1026, 2015 []
  46. Stanaland BE: Therapeutic measures for prevention of allergic rhinitis/asthma development. Allergy Asthma Proc 25:11, 2004 Jan-Feb []
  47. The Telegraph: Asthma inhalers as bad for the environment as 180-mile car journey, health chiefs say. []
  48. What Are the Side Effects of Asthma Inhalers? Medical Editor: William C. Shiel Jr., MD, FACP, FACR []

Heart Surgery or Plant-Based Diet?

In previous blogs, I shared two documentary films produced by the H.O.P.E. project 1 : “What You Eat Matters” 2 and “From Cancer Patient to Plant-Based Strong Man” 3 . H.O.P.E. have just released another short documentary film about Paul Chatlin, a man with heart disease who was saved from surgery by changing to a plant-based diet.

Paul Chatlin’s Story

Paul Chatlin

In 2013, after being diagnosed with heart disease, Paul’s doctor gave him a simple choice – change his diet or undergo major heart surgery.

At the time, Paul was eating a typical Western diet, with cheese and meat being his favourite foods. Having loved pretty much anything fried in oil, he was given a “nutrition prescription” which required him to give up all these foods and cut out the oil – replacing his habitual diet with a low fat, whole food, plant-based diet.

Having spent his whole life eating one way, he found it a struggle to know what he could now eat and how he could prepare it without using oil. Luckily, he came across and attended a seminar on plant-based nutrition by the world-renowned physician and researcher Dr. Caldwell B. Esselstyn 4, a major player in the famous WFPB documentary film, “Forks Over Knives” 5 and author of his must-read book, “Prevent and Reverse Heart Disease: The Revolutionary, Scientifically Proven, Nutrition-Based Cure.” 6 .

As a result of the seminar, Paul was better equipped and motivated to strike out with his new diet and lifestyle. One month on, his heart pain went away completely. Within a year, his cholesterol levels had dropped from 309 to 122. He also lost over 40 lbs (18 kg).

Paul was so amazed with the health impacts of changing to a plant-based diet, that he started The Plant Based Nutrition Support Group (PBNSG) 7 to help others make the transition to the optimally health WFPB diet.

The film

In this second in the series of H.O.P.E. ‘Plant Power Stories’, Paul shares his journey back to health and encourages us all to give back to our communities.

Final thoughts

If you consider that plant-based eating is of value to the health and well-being of your friends and family, perhaps you could consider sharing this blog with them.

So many people are facing a lifetime on medications and/or having invasive surgery for conditions that could be avoided and treated with simple dietary changes. But, of course, they have to know that such an alternative exists in the first place!

Whilst anecdotal success stories such as Paul’s are likely to inspire hope, all nutritional claims made on this website are always backed up by peer-reviewed, scientific research.


  1. The H.O.P.E. Project. []
  2. I H.O.P.E. You Watch & Share This Film []
  3. The Healing Power of Plants []
  4. Dr Caldwell B Esselstyn’s website. []
  5. Forks Over Knives – The Film []
  6. Prevent and Reverse Heart Disease: The Revolutionary, Scientifically Proven, Nutrition-Based Cure []
  7. The Plant Based Nutrition Support Group []

Diverticulitis and Plant-Based Diets

Diverticulitis is a very unpleasant and potentially lethal condition which is increasingly afflicting populations eating the modern Western diet. This blog will look in some detail at its symptoms, causes and history, as well as potential ways in which you can avoid allowing this often hidden-until-too-late condition to creep up on you.


What are the symptoms of diverticulitis?

The really dangerous thing about this disease is that there can be no symptoms at all until you drop dead. Indeed, it’s reported 1 that nine out of ten people who die of diverticulitis did so without ever even knowing they had it!

Although it can be an asymptomatic disease, there are a range of symptoms that may appear 2 3 , including:

  • cramping
  • bloating
  • abdominal pain, normally on the left side (ranging from slight to excruciating)
  • fever
  • nausea
  • vomiting
  • chills
  • constipation
  • abscesses (the formation of puss)
  • fistula 4
  • intestinal perforation (the formation of a hole in the wall of the colon)
  • sepsis 5

What is diverticulitis?

The clue is in the word itself – the Latin word dīverticulum means turn aside or divert. This diversion is exactly what can happen to some of the food (called chyme) as it passes through the intestines (usually in the colon – also known as the bowel), the muscular walls of which are “diverted” outwards into the abdomen. Peristalsis is a process where the muscles of the intestinal walls contract and relax so that the chyme gradually gets pushed along to the anus and out of the body.

If weak spots are formed in the outer layer of the intestinal wall, the muscles can push outwards laterally, forming pouches or diverticula (diverticulosis). Although the plural is “diverticuli”, many authorities still use “diverticula” for singular and plural. These diverticula can then become inflamed, infected, and start bleeding (diverticulitis). The greatest danger is that infected diverticula will eventually burst, seeping intestinal contents into the bloodstream. This can lead to sudden death.

It’s obvious, then, that diverticulosis occurs first. This condition is usually completely unnoticed and most people never know they have it unless it’s found on a routine colonoscopy. Diverticulitis comes next, and it’s the reason people end up in hospital. It’s reported that 10-25% of individuals with diverticular disease end up developing symptoms such as abdominal pain, bloating, irregular bowel movements, bleeding, or signs of infection. 6 7

Doctors often use the analogy of an over-inflated inner tube poking out through the wall of a tyre. Similarly, increased internal pressure can force the gut to balloon out through weak spots in the intestinal wall. The results are pretty obvious and rather unpleasant:

If the pressure builds up so much and the diverticula rupture, intestinal contents can be pushed into the abdomen and end up in the blood stream. 8

The reason internal pressure can increase so much within the intestines (usually in the colon) is related to the type and quantity of food (chyme) that’s passing through. Continuing the inner tube for intestine analogy – imagine your fingers doing the peristalsis movement and squeezing along a lump of soft mashed potato inside the tube. Should be pretty easy. However, replace the mashed potato with thick gooey molasses and it would be much harder to squeeze it along, resulting in increased internal pressure. If, over a long period of time, your colon is having to squeeze small and compacted lumps, rather than gently contract and dilate around large and soft lumps, damage is pretty inevitable. 9

Most diverticula are not particularly large – around 1-2 centimetres in diameter – but, nevertheless, even at this size they can be big enough to cause symptoms and complications in some people. 10

Dietary fibre & diverticulitis

Just as in the previous blog on constipation 11 , it comes down to the amount of fibre in your diet – too little, and our faeces become small and firm. The same thing is happening within our intestines. If there’s not enough ‘bulk’, the intestines have to squeeze really hard to move the chyme along, and this pressure buildup can force out those bulges and eventually lead to the colon literally rupturing itself.

High-fibre diets make for larger and easier movements through the colon. Plant-based diets contribute a considerable range of intestinal health benefits: adding huge amounts of natural prebiotics and probiotics that permit the gut bacteria (the microbiome) to do their magic: providing anti-inflammatory, anti-cancer, anti-obesity and blood sugar control effects; reducing the risk of stroke, high cholesterol and heart disease; helping to prevent hiatal hernia, brain loss, kidney stones, COPD, Parkinson’s disease, and diabetes; aiding weight loss; improving immunity, and ultimately increasing healthy longevity 12 . That our bodies are able to produce sufficient nitric oxide (a powerful antioxidant) is another factor that is of vital importance to the maintenance of health; and, as previous blogs have considered 13 14 , the quality and quantity of plant foods within our diet dictates the type of microbiome inhabiting all parts of our bodies – from our mouths and intestines to our bladder.

I came across a nice Australian site which stated the following: “We evolved in tandem with our gut microbiome, the bacteria and other microbes that inhabit our gut. They are just as much a part of our digestive system as our own cells. They feed on dietary components that are not absorbed in the small intestine, such as dietary fibre and resistant starch. The microbiome pays its fare by providing us with energy and nutrients that would otherwise have been lost. The large bowel or colon is essentially a fermentation vat. This explains the gas.” 15  It’s always good to see that on the other side of the planet, these WFPB websites are quoting the likes of Drs McDougall, Greger, Popper and Klaper.

Low-fibre diets are not the only risk factor for diverticulitis. Additional contributing factors include smoking, being obese, and eating a diet which is high in red meat and animal fat. One study on meat intake and risk of diverticulitis in men, concluded: “Red meat intake, particularly unprocessed red meat, was associated with an increased risk of diverticulitis.” 16

This is backed up by a 2017 study:

During 894,468 person years of follow-up, we identified 1063 incident cases of diverticulitis….The association between dietary patterns and diverticulitis was predominantly attributable to intake of fiber and red meat.” 17

The modern Western diet contains high levels of animal-based and processed foods. Whilst it’s obvious that animal foods are completely devoid of fibre, some people need to be gently reminded that most processed foods are also very fibre-poor, with most fibre being stripped out during the manufacturing process. 18

Diverticulitis diagnosis

Medical advice should always be sought if you have any symptoms of diverticulitis. Most diagnoses are during an acute attack of abdominal pain.

Your doctor will normally want to give you a physical examination (checking abdominal tenderness) in order to establish the cause of the pain – and there can be a wide range of causes other than diverticulitis.

Women would also normally have a pelvic examination to rule out pelvic disease. After this, the following are possible diagnostic tests:

  • blood and urine tests (checking for signs of infection)
  • pregnancy test for women of childbearing age (ruling out pregnancy as a cause of abdominal pain)
  • liver enzyme test (ruling out liver-related causes of abdominal pain)
  • stool test (ruling out infection in patients with diarrhoea)
  • CT scan (identifying inflamed/infected pouches and to confirm a diagnosis of diverticulitis)

Diverticulitis treatment

The severity of symptoms will determined the treatment. There are two broad classifications used: uncomplicated diverticulitis (usually mild symptoms treated at home) and complicated diverticulitis (usually severe symptoms treated at hospital):

  • uncomplicated diverticulitis
    • antibiotics to fight any detected bacterial infection
    • a liquid diet for a few days until intestines heal naturally
    • when symptoms improve, gradually add solid food to the diet
    • over-the-counter pain relief
  • complicated diverticulitis
    • intravenous antibiotics
    • a tube inserted to drain away any abdominal abscess (if formed)
    • surgery – this would normally be needed if:
      • certain complications occurred, such as:
        • bowel abscess
        • fistula
        • obstruction
        • puncture (perforation) in the colon wall
      • you have a history of multiple episodes of uncomplicated diverticulitis (flare-ups – see below)
      • you have a weakened immune system

Acute flare-ups are not uncommon. It’s reported 19 that 20% of people with diverticula develop a bout of diverticulitis at some stage in their lives.  Best advice – eat lots of fibre and keep hydrated so that you can avoid them developing in the first place.

Two types of surgery for diverticulitis

The two main types of surgery involved with diverticulitis are:

  • primary bowel resection (removing diseased intestinal sections and reconnecting healthy sections)
  • bowel resection with colostomy (when inflammation has been too severe to connect the colon to the rectum, a colostomy will be the option. This involves making an opening in your abdominal wall and connecting it to the still-healthy part of the colon. Waste then passes through the opening into a bag. It’s possible in some cases that the inflammation will reduce and the colostomy can be reversed and the bowel reconnected)

A colonoscopy may be recommended at no less than six weeks after recovering from diverticulitis, particularly if no test was done in the previous year. This might be done in order to exclude any cancer. Some authorities consider 20  that there is no direct link between diverticular disease and colon or rectal cancer. Naturally, a colonoscopy cannot be risked during a diverticulitis attack.

When is eating fibre & a WFPB diet not recommended?

When there’s a flare-up of diverticular disease, especially when hospitalisation was required, it’s generally recommended that a low fibre/liquid-like diet is used as a short-term intervention. Primarily advised as a means of managing gut motility and acute pain, this period of so-called “bowel rest” usually involves abstaining from all solid foods for 2-3 days and consuming only a clear liquid diet, with water or other clear beverages usually being all that’s advised. Once the symptoms have disappeared (that is, when acute pain has subsided) and, of course, under the advice of their doctor, the patient would then be advised to transition to a high-fibre plant diet – ideally of the non-SOS WFPB type.

An absolute must in treating acute diverticulitis is a high-fibre diet if patients wish to prevent complications and recurrences of disease.” 18

Can diverticulitis be reversed by diet?

Once you’ve been diagnosed with diverticulitis, you are strongly recommended to always liaise with your doctor about any dietary changes. However, to avoid recurrence of symptoms, there is little doubt that reducing the pressure within your intestinal tract is key. This is best achieved through eating a diet high in fibre and ensuring you are always fully hydrated.

How much water and fibre is enough? This is a well-debated topic, and was covered in the previous blog 21 , but my research shows that a person eating a balanced WFPB diet is likely to consume up to 100 grams of fibre daily. This is definitely a healthy level. One UK study suggested 22 that for every 5 gram increase in fibre consumed each day, the result was a 15% reduction in disease risk. The same study found that some whole plant fibre sources were especially protective against the disease, namely whole grains and fruits.

However, if a person chooses not to eat an exclusively WFPB diet, it’s generally advised that over 30 grams of fibre is the lower recommended limit. Personally, I would always suggest that WFPB is the way to go. Best be safe than sorry with something that can kill you quickly without you even knowing you had it in the first place.

In terms of daily liquid (ideally water, or black/green tea) consumption, a minimum of around 7 cups (1.75 litres) of water for women and ll cups (2.75 litres) for men is recommended. Plant foods contain mostly water, and so this will add to liquid intake to make it up to the WHO recommendation of 11 cups (2.75 litres) for women and 15 cups (3.75 litres) for men. 23

It’s been shown 2 that even eating just a standard vegetarian diet (with a high intake of dietary fibre compared with the standard meat-based Western diet), is associated with lowering the risk of getting the disease in the first place, of being admitted to hospital, and of dying from the disease. How much more for a WFPB diet with its higher fibre content? Other studies have shown similar results, stating: “Consuming a vegetarian diet and a high intake of dietary fibre were both associated with a lower risk of admission to hospital or death from diverticular disease.” 24

Dr John McDougall considers that it’s certainly worth changing to a high-fibre diet in order to relieve symptoms and prevent further diverticuli: “Contrary to what was once popular opinion, the addition of fibers in the form of brans or high fiber foods has relieved symptoms in 90% of cases of severe colon disease, even with recurrent pain and bleeding. A high fiber diet will also decrease the likelihood of developing new diverticuli. The diverticuli already formed are permanent herniations of the colon, and will not disappear except by surgical removal, which is rarely indicated.” 25

In the following short video, Dr McDougall also reassures us that the bleeding and infection within diverticuli can, in most cases, disappear by making simple dietary changes. The diverticuli themselves remain, although he considers that they would no longer be a problem, so long as a high-fibre diet is maintained.

Diverticulitis rises as fruit & veg consumption drops

Major studies have shown 6 26 beyond any doubt that the risk of developing diverticular disease goes down as fruit and vegetable consumption goes up – and, of course, vise versa. These studies produced the following results:

  • increased diverticular disease is associated with consumption of:
    • beef
    • lamb
    • pork
    • processed meats
    • cookies
    • potato/corn crisps (chips in the US)
    • French fries (chips in the UK!), and
    • white bread
  • physical activity (running/jogging) reduces disease risk
  • decreased diverticular disease is associated with
    • increased fibre intake
  • the strongest correlation of disease reduction is associated with consumption of:
    • fruit, and
    • cereal fibre
  • consumption of all vegetable fibre also reduces disease risk

A further study 7 looked at the effects of using a high-fibre diet in the cases of 100 patients who had been previously diagnosed with acute diverticulitis. After 5-7 years on this diet, 91% of the patients remained completely symptom-free. The authors pointed out that the following respected organisations endorse and encourage the use of a high-fibre diet to prevent diverticular disease:

  • American College of Gastroenterology 27
  • European Association for Endoscopic Surgery 28
  • American Society of Colon and Rectal Surgeons 29
  • World Gastroenterology Organisation 30

Can you eat nuts and seeds if you have diverticulitis?

The usual medical advice around people who have had diverticulitis is that they should avoid eating nuts, seeds, corn, and popcorn. Indeed, some doctors advise that everyone should avoid these foods as a means of avoiding the disease. However, there are at least two recent studies that have blown this unfounded advice out of the water.

A 2009 study 10 stated: “Without any good evidence, certain foodstuffs such as nuts, seeds, popcorn, and corn have long been implicated in the development of diverticulitis and are often advised against by physicians. They were thought to provoke diverticulitis or diverticular bleeding by causing luminal trauma. In a large prospective study of men without known diverticular disease, Strate et al found 31 that nut, corn, and popcorn consumption did not increase the risk of diverticulosis, diverticulitis, or diverticular bleeding.”

A 2012 study 32 stated: “Residue refers to any indigestible food substance that remains in the intestinal tract and contributes to stool bulk. Historically, low-residue diets have been recommended for diverticulosis because of a concern that indigestible nuts, seeds, corn, and popcorn could enter, block, or irritate a diverticulum and result in diverticulitis and possibly increase the risk of perforation. To date, there is no evidence supporting such a practice. In contrast, dietary fiber supplementation has been advocated to prevent diverticula formation and recurrence of symptomatic diverticulosis, although this is based mostly on low-quality observational studies.

Whilst further research is useful, any advice to avoid nuts & seeds does not appear to be based on anything but unfounded conjecture. And, as shown in the 12-year long Seventh Day Adventist Study published in 2001, vegans who didn’t eat any nuts and seeds didn’t live as long as those vegans who did. This is because of the essential fats that nuts and seeds contain – allowing effective absorption of the phytochemicals and anti-oxidants that both groups are eating 33 34

How common is diverticulitis?

Diverticular disease [including diverticulitis] is the most common intestinal disorder.” 35

One study states: “In industrialized nations, diverticular disease affects up to 70% of individuals by 60 years of age, with symptoms that can range from mild gastrointestinal disturbance to incapacitating pain.” 36

Is diverticulitis age-related?

Whilst it’s been conventionally thought that it is an inevitable age-related condition – with the theory being that the intestinal walls tend to weaken as the years and decades pass – this theory can be shown to be untrue. Back in 1907, guess how many cases were recorded? 25! 36 That’s not 25% of the population, but 25 individual cases had been reported in the medical literature. And, as you can see from the graphic photograph above, any autopsy would have had little difficulty in missing diverticulitis if it had been present.

Development of diverticular disease is not an inevitable part of growing older. The colons of people living in underdeveloped countries show a virtual absence of diverticular disease. Healthy, low, pressures in the colon happen when the diet is high in starches, vegetables, and fruits, with their generous content of fiber.” 25

Even in 1916, a study 37 reported that diverticulitis was still not sufficiently documented as a morbid disease in medical literature for it to merit medical recognition.

Diverticulitis – a late 20th Century disease

But in a 1971 study, by the WFPB pioneer Denis Burkitt and his team 38 , it was already recognised as the most common intestinal disease in the US population.

How could this have happened so quickly?

Denis Burkitt showed incredible insight by pointing out that it was most probably down to the fact that even by the 1970’s the Western diet had become low in fibre and high in animal products, processed and highly refined foods. Indeed, it took just half a century from the introduction of rolling milling of flour (which greatly reduced the natural fibre content) in the late 1800’s for diverticulitis to become common in the UK by the 1920’s.

Since then, things have gone from bad to worse.

A number of the first researchers to study diverticulitis nicknamed it a “20th century problem” and a “disease of Western civilisation.” 6

Denis Burkitt’s team back in the 1970’s included in their report 38 a simple diagram which they thought explained the process by which diverticula are formed:

It’s probably no surprise that the US and European populations have the highest rates of diverticular disease in the world, whilst it is rarely found in developing countries before, that is, they adopt the Western diet. 39 7

A 1985 study 40 , again by Denis Burkitt, compared Americans and Africans to see if there were differences in their rates of diverticulitis and other intestinal diseases related to low-fibre diets  – namely, hiatus hernia and pelvic phleboliths 41 . As Dr Greger pointed out in a video on this subject 42 , Burkitt found a huge difference in diverticulitis rates between the Africans eating the high-fibre diet (less than 1% of the population) and the Americans eating the low-fibre diet (more than 50% of the population):

Your poo can give a clue

This might not be the most tasteful subject, but you can tell a lot about the likely state of your intestines by checking on what your poo (stool or faeces) looks like.  If you’re regularly constipated, and diverticula have already formed in the colon, stagnant faecal matter ends up clogged in the diverticula “bubbles”. 39 This can, in turn, trigger inflammation of the intestinal wall, resulting in the above-mentioned symptoms. The following chart is one of the standard charts used to get clues from your poos:

The Bristol Stool Chart provides a graphic version of various stool samples.

Developed by Dr. Ken Heaton from the University of Bristol in the late 1990’s, it’s used primarily as a clinical communication aid in categorising stool types 43 .

It’s only meant to be an unofficial guide, but does allow us to get a general idea of the classification of our poo, providing, thereby, a reasonably good indicator of both the diet we’re eating and the likely state of our intestines.

  • types 1 and 2 are typical of a constipated individual
  • type 3 is borderline normal
  • type 4 is the “gold standard for the perfect stool”
  • type 5 is heading in the direction of diarrhoea
  • types 6 and 7 reflect an individual in diarrhoea distress

If you want to delve deeper into the subject of bowel movements and constipation, Dustin Rudolph, PharmD has written a useful article44

It’s worth repeating that the balance of gut bacteria can be altered by chronic constipation and eating a low-fibre diet. Rather than a colon full of “good” (healthy) bacteria, there’s an increase in “bad” (infectious) bacteria that populate the colon. And it’s the presence of the latter bacteria that can further increase the chances of an infection developing.

Low-fibre diets do NOT cause diverticulitis!

Just to confuse the issue, a 2012 North Carolina study 45 came up with completely different conclusions than everything else that’s been said above about diverticulitis (and, of course, constipation) being powerfully linked to low-fibre diets. The study concluded:

In our cross-sectional, colonoscopy-based study, neither constipation nor a low-fiber diet was associated with an increased risk of diverticulosis.

By understanding the reason that they found no association, we can learn something about the quantity of fibre necessary to make a significant difference to your risk of developing chronic constipation and/or diverticulitis, plus we can learn a lot about how clinical trials can come up with misleading information.

In this study, they took two groups and carefully ensured that one group received only 8 grams of fibre a day while the other group received 25 grams of fibre a day. When they compared the results, there was no significant difference in the rates of diverticulosis and, thus they announced to the world that we do not need to bother eating a high-fibre diet in order to maintain good gut health.

The story was taken up all over the world, with headlines like:

“Diets high in fiber won’t protect against diverticulosis, study finds.46 47

“High-fibre diet may not protect against diverticulosis.” 48

“Paleo Diet: More Evidence That Fiber is Not A Good Thing.” 49

And not only did the Paleo crowd get involved and believe the study findings, even medical journals jumped on the band wagon, quoting the conclusions of the above study:

“Diverticulosis and dietary fiber: rethinking the relationship…A high-fiber diet does not protect against asymptomatic diverticulosis.” 50

So, what’s going on here?

Firstly, good news about bad habits is always attractive for those who want to justify their own bad dietary habits – tucking into a juicy beefburger and fries with impunity, rather than having to worry about eating all that rabbit food!

However, the fatal flaw in the study was identified pretty quickly by other studies, including the following:

Most importantly, how this study is interpreted is limited by the overall low-fiber intake within the study population. Although the authors performed analyses stratified by fiber intake and found no significant difference between those in the lowest (2.5–10.1 g) and highest quartiles (18.4–50.3 g) of fiber intake, few patients in the uppermost quartile had a true high fiber intake. An analysis reflecting clinical recommendations of high-fiber (>25 g) vs low-fiber (<14 g) diets may have yielded different results.” 51

To clarify just what this flaw of the study was, Dr Greger 52  drew an excellent analogy with early vitamin C studies. It takes around 10 mg of vitamin C a day to avoid developing scurvy 53 .

Back in the 1700’s, James Lind 54  wondered if scurvy in sailors could be avoided if they were given wedges of lemon each day. So he tested his theory. One group were given one wedge of lemon, and the other group were given three wedges of lemon a day. He found no difference at all between the groups, and the same ratio came down with scurvy.

So, did this prove that low vitamin C levels are not associated with the development of scurvy? Of course not. In order to prevent scurvy, it’s necessary to ingest at least 10 mg of vitamin C, and a single wedge of lemon only has around 2 mg. So, even with three wedges of lemon, you’re still only getting around 6 mg.

See the analogy?

The group eating the highest amount of fibre in the above North Caroline study 45 were only eating around 25 grams of fibre a day, which is less than the US minimum recommended daily allowance of around 32 grams. As Dr Greger says: “They didn’t even make the minimum. So they compared one fiber-deficient diet to another fiber-deficient diet—no wonder there was no difference in diverticulosis rates.

Whenever looking at any study results that appear “too good to be true”, it’s always worth checking on what was compared with what – after all, even a McDonald’s Big Breakfast is healthy when compared with…smoking tobacco or inhaling asbestos!

Final thoughts

As with many things in life, simple is best. The best form of cure for diverticular disease is prevention. And the best form of prevention is undoubtedly provided by eating a high-fibre diet, keeping well-hydrated, and getting plenty of regular daily exercise.

I can’t really think of a better way of ending than by quoting a closing comment by Dustin Rudolph, PharmD, writing for T Colin Campbell’s Center for Nutrition Studies (CNS), made at the end of his article on diverticular disease:

Eat plants. Get lots of fiber. Live happy. And avoid doctors and pharmacists if at all possible by adopting a whole food, plant-based lifestyle. Your body will thank you for many years to come.” 18

References & Notes

  1. J Chapman, M Davies, B Wolff, E Dozois, D Tessier, J Harrington, D Larson. Complicated diverticulitis: is it time to rethink the rules? Ann Surg. 2005 Oct;242(4):576-81; discussion 581-3. []
  2. Spiller, R. C. (2015). Changing views on diverticular disease: impact of aging, obesity, diet, and microbiota. Neurogastroenterology & Motility, 27(3), 305-312. [] []
  3. Health Navigator New Zealand. Diverticular disease and diverticulitis. Retrieved from .nz/health-a-z/d/diverticular-disease-diverticulitis/ []
  4. A fistula, in this case, is an abnormal passage between a hollow or tubular organ and the body surface, or between two hollow or tubular organs. In this case, it is more commonly between the intestine and the bladder. []
  5. Diverticulitis: Causes, Symptoms & Treatment. By Alina Bradford. June 12, 2018. []
  6. Aldoori W, Ryan-Harshman M. Preventing diverticular disease. Review of recent evidence on high-fibre diets. Can Fam Physician. 2002 Oct;48:1632-7. [] [] []
  7. Unlu C. Daniels L, et al. A systemic review of high-fibre dietary therapy in diverticular disease. Int J Colorectal Dis. 2012;27:419-427. [] [] []
  8. N S Painter. Diverticular disease of the colon. The first of the Western diseases shown to be due to a deficiency of dietary fibre. S Afr Med J. 1982 Jun 26;61(26):1016-20. []
  9. Painter N, Truelove S, et al. Segmentation and the localization of intraluminal pressure in the human colon, with special reference to the pathogenesis of colonic diverticula. Gastroenterology. 1968;54(Suppl):778-780. []
  10. Beckham H, Whitlow CB. The Medical and Nonoperative Treatment of Diverticulitis. Clin Colon Rectal Surg. 2009;22:156-160. [] []
  11. Constipation & Plant-Based Diets []
  12. Topic: Fibre. []
  13. Are Nitrates & Nitrites Bad For Us? []
  14. Greens: Chewing vs Juicing []
  15. Gut Health. []
  16. Cao, Y., Strate, L. L., Keeley, B. R., Tam, I., Wu, K., Giovannucci, E. L., & Chan, A. T. (2017). Meat intake and risk of diverticulitis among men. Gut, gutjnl-2016. []
  17. Gastroenterology. 2017 Apr;152(5):1023-1030.e2. doi: 10.1053/j.gastro.2016.12.038. Epub 2017 Jan 5. Western Dietary Pattern Increases, and Prudent Dietary Pattern Decreases, Risk of Incident Diverticulitis in a Prospective Cohort Study. Strate LL et al. []
  18. CNS: What Is Diverticular Disease and How to Treat It. By Dustin Rudolph, PharmD. February 14, 2019. [] [] []
  19. Patient. Diverticula (including Diverticulosis, Diverticular Disease and Diverticulitis). Retrieved from http:// []
  20. Mayo Clinic: Patient Care & Health Information Diseases & Conditions: Diverticulitis []
  21. Constipation & Plant-Based Diets []
  22. Crowe, F., Appleby, P., Allen, N., & Key, T. (2011). P2-54 Diet and risk of diverticular disease in the European prospective investigation into cancer and nutrition (EPIC)-Oxford cohort, a prospective study of British vegetarians and non-vegetarians. Journal of Epidemiology and Community Health, 65(Suppl 1), A234-A234. []
  23. How Many Glasses of Water Should We Drink a Day? Michael Greger M.D. FACLM May 25th, 2015 Volume 24. []
  24. Diet and risk of diverticular disease in Oxford cohort of European Prospective Investigation into Cancer and Nutrition (EPIC): prospective study of British vegetarians and non-vegetarians. BMJ 2011; 343 doi: []
  25. Dr John McDougall: Diverticular Disease – Diverticulosis & Diverticulitis. [] []
  26. Crowe FL, Balkwill A, et al. Source of dietary fibre and diverticular disease incidence: a prospective study of UK women. Gut. 2014;63:1450-1456. []
  27. ACG: Diverticulosis and Diverticulitis []
  28. European Association for Endoscopic Surgery and other Interventional Techniques []
  29. American Society of Colon and Rectal Surgeons: Treatment of Sigmoid Diverticulitis (Revised). []
  30. World Gastroenterology Organisation: Diverticular Disease. []
  31. Strate L L, Liu Y L, Syngal S, Aldoori W H, Giovannucci E L. Nut, corn, and popcorn consumption and the incidence of diverticular disease. JAMA. 2008;300(8):907–914. []
  32. Tarleton S, DiBaise JK. Low-residue diet in diverticular disease: putting an end to a myth. Nutr Clin Pract. 2011 Apr;26(2):137-42. []
  33. Adventist Health Study-1 Publication Database []
  34. Why Vegans Need Fats And DHA by Joel Fuhrman, M.D. []
  35. Diverticulosis: When Our Most Common Gut Disorder Hardly Existed. Michael Greger M.D. FACLM July 17th, 2015 Volume 25 []
  36. J Y Wick. Diverticular disease: eat your fiber! Consult Pharm. 2012 Sep;27(9):613-8. doi: 10.4140/TCP.n.2012.613. [] []
  37. W H M Telling, O C Gruner. Acquired diverticula, diverticulitis, and peridiverticulitis of the large intestine. Brit J Surg. 4:468-530, 1917. []
  38. N S Painter, D P Burkitt. Diverticular disease of the colon: a deficiency disease of Western civilization. Br Med J. 1971 May 22;2(5759):450-4. [] []
  39. Boynton W, Floch M. New strategies for the management of diverticular disease: insights for the clinician. Ther Adv Gastroenterol. 2013;6(3):205-213. [] []
  40. D P Burkitt, J L Clements Jr, S B Eaton. Prevalence of diverticular disease, hiatus hernia, and pelvic phleboliths in black and white Americans. Lancet. 1985 Oct 19;2(8460):880-1. []
  41. Pelvic phleboliths are are round clusters of calcium that develop in the walls of a vein. They can vary in size but are usually around 5 mm across. They most commonly appear in the veins surrounding the pelvis. They can be caused by constipation and straining, which can damage pelvic veins. []
  42. Diverticulosis: When Our Most Common Gut Disorder Hardly Existed. Michael Greger M.D. FACLM July 17th, 2015 Volume 25. []
  43. Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol. 1997. []
  44. Dustin Rudolph, PharmD. The Anatomy Of A Bowel Movement (And How To Cure Constipation).  August 14, 2013. []
  45. A F Peery, R S Sandler, D J Ahnen, J A Galanko, A N Holm, A Shaukat, L A Mott, E L Barry, D A Fried, J A Baron. Constipation and a low-fiber diet are not associated with diverticulosis. Clin Gastroenterol Hepatol. 2013 Dec;11(12):1622-7. doi: 10.1016/j.cgh.2013.06.033. [] []
  46. ScienceDaily: Diets high in fiber won’t protect against diverticulosis, study finds []
  47. UHC HealthTalk: Diets high in fiber won’t protect against diverticulosis. January 23, 2012. []
  48. The Washington Post: High-fibre diet may not protect against diverticulosis. []
  49. Paleo Diet News: Paleo Diet: More Evidence That Fiber is Not A Good Thing. Posted on February 1, 2012. []
  50. L L Strate. Diverticulosis and dietary fiber: rethinking the relationship. Gastroenterology. 2012 Feb;142(2):205-7. []
  51. R E Burgell, J G Muir, P R Gibson. Pathogenesis of colonic diverticulosis: repainting the picture. Clin Gastroenterol Hepatol. 2013 Dec;11(12):1628-30. doi: 10.1016/j.cgh.2013.08.046. []
  52. Does Fiber Really Prevent Diverticulosis? Michael Greger M.D. FACLM July 20th, 2015 Volume 25 []
  53. Scurvy is a disease resulting from a lack of vitamin C (ascorbic acid). Early symptoms include weakness, feeling tired, and sore arms and legs. Without treatment, decreased red blood cells, gum disease, changes to hair, and bleeding from the skin may occur. As scurvy worsens there can be poor wound healing, personality changes, and finally death from infection or bleeding. []
  54. Tröhler U (2003). James Lind and scurvy: 1747 to 1795. []

Constipation & Plant-Based Diets

Studies suggest 1 2 that around 20% of people in Westernised countries suffer from constipation. That’s a lot of unpleasant and largely unnecessary toilet trouble by any standards. But is there a simple, drug-free remedy? You can bet your beans and greens there is!

Fibre, fibre, fibre

The most common lifestyle choice associated with the development of constipation is eating a low-fibre diet.

It still comes as something as a surprise just how many people are completely unaware that fibre can only be found in foods derived from plants – fruit and veg, beans, whole grains, etc – and that there is ZERO fibre in meat, dairy products, and eggs.

The average daily fibre intake in the UK is 17.2 grams/day for women and 20.1 grams/day for men, with a government recommendation of a minimum of 30 grams/day 3 . In the US, the recommendations vary from 19-38 grams/day, whilst US fibre intake is even less than the UK, at around 16 grams/day 4 5 . And, because these are averages, it means there are plenty of people eating considerably less than this.

A previous blog 6 discussed fibre in more detail, and pointed out that eating as much as 100 grams of fibre daily was quite normal in earlier human evolution.

In those countries where traditional diets contain much more fibre, it’s no surprise to find that constipation is much less common. But how can we know that it’s the fibre that’s making so much difference? Well, studies have looked at the changes that occur when such countries adopt the modern Western diet, which is much lower in fibre content. And what they’ve found is that constipation prevalence increases. 7 8

Constipation by country

There’s a very detailed list of reported constipation cases available at 9 , but the following selective chart from a 2008 study 10  shows a common finding: namely, that women tend to suffer more than men.

Key: United States (US), United Kingdom (UK), France (FR), Germany (GE), Italy (IT), Brazil (BR) and South Korea (SK).

Problems arising from constipation

There are a number of complications which may arise from constipation 11 12 , including:

  • haemorrhoids (from “straining at the stool”)
  • anal fissures
  • rectal prolapse
  • faecal impaction (also called malignant constipation), which may lead to:
    • bowel obstruction
    • nausea
    • vomiting
    • tender abdomen
  • encopresis (where soft stool from the small intestine bypasses the impacted faecal mass in the colon)

How to prevent and alleviate constipation

It’s pretty obvious that the most sensible and natural method will involve increasing fibre content in the diet.

In children, studies show 13 14 that a lower intake of dietary fibre differentiates children with chronic constipation from those who have regular bowel movements. It’s so sad that children have to undergo such suffering simply because their parents and carers fail (whether through ignorance or conscious choice) to feed them a diet that maintains their gut health. Of course, it’s not just the problem of constipation that’s at issue here; maintaining a healthy gut microbiome from early life is vital for overall health through childhood and into old age 15 16 17 18 . And it’s such an obvious yet largely unappreciated fact 19 that our GI tract (along with all the trillions of essential bacteria, fungi and other microbes therein) is best maintained by a whole food plant-based diet rather than a diet of processed and/or animal foods.

As would be expected, therefore, additional studies show that increasing dietary fibre improves constipation and significantly reduces the need for laxatives in all societal groups:

  • children 20
  • young adults 21
  • elderly people 22 , and
  • post-surgery patients 23

When fibre supplementation may be necessary

Naturally, the first and best option is to increase the consumption of high-fibre foods. This is because, by eating whole plant foods, we don’t just facilitate easier gut transit, but the fibre itself and the natural healthy bacteria included with plants act as probiotics and prebiotics for our gut bacteria, and a variety of plants provides a vast array of minerals, vitamins, and an almost inestimable number of beneficial phytochemicals.

However, there are situations where chewing away on fibrous plant food is not an option, and so, in the following cases, fibre supplements may be the best option:

  • individuals lacking teeth (edentulism)
  • patients who can’t swallow easily or at all (dysphagia)

Prescribing laxatives is a very general knee-jerk reaction of medical professionals. They seem to choose this because they don’t appear to believe their patients have the wherewithal to significantly alter their diets. However, suggesting fibre supplements, in the case of the above two conditions, or changing to a high-fibre diet, in the case of most patients, is far more successful than merely pouring laxatives down your throat while still eating the same constipating diet. When the second best alternative (fibre supplements) are offered, evidence suggests 24  that around 60% of constipated patients can dispense with the laxatives they had been previously taking.

Different types of fibre supplements

The following have been shown to be effective for constipation relief:

  • psyllium (Metamucil) 25 (although prunes have been shown 26  to be more effective than psyllium)
  • methylcellulose (Citrucel) 27
  • Japanese konjac root (glucomannan) 28

But, I repeat, the first and best option is to transition to a plant-based diet (ideally non-SOS WFPB) unless, of course, you have no teeth or cannot swallow easily. And, even the latter two cases, I would suspect that there may be some way found to ensure whole plant foods are eaten, even if they have to be pulped or liquidised to some extent. I have some personal experience of this situation, since my father developed COPD 29 and dysphagia. Being crippled and having to be cared for my my mother, she was told that he would only ever be able to eat pureed food. However, she found that with some careful selection of foods, he was able to eat “solid” food almost until the time of his eventual death.

Dehydration & constipation

Even mild dehydration is a very common factor in cases of constipation 30 31 . This has also been found 20  to be the case in young constipated children. And it’s easy to understand why this is the case, and how it links inextricably with diet, when you realise that whole plant foods contain loads of water, while processed and animal foods can contain considerably less – and also usually contain loads of dehydrating salt.

Becoming dehydrated, without being aware of it, is much easier and more widespread than most of us realise. This can be seen from a US study 32 which found a shocking 75% of US citizens were chronically dehydrated.

In patients with functional chronic constipation, it’s been shown 33  that combining fibre and fluid (25 grams and 1.5-2.0 litres, respectively) on a daily basis was more effective for constipation relief than simply taking fibre alone.

It’s no surprise, then, that Dr Greger includes water consumption as one of the essential items in his Daily Dozen list 34 , stating that “…authorities from Europe, the U.S. Institute of Medicine, and the World Health Organization recommend between 2 to 2.7 liters of water a day for women. That’s 8 to 11 cups a day for women, and 10 to 15 cups a day for men. Now but that’s water from all sources–not just beverages–and we get about a liter from food and the water our body actually makes. So these translate into a recommendation for women to drink 4 to 7 cups of water a day, and men 6 to 11 cups, assuming only moderate physical activity at moderate ambient temperatures.” 35 .

Constipation & cow’s milk

Many children with chronic constipation are found 36 to be allergic to cow’s milk, manifesting IgE antibodies 37 to cow’s milk antigens38 . It’s always worthwhile for parents to ensure that any difficulties occurring during potty training are not associated with constipation resulting from the child drinking cow’s milk.

This is no insignificant matter, since consumption of cow’s milk has been found 39 to be significantly higher in infants and children with constipation and anal fissure than in those without these disorders.

And it gets even worse. Colonoscopies revealed 40  that around 50% of constipated, cow’s milk-allergic children and adolescents had lymphoid nodular hyperplasia 41 , compared with 20% of controls. The same study also found that around 33% of all cow’s milk-allergic individuals had a significantly higher number of intraepithelial T cells 42 , indicating an enhancement of local immune responses against food antigens. Another study of children with lymphoid modular hyperplasia found 43  that in 43 of the 52 individuals a diagnosis of cow’s milk or multiple food hypersensitivity was made.

Such activation of the immune system is known 44 to affect gastric motility 45 , thus indicating a likely role for an immune response to food antigens in cases of constipation.

Cow’s milk or soy milk?

Cutting out cow’s milk totally, in the diets of those children with cow’s milk sensitivity and constipation, has been shown 46  to result in significant improvement in up to 66% of cases.

In a small-scale study 47 of children with constipation, 100% of the participants had full resolution of chronic functional constipation when soy milk was used as a replacement for cow’s milk.

A further study found 48 that when cow’s milk was reintroduced, constipation returned within 5-10 days.

Previous blogs 49 50 have discussed in much more detail the range of health issues associated with cow’s milk. In basic terms, for all humans, irrespective of age, there’s absolutely no nutritional need for “baby calf growth fluid” 51 to be included in the diet. And, for a significant number of both children and adults who experience constipation, it would seem a sensible plan to try cutting out cow’s milk completely to see whether relief of symptoms follows.

Final thoughts

So, getting lots of fibre, drinking plenty of fluids and avoiding cow’s milk seem to be the major routes towards non-drug prevention and treatment of constipation in all age groups. One area we haven’t covered is regular physical exercise, which, counter to popular belief, does not have any overwhelming study evidence to support its value for constipation treatment or avoidance. Some studies consider that it can be an important adjunct for males 52 and females 53  of all age groups in the prevention and treatment of constipation. However, other studies, including the following 2017 French study, question whether increasing exercise per se has any positive effect:

The benefi[t] of increasing water intake or daily physical exercise in the treatment of chronic constipation have a lack of evidence, except specific situations such as elderly, hospitalized, institutionalized, dehydrated people or people consuming fluids less than 500mL/day. Change in environmental defecation conditions or bowel habits are probably anecdotal recommendations.” 54

Yet other authorities consider 55 that, in some cases of particularly intense exercise, constipation can be worsened. More research is needed on which level of activity (stationary yoga movements, gentle walking or marathon running, for instance) has what effect on constipation.

Whilst lack of exercise is particularly important as we age and run the risk of becoming too sedentary 56 , the increasing rates of childhood obesity – and the associated reduction in physical exercise – are reported by some studies as revealing a worrying increase in cases of constipation and other GI health concerns 57 58 .

My personal experience is that the effects of exercise appear to be determined, at least to some extent, on the quality of diet you are consuming. If you’re already eating a low-fibre diet and then exercise, I have no doubt that it might lead to increased constipation; however, when a high-fibre diet is your norm, exercise may not have the same effect. A comparison study would be of interest in this respect.

What all studies agree on, however, is that the main and overreaching factor of importance in avoiding and treating constipation is fibre, fibre and more fibre.

So, in conclusion, whilst it’s easy to say that best means of achieving healthy GI tract activity is to follow a varied WFPB diet, keep hydrated and ensure that you get plenty of daily exercise, when we have had a lifetime of practising ingrained and unquestioned habits, it can be really difficult to make such lifestyle and dietary changes.  However, ensuring that our children do not fall into bad habits will both protect them and encourage us to embrace healthier practices ourselves.

References & Notes

  1. Higgins PD, Johanson JF. Epidemiology of constipation in North America: a systematic review . Am J Gastroenterol . 2004; 99: 750–759. []
  2. Chiarelli P, Brown W, McElduff P: Constipation in Australian women: prevalence and associated factors. Int Urogynecol J Pelvic Floor Dysfunct 11:71, 2000 []
  3. British Nutrition Foundation: Dietary fibre. []
  4. Hoy MK, Goldman JD. Fiber intake of the U.S. population: What We Eat in America, NHANES 2009–2010. United States Department of Agriculture website. []
  5. U.S. Department of Agriculture and Agricultural Research Service. What We Eat in America: Dietary Fiber (g): Usual Intakes from Food and Water, 2003-2006, Compared to Adequate Intakes. National Health and Nutrition Examination Survey (NHANES) 2003-2006. United States Department of Agriculture website. []
  6. Fibre! Fibre! Fibre! []
  7. Yang XJ et al: Epidemiological study: Correlation between diet habits and constipation among elderly in Beijing region. World J Gastroenterol 22:8806, 2016 []
  8. Holmboe-Ottesen G, Wandel M. Changes in dietary habits after migration and consequences for health: a focus on South Asians in Europe. Food Nutr Res . 2012;56. []
  9. by Country for Constipation []
  10. AP&T. A multinational survey of prevalence and patterns of laxative use among adults with self‐defined constipation. A. WALD C. SCARPIGNATO S. MUELLER‐LISSNER M. A. KAMM U. HINKEL I. HELFRICH C. SCHUIJT K. G. MANDEL. First published: 01 September 2008 []
  11. Walia R, Mahajan L, Steffen R (October 2009). “Recent advances in chronic constipation”. Curr Opin Pediatr. 21 (5): 661–6. []
  12. McCallum IJ, Ong S, Mercer-Jones M (2009). “Chronic constipation in adults”. BMJ. 338: b831. []
  13. Kranz S et al: What do we know about dietary fiber intake in children and health? The effects of fiber intake on constipation, obesity, and diabetes in children. Adv Nutr 3:47, 2012. []
  14. Castillejo G et al: A controlled, randomized, double-blind trial to evaluate the effect of a supplement of cocoa husk that is rich in dietary fiber on colonic transit in constipated pediatric patients. Pediatrics 118:e641, 2006. []
  15. Gut Microbiota & Depression []
  16. Fibromyalgia, Probiotics & Gut Microbiota []
  17. Physical Activity for Disease Prevention & Healthy Gut Microbiome []
  18. Multiple Sclerosis (MS), Serotonin & Gut Microbiota []
  19. Two Types of Gut Bacteria: Plant Eaters’ & Meat Eaters’ []
  20. Castillejo G et al: A controlled, randomized, double-blind trial to evaluate the effect of a supplement of cocoa husk that is rich in dietary fiber on colonic transit in constipated pediatric patients. Pediatrics 118:e641, 2006 [] []
  21. Woo HI et al: A Controlled, Randomized, Double-blind Trial to Evaluate the Effect of Vegetables and Whole Grain Powder That Is Rich in Dietary Fibers on Bowel Functions and Defecation in Constipated Young Adults. J Cancer Prev 20:64, 2015 []
  22. Howard LV, West D, Ossip-Klein DJ: Chronic constipation management for institutionalized older adults. Geriatr Nurs 21:78, 2000 Mar-Apr []
  23. Griffenberg L et al: The effect of dietary fiber on bowel function following radical hysterectomy: a randomized trial. Gynecol Oncol 66:417, 1997 []
  24. Sturtzel B et al: Use of fiber instead of laxative treatment in a geriatric hospital to improve the wellbeing of seniors. J Nutr Health Aging 13:136, 2009 []
  25. Ramkumar D, Rao SS: Efficacy and safety of traditional medical therapies for chronic constipation: systematic review. Am J Gastroenterol 100:936, 2005 []
  26. Prunes vs. Metamucil vs. Vegan Diet. Michael Greger M.D. FACLM March 15th, 2013 Volume 12 []
  27. Mounsey A, Raleigh M, Wilson A: Management of Constipation in Older Adults. Am Fam Physician 92:500, 2015 []
  28. Yen CH et al: Long-term supplementation of isomalto-oligosaccharides improved colonic microflora profile, bowel function, and blood cholesterol levels in constipated elderly people–a placebo-controlled, diet-controlled trial. Nutrition 27:445, 2011 []
  29. Chronic Obstructive Pulmonary Disease (COPD) is an umbrella term used to describe progressive lung diseases including emphysema, chronic bronchitis, and refractory (non-reversible) asthma. This disease is characterised by increasing breathlessness. []
  30. Eur J Clin Nutr. 2003 Dec;57 Suppl 2:S88-95. Mild dehydration: a risk factor of constipation? Arnaud MJ []
  31. Murakami K et al: Association between dietary fiber, water and magnesium intake and functional constipation among young Japanese women. Eur J Clin Nutr 61:616, 2007 []
  32. Survey of 3003 Americans, Nutrition Information Center, New York Hospital-Cornell Medical Center. April 14, 1998. []
  33. Anti M et al: Water supplementation enhances the effect of high-fiber diet on stool frequency and laxative consumption in adult patients with functional constipation. Hepatogastroenterology 45:727, 1998 May-Jun []
  34. Dr. Greger’s Daily Dozen Checklist. Michael Greger M.D. FACLM September 11th, 2017 Volume 38 []
  35. How Many Glasses of Water Should We Drink a Day? Michael Greger M.D. FACLM May 25th, 2015 Volume 24 []
  36. Cow’s milk protein allergy in children: identification and treatment. The Pharmaceutical Journal15 MAY 2018. By Hetal Dhruve, Joanne Walsh, David Mass, Adam Fox. []
  37. IgE antibodies: If you have an allergy, your immune system overreacts to an allergen by producing antibodies called Immunoglobulin E (IgE). These antibodies travel to cells that release chemicals, causing an allergic reaction. This reaction usually causes symptoms in the nose, lungs, throat, or on the skin. []
  38. Antigens are toxins or other foreign substances which induce an immune response in the body, especially the production of antibodies. []
  39. Andiran F, Dayi S, Mete E: Cows milk consumption in constipation and anal fissure in infants and young children. J Paediatr Child Health 39:329, 2003 []
  40. Turunen S, Karttunen TJ, Kokkonen J: Lymphoid nodular hyperplasia and cow’s milk hypersensitivity in children with chronic constipation. J Pediatr 145:606, 2004 []
  41. Lymphoid nodular hyperplasia (LNH) generally presents as an asymptomatic disease, but it may cause gastrointestinal symptoms like abdominal pain, chronic diarrhoea, bleeding or intestinal obstruction. []
  42. Intraepithelial T cells (IETs), residing at the epithelial barrier in the gastrointestinal tract, are an epitome of tissue-resident T cells. Tissue-resident T cells are long-lived, nonrecirculating T cells that provide rapid immune responses independent of peripheral T cell recruitment. []
  43. Clin Gastroenterol Hepatol. 2007 Mar;5(3):361-6. Colonic lymphoid nodular hyperplasia in children: relationship to food hypersensitivity. Iacono G, Ravelli A, Di Prima L, Scalici C, Bolognini S, Chiappa S, Pirrone G, Licastri G, Carroccio A. []
  44. Hermann GE, Tovar CA, Rogers RC: Induction of endogenous tumor necrosis factor-alpha: suppression of centrally stimulated gastric motility. Am J Physiol 276:R59, 1999 []
  45. Gastric Motility: contractions of gastric smooth muscle that serves two basic functions: ingested food is crushed, ground and mixed, liquefying it to form what is called chyme. Chyme is then forced through the pyloric canal into the small intestine, a process called gastric emptying. []
  46. Carroccio A et al: Chronic constipation and food intolerance: a model of proctitis causing constipation. Scand J Gastroenterol 40:33, 2005 []
  47. Crowley ET et al: Does milk cause constipation? A crossover dietary trial. Nutrients 5:253, 2013 []
  48. Iacono G et al: Intolerance of cow’s milk and chronic constipation in children. N Engl J Med 339:1100, 1998 []
  49. If You Want Enough Calcium, Forget Milk []
  50. Cow’s Milk – But It Looks So Innocent… []
  51. ‘Cow’s milk’ as baby calf growth fluid: video with Michael Klaper. []
  52. Harvard Men’s Health Watch. Chronic constipation: A strain for men. Published: September, 2008 []
  53. Diabetes Metab Syndr Obes. 2017; 10: 513–519. Effects of a proposed physical activity and diet control to manage constipation in middle-aged obese women. Sayed A Tantawy, Dalia M Kamel, Walid Kamal Abdelbasset, and Hany M Elgohary []
  54. Presse Med. 2017 . Jan;46(1):23-30. doi: 10.1016/j.lpm.2016.03.019. Epub 2017 Jan 5. [Diet and lifestyle rules in chronic constipation in adults: From fantasy to reality…]. [Article in French]. Fathallah N, Bouchard D, de Parades V. []
  55. Exercise Causes Constipation! By Ashok T Jaisinghani, October 4, 2016 in Diet & holistic health []
  56. NIH: Concerned About Constipation? []
  57. PLoS One. 2014; 9(2): e90193. Physical Activity and Constipation in Hong Kong Adolescents. Rong Huang, Sai-Yin Ho, Wing-Sze Lo, and Tai-Hing Lam []
  58. Hippokratia. 2015 Jan-Mar; 19(1): 11–19. Constipation in Childhood. An update on evaluation and management. I Xinias and A Mavroudi []

How Can Parents Get Toddlers To Eat Healthily?

There are a number of methods to ensure that toddlers eat healthily, and there’s probably been no other time in human history when it’s been more important to do so. Child obesity and all its associated metabolic diseases are hitting children at ever younger ages 1 2 3 . Whilst it’s so easy to blame Big Business and national governments, the primary responsibility for ensuring our children grown up healthy is now, as it always has been, mostly in the hands of their own parents and carers.

Definition of terms

Although not written in stone, the stages of early childhood are conventionally understood as the following:

  • newborn – between 0 and 2 months
  • infant – between 2 and 12 months
  • toddler – between 12 months and 4 years

Getting it right from the start

The most important time to ensure the development of healthy eating habits is arguably during the early weaning process – that is, the period when the baby is transitioning from mother’s breast milk to solid food. I am taking for granted that we would all agree the newborn’s ideal first nutrition (for around the first 6 months) should always be exclusively mother’s breast milk whenever possible. All the evidence points in this direction 4 5 6 .

Bad habits are hard to break

Between around 6 and 12 months of age, the infant will be introduced to “solid” food. It’s during this stage that major mistakes can be made, and bad eating habits (food high in calories and low in nutrients) can be set in motion.

If, however, appropriate food (high in nutrients and sufficient in calories for growth) is introduced, ingrained bad habits within the infant and toddler stages can be avoided, with the remaining years of childhood (and probably adulthood) thus standing a much better chance of being free from the need to put endless effort into undoing such habits – yo-yo dieting, continual fighting to escape the pleasure trap, with all its tempting and addictive bliss points 7.

The importance of good example

Whether or not less-favourable eating habits have been established, parents and carers need to ensure that they act as good examples. This means:

  • eating a healthy and varied balance of foods themselves
  • eating at regular times
  • sharing meals – making each meal a special family event, rather than simply eating separately in front of the TV
  • encouraging toddlers to eat 3 meals a day plus 2 healthy snacks. This can avoid those hunger pangs that can result in unhealthy ‘grazing’ between meals and then overeating during meals

Children who grow up seeing their parents and carers forever on diets or bingeing on unhealthy foods is not something that will act as a good example.

One recent story I heard was of a nutritionist who was asked to intervene in a family where the young child refused to eat anything that even appeared to be a vegetable or a fruit, preferring instead to eat a diet existing more or less solely of sweets, crisps and cakes. The nutritionist advised that containers of bite-sized carrots and celery be left around the kitchen for the child to be attracted to eat. The nutritionist then walked past the veg and said something along the lines of “Oh look! How lovely! Carrots. I love them” and then tucked into them with glee. When the father was asked to do the same, as a means of giving positive feedback to the child, he picked up a carrot, bit into it and pulled a face that would have been better suited to a person who had just swallowed a bumble bee. Naturally, the child saw his father’s reaction and the nutritionist could immediately identify the major reason that the child had developed such unhealthy habits.

Toddlers in the kitchen

Even from the youngest age, infants will be influenced by the sorts of foods they encounter. This isn’t just a matter of flavours, but also of smell, texture, colour, and general variety – the colours of the rainbow.

The relationship parents and carers have to matters relating to food preparation itself will have an effect on the growing child. Involving the toddler from an early age in making meals and understanding the nature of different foods can be of great help in ensuring the child grows up with knowledge about and control over dietary matters.

Any parent will find that toddlers simply love experimenting with the selection and preparation of food. This playful experience is a great way for them to try different foods in the kitchen. It, along with meal times, should be a fun way to spend time with the family. The idea of simply placing already-prepared meals in front of a toddler may be attractive in terms of saving preparation time; however, doing so would tend to miss the exciting and productive times when he or she (or a group of toddlers, be they friends or siblings) could be involved in handling, selecting, chopping, peeling, and even cooking (with careful supervision, of course).

I remember that when I was young I asked my mother what tongue was – you know, those greyish-red slices of meat that bear no resemblance to that huge, dripping muscular organ lolling out of the mouths of cows. I’d been eating it for years and it hadn’t dawned on me that what we called slices of tongue was actually part of a dead animal. I mean, they called candyfloss candyfloss, but you don’t floss candy with it! Anyway, once I discovered what it was, I never touched it again. Had I been responsible for cutting it out of the mouth of the dead cow and then slicing and boiling it, perhaps I would have developed an aversion to it at an even earlier age. Who knows?


Toddler or parent temptation?

Avoiding the temptation to give in to a toddler’s potential demands for sweets and treats is increasingly difficult for parents, what with the ubiquitous advertising campaigns and availability in toddler-height shelves in most shops these days. Even when it comes to those special times, it’s still so important to avoid making unhealthy junk foods a treat or a central part of festivals, birthdays and other celebrations.

If a toddler grows up thinking that a real treat is enjoying a healthy salad rather than being thrown a bag of prawn cocktail crisps or a bag of Haribo Starmix, it’s a pretty good indication that something has been done right!

Of course, parents themselves have to engage in the same fight with sweet and junky temptations that they may well have had since their own childhoods. In this case, fighting one’s own natural desires for sweet indulgence is a preface to allowing one’s children to grow up with more freedom from cravings and learned preferences associated with such toxic foods.

And it hardly needs saying saying that using foods in any way to establish or maintain emotional control is to be avoided. As soon as emotional states (positive or negative) are inextricably linked to food, problems can arise. The art of developing a sense of well-being which is separate from the need for oral satisfaction is something that one would wish all children to learn at an early age. It allows them freedom to seek emotional satisfaction and achievement in other more productive spheres of life.

Eat when hungry

Thus, it’s useful for toddlers to grow up learning that they eat when they are hungry – not when they are forced to do so or because they are bored or depressed.

In any case, toddlers have tiny stomachs which, if filled with unhealthy foods, will leave no room for more essential nutrients. This is where portion control comes into its own. In order to ensure that the toddler does not get used to over-eating, the type and quantity of foods they are presented with should be taken into consideration. Just as there should be no justification for “forcing” an infant or toddler to eat something that he or she does not want to eat, it is equally unhelpful for them to force food down when their body is telling them that they have eaten enough.

Allowing infants and toddlers to exercise some choice in the foods they put into their mouths is advisable – so long as the selection is from healthy and interesting foods. If they don’t want to eat at the moment, fine – be patient and wait until they feel hungry. In the meantime, they can see their parents enjoying the same sorts of food, without having made a big issue of the child’s not eating at that moment. A relaxed atmosphere around the dining table is always likely to produce healthy and easy-going dietary habits in the child.

When hunger hits and ‘seconds’ are required, they should be from a selection of vegetables or fruit. If the toddler wants more immediately after having eaten their meal, it might be a good idea to encourage them to wait for a little while in order to let the food “settle” – allowing leptin to do its job 8 – before they have extra portions.

Learning portion control early in life is a useful means of preventing over-eating in future years. This is not usually a problem, however, with those who eat a non-SOS WFPB diet, since the range of foods within this dietary regime tend to be self-limiting. It’s only when the stomach is filled with high calorie/low nutrient alternatives 9 that over-eating is something that parents should be really concerned about – both for themselves and their children – being that processed foods are carefully manufactured to be addictive “pleasure traps” as they hit those “bliss points” 10 .

Anticipation can be better than participation

Learning ‘satisfaction-delay’ is a really good skill for children to learn young. If a toddler gets what he or she wants immediately upon request, they don’t learn how to delay pleasurable experiences, and learning how to live with the delayed pleasure of eating is a useful skill that spills over into most aspects of child and adult life.

Delaying gratification isn’t a new concept. Back in 300 BC, Aristotle saw that the reason so many people were unhappy was that they confused pleasure for true happiness. True happiness, according to Aristotle, is about developing habits and surrounding yourself with people who grow your soul.” 11

Variety (within reason) matters

Introducing a variety of foods is important and, as stated before, not forcing a child to eat a particular food, if they feel a strong dislike for it, is a sensible move. The chances are that they will change their minds later and try the foods if they see adults enjoying them and not making an issue of them. Patience is the key. This planet of ours grows so many wonderful edible plants that finding alternatives should never be a problem for the attentive parent.

Whilst toddlers are, of course, too young to receive pocket money and run the risk of spending it on sweets etc, any food choices they are able to make at this young age should be from as healthy a range of options as possible. This means keeping only healthy foods in the house and trying to avoid the aisles in supermarkets which draw their attention to unhealthy foods – unfortunately, this is virtually impossible in the modern Western food shopping experience.

Take care with carers

Parents should make their dietary rules very clear to any carers who take responsibility for the toddler. Bad habits learned from carers can cause conflict in the child when they return to their parents and find that they are being told a different story about what dietary habits are or are not acceptable. This applies to both the type and quantity of foods themselves and the regularity and form of dining habits.

Thinking before drinking

In terms of drinks, toddlers should not get used to filling up on sugary drinks. It should go without saying that infants receive their best source of liquids from their mother’s breast milk. Providing drinking fluids during weening is, of course, a natural and essential route, so long as the liquid provided is plain water.

It’s hard to find any authority that would advise parents to give their toddlers fizzy/sugary drinks. The best thing is to avoid all sugary drinks completely so that the child becomes accustomed and perfectly content with simple tap water.

Parents would be wise to do a bit of careful research before deciding to follow the crowd in giving their toddlers cow’s milk. Parents usually feed cow’s milk to their children because they had it themselves and it’s something that is, well, just done! However, much of this is based on an arguably inaccurate belief that cow’s milk is necessary to ensure children get enough calcium 12 . There are some pretty convincing arguments, based on solid research 13 12 , that would caution against feeding cow’s milk to your child, especially when there are plenty of fortified plant milk alternatives 14 to choose from.

It may come as a surprise to some people, but even fruit juices are not an ideal drink 15 , especially if they have added sugar or artificial sweeteners. If, however, they are to be given to toddlers, they should be diluted with water.

Final thoughts

The foregoing is by no means a comprehensive overview of the many ways in which parents can encourage healthy eating habits in their children during the earliest stages of their lives. For my part, I wish my parents had followed even a few of the ideas outlined above. My overly sweet childhood diet resulted in countless rotten teeth and fillings during my adolescent years. This has been accompanied with a life-long struggle against using sweet and fatty junk foods as a reward for a tiring day, a pick-me-up when feeling a little low, and a treat whenever there’s a “y” in the day!

This is why engendering good dietary habits from a young age is so very important. It’s easier to do the right thing when you don’t have to continually undo the wrong.

I wouldn’t wish on anyone a lifetime of being good at bad habits.


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  4. Research on Breastfeeding & Breast Milk at the NICHD []
  5. British Nutrition Foundation: SACN’s ‘Feeding in the First Year of Life’. []
  6. NHS: Benefits of Breastfeeding []
  7. Bliss Points, Pleasure Traps & Wholefood Plant-Based Diets. []
  8. Leptin – The “Fat” Hormone? []
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  10. Bliss Points, Pleasure Traps & Wholefood Plant-Based Diets []
  11. Psychology Today: The Benefits of Delaying Gratification. Are You Avoiding Pain or Living With Purpose? Dec 26, 2017. []
  12. If You Want Enough Calcium, Forget Milk [] []
  13. Cow’s Milk – But It Looks So Innocent… []
  14. Plant Milks Are Churning Up The Ground []
  15. Fruit Juice by []

Improve Blood Flow By Hanging Upside Down?

It might sound a bit odd, but apparently it’s possible to improve metabolic measures related to blood flow simply by hanging upside down. However, get it wrong and you might end up killing yourself.

It’s well-known that regular aerobic exercise is good for the heart. But various yoga positions also appear to do a similar trick without the need for so much sweating.

One particular yoga pose of specific interest is the upside down position. Of course, as you can see below, there are plenty of different ways of achieving this.

What are the upside down benefits?

A 2011 review 1  into the benefits of yoga in general considered that upside down (or inverted) yoga poses were of benefit to the cardiovascular system:

Inverted poses encourage venous blood flow from the legs and pelvis back to the heart and then pumped through the lungs where it becomes freshly oxygenated. Many studies 2 3 4 show yoga lowers the resting heart rate, increases endurance, and can improve the maximum uptake and utilisation of oxygen during exercise.

There are plenty of yoga websites 5 6 7 8 that give advice on the best way to achieve this inverted pose – variously called supported headstand, sirsasana, inversions, and so forth.

Any yoga’s good yoga

Naturally, this is not the only yoga pose that studies have shown has health benefits. Studies suggest a wide range of benefits, such as:

  • neurological disorders 9 , including:
    • multiple sclerosis 10
    • stroke 11
    • epilepsy 12
    • Parkinson’s disease 13
    • dementia 14
    • Alzheimer’s 15
  • hypertension 16
  • obesity 17
  • diabetes 18
  • depression 19

The list goes on and on…

Dying to be upside down

However, you should be warned that this is not one of those things where a little is good and a lot is even better. Too much inversion can kill 20 .

In 2009, a guy called John Jones, who lived in Utah, died after spending 28 hours stuck upside down in a cave 21 , most likely from asphyxiation.

Upside down lungs

It transpires that our lungs evolved to sit on top of all the other organs for a very good reason. They are such delicate organs that it doesn’t take them long to get squashed by the larger and heavier organs such as the liver and intestines that usually sit below them. 22

This isn’t a problem for sloths, since they have their lungs “taped” to their ribs 23 .

But for us mere humans, having our heads directly underneath our feet for extended periods of time means that the lungs simply can’t absorb enough oxygen given the restricted space they have to work within.

Upside down brain

And it’s not just our lungs that have difficulty. Our bodies are set up to move blood around when we’re upright. Our blood vessels are customised to make sure blood doesn’t pool in our feet. This system is a “one-way street”, since our bodies didn’t evolve to prevent blood from pooling in the brain. This is patently not the case with bats. They have one-way valves in their arteries that prevent blood from flowing backwards. This is why they are able to hang upside down without the blood rushing to their heads 24 .

However, unlike bats, Batman would get into all sorts of vascular trouble (with or without the help of Robin) – ruptured blood vessels and potential brain haemorrhage included.

Upside down heart

And the heart is no lover of too much life down under 25 . It’s thought that heart failure accounts for most upside down fatalities. Just as with the brain, when the heart is above the head, it pumps more slowly and starts to receive more blood than it has the capacity to deal with at any one time. The result is that it begins to have a hard time maintaining blood pressure. Eventually, it will lose its ability to move sufficient blood around to maintain all the body’s essential functions.

Hanging around for too long will eventually kill you – a risk which increases as we age or if we are sick.

Inversion can be torture

It should be remembered that inversion was used as a torture method is ye olde days. It combined pain with a smattering of humiliation. Often the torture of choice for those sinners with unorthodox beliefs, it was used by the Romans with Christians and the Spanish with Jews and Muslims 26 27  . The Japanese even have a word for it – Tsurushi or “reverse hanging” 28 .

Nice to see how relaxed that monk-like executioner appears!

Another thing they used to do was to keep the victim inverted for some time and then make them stand upright again. Apparently, this is very painful as the blood pools to the feet again. Of course, they’re then hung upside down again. This process usually kills them within 8 to 10 hours.

Oh how inventive we humans are…

Final thoughts

It’s probably the case that any exercise is good exercise – whether it’s resistance training with weights, aerobic, or yoga. The important thing is to ensure you get plenty of regular daily exercise – either 90 mins low-moderate intensity (e.g. walking) or 45 mins of high-intensity exercise (e.g cycling, running, or rowing). It’s generally suggested 29 that you can work out your maximum heart rate by simply subtracting your age from 220. Then you can think of low-moderate intensity as being 50 – 70% of the resulting figure, whilst high-intensity would be 70-85%.

Spending a little time upside down appears to be something worth considering – however, some methods of achieving this are better than others…


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  6. Yoga Journal: Everybody Upside-Down []
  7. YouTube video: How to Do a Headstand (Sirsasana) Yoga []
  8. DoYouYoga: 10 Most Popular Yoga Inversions []
  9. J Clin Neurosci. 2017 Sep;43:61-67. doi: 10.1016/j.jocn.2017.05.012. Epub 2017 Jun 7. Evidence based effects of yoga in neurological disorders. Mooventhan A, Nivethitha L. []
  10. PLoS One. 2014 Nov 12;9(11):e112414. doi: 10.1371/journal.pone.0112414. eCollection 2014. Yoga for multiple sclerosis: a systematic review and meta-analysis. Cramer H, Lauche R, Azizi H, Dobos G, Langhorst J. []
  11. Cochrane Database Syst Rev. 2017 Dec 8;12:CD011483. doi: 10.1002/14651858.CD011483.pub2. Yoga for stroke rehabilitation. Lawrence M, Celestino Junior FT, Matozinho HH, Govan L, Booth J, Beecher J. []
  12. Cochrane Database Syst Rev. 2017 Oct 5;10:CD001524. doi: 10.1002/14651858.CD001524.pub3. Yoga for epilepsy. Panebianco M, Sridharan K, Ramaratnam S. []
  13. Trials. 2017 Nov 2;18(1):509. doi: 10.1186/s13063-017-2223-x. The effects of yoga versus stretching and resistance training exercises on psychological distress for people with mild-to-moderate Parkinson’s disease: study prxotocol for a  randomized controlled trial. Kwok JYY, Kwan JCY, Auyeung M, Mok VCT, Chan HYL. []
  14. Int J Geriatr Psychiatry. 2017 Jan;32(1):118. doi: 10.1002/gps.4538. The therapeutic effects of yoga in people with dementia: a systematic review. Du Q, Wei Z. []
  15. Res Gerontol Nurs. 2014 Jul-Aug;7(4):171-7. doi: 10.3928/19404921-20140218-01. Epub 2014 Feb 26. The effect of chair yoga in older adults with moderate and severe Alzheimer’s disease. McCaffrey R, Park J, Newman D, Hagen D. []
  16. Exp Clin Endocrinol Diabetes. 2016 Feb;124(2):65-70. doi: 10.1055/s-0035-1565062. Epub 2015 Nov 17. The Efficacy and Safety of Yoga in Managing Hypertension. Cramer H. []
  17. Prev Med. 2016 Jun;87:213-232. doi: 10.1016/j.ypmed.2016.03.013. Epub 2016 Apr 4. A systematic review and meta-analysis on the effects of yoga on weight-related outcomes. Lauche R, Langhorst J, Lee MS, Dobos G, Cramer H. []
  18. Prev Med. 2017 Dec;105:116-126. doi: 10.1016/j.ypmed.2017.08.017. Epub 2017 Sep 4. The effects of yoga among adults with type 2 diabetes: A systematic review and meta-analysis. Thind H et al. []
  19. Depress Anxiety. 2013 Nov;30(11):1068-83. doi: 10.1002/da.22166. Epub 2013 Aug 6. Yoga for depression: a systematic review and meta-analysis. Cramer H, Lauche R, Langhorst J, Dobos G. []
  20. Quora: How long could a human being survive hanging upside down if they’re being fed, hydrated, etc. Would spending one’s life hanging upside down shorten one’s lifespan? Amandi Dilshara. Oct 24 2019. []
  21. ABC News: Man in Utah Cave Faced Tough Odds, Doctors Say John Jones’ upside down position in the cave left rescue workers little time. By LAUREN COX. Nov. 26, 2009. []
  22. HowStuffWorks: How Your Lungs Work. BY CRAIG FREUDENRICH, PH.D. []
  23. National Geographic: SCIENCE & INNOVATION. To Breathe Upside-Down, Sloths Tape Organs To Their Ribs. BY ED YONG. PUBLISHED APRIL 23, 2014. []
  24. Bat Worlds: Bat Anatomy. Nov 5, 2013. []
  25. How StuffWorks: How Your Heart Works. CARL BIANCO. []
  26. The Marseille Tarot Revealed: A Complete Guide to Symbolism, Meanings & Methods. By Yoav Ben-Dov. []
  27. Bustle: 7 Incredibly Disturbing Execution Methods From The Middle Ages (You Really Should Not Read This) By LARA RUTHERFORD-MORRISON. May 14 2015. []
  28. Wikipedia: Tsurushi. []
  29. Mayo Clinic: Exercise intensity: How to measure it. []

Lose weight Without Exercising or Making Any Dietary Change?

Tackling obesity without exercise or dietary changes? Everyone’s heard of fat tissue (also called adipose tissue), but what about brown adipose tissue (BAT) and “beige” adipose tissue – ever heard of them? Although sounding pretty unappetising,  these adipocytes1 share the unique ability of being able to convert chemical energy into heat and, thereby, play a critical role in promoting something called non-shivering thermogenesis – a little-known process that is central to the human species’ ability to spread across the globe and, as an interesting sideline, can potentially help in weight-loss without even having to lift a single barbell or place a tentative trainer on that running machine gathering dust in your garage. Or is it just too good to be true?

BAT & beige adipocytes

Until relatively recently, the physiological role of BAT and beige adipocyte depots were thought to be limited to small mammals and only relevant to humans when they were neonates (newborn infants). Puppy fat or baby fat was thought to all-but disappear with the passing years into adulthood. However, the discovery that there’s more BAT in adult humans than previously thought, has led to studies which show enthusiasm for BAT’s potential role in treating obesity and other disorders caused by sustained positive energy balance (more calories in than out). Adult humans having more BAT than previously thought was revealed 2 3 during routine scans  (FDG-PET scans4 to detect metastatic cancers. 5  Autopsies were also able to reveal these fat concentrations. 6

Brown & white fat

BAT (often abbreviated to “brown fat”) is found in virtually all mammals, but notably in newborn humans and mammals that hibernate 7 . Of course, the usual white adipose tissue (“white fat”) that we think of when we talk about fat is found in far higher quantities. 8 . The following provides an overview of the differences between the brown and white fat tissue:

The main differences between brown and white fat can be summarised as:

  • white contains a single lipid droplet while brown contains numerous smaller droplets
  • brown contains a much much higher number of (iron-containing) mitochondria – hence the brown (rusty) colour of the tissue 9
  • brown contains more blood capillaries than white – hence a better oxygen supply, more nutrient-provision and the ability to distribute the produced heat throughout the body

Two types of BAT

BAT itself can also broken down into two types which have similar functions but are located in different cell populations within the body: 10

  • brown adipocytes found in comparatively larger separate deposits within the body, and
  • “beige” or “brite” (“brown in white”) adipocytes found interspersed within white adipose tissue and which develop out of white adipocytes under the stimulation of the sympathetic nervous system (SNS) 11
Brown adipose tissue in a woman shown in a PET/CT scan exam.

BAT in infants & adults

BAT in infants eventually “turns into” white fat in adulthood. In infancy, however, it tends to be located in the following “depots” within the body:

  • interscapular 12
  • supraclavicular 13
  • suprarenal 14
  • pericardial 15
  • paraaortic 16
  • around the pancreas, kidney and trachea 17

BAT in adults tend to be located in the following depots:

  • supraclavicular
  • suprarenal
  • paravertebral 18
  • mediastinal 19
  • paraaortic 20

It’s still not absolutely clear whether these adult BAT depots are the “classical” brown or the beige/brite fat. 21 . However, BAT is metabolically active in adult humans 22  and decreases in quantity as we age 23 . Another characteristic of BAT is that it becomes more visible (that is, becomes more metabolically active) with cold exposure – as can be seen by analysing it with PET scans.

BAT & thermoregulation

The primary function of BAT is thermoregulation. That is, ensuring the body remains sufficiently warm in cold environments. It achieves this autonomic heating of the body in two ways: firstly, through shivering thermogenesis (causing muscles to shiver) and, secondly, through non-shivering thermogenesis (as the name suggests – heating the body without shivering) – an adaptive thermogenesis response. The first option, shivering thermogenesis, will certainly warm up the body, but at the expense of using up relatively more precious energy.

However, the unique ability of BAT to convert energy stores (brown fat) into heat (without needing to use energy-sapping shivering) is achieved through a process within BAT mitochondria (the energy-producing cellular power plants). Instead of the usual process, where ATP (the energy molecule) is produced during oxidative phosphorylation, a protein called thermogenin or UCP1 (Uncoupling Protein 1) promotes a proton leak in the inner membrane of the mitochondria, dissociating the oxidative phosphorylation of substrate from the generation of ATP. In essence, this results in an increase in non-shivering thermogenesis, where the metabolic rate increases, and chemical energy is shunted into heat energy that can then spread around the body via the bloodstream.

This means the endothermic organisms (you and me) stand a better chance of survival against unfavourable environmental conditions with the least possible consumption of energy stores 24 . This can be seen in a little more clearly in the following diagram:

Just to be clear, all cells of endotherms are able to give off heat to some degree, particularly when body temperature is below a regulatory threshold; but BAT is highly specialised for this non-shivering thermogenesis. This is largely because of two of the features mentioned above: firstly, each BAT cell has a higher number of mitochondria compared to typical cells and, secondly, these mitochondria have a higher-than-normal concentration of thermogenin (UCP1) in the inner membrane.

Why do newborns have so much BAT?

In newborn infants, BAT comprises around 5% of body mass (located on the upper half of the spine and toward the shoulders). At this age, infants are at a much higher risk of hypothermia than adults. This is largely because of the following:

Infants have:

  • underdeveloped nervous systems that don’t respond quickly and/or appropriately to cold via vasoconstriction (the contraction of blood vessels in and just below the skin)
  • inability to move away from cold materials or air currents or towards warmer materials/environments
  • low amount of musculature and an inability to shiver (shivering thermogenesis)
  • lack of thermal insulation such as subcutaneous fat and fine body hair
  • higher ratio of body surface area (proportional to heat loss) to body volume (proportional to heat production)
  • higher proportional surface area of the head
  • the obvious inability to use adult ways of keeping warm – putting clothes on, exercising, drying their skin, etc

Thus, heat production in BAT provides infants with an alternative means of heat regulation.

Evolutionary advantage of BAT

Mammals (and birds, to some extent) have the unique ability to maintain their core temperature independently of the external environmental temperature. This homeothermic 25 ability has allowed great evolutionary success compared to poikilotherms2627

The main components of this response to temperature are:

  • thermal insulation
  • non-shivering thermogenesis, and
  • shivering thermogenesis 28

From an evolutionary point of view, excess energy expenditure aimed at maintaining core temperature represents a trade-off between survival and the maintenance of energy stores, since energy availability will usually represent a major limiting factor to growth and reproduction. Thus, moving from an insulative response (energy neutral), to a non-shivering and eventually shivering thermogenesis will require a progressively greater dissipation of energy stores, as can be seen in the following chart.

Model of adaptive thermogenesis. As the environmental temperature decreases from thermoneutrality, the adaptive thermogenesis response moves from insulative to non-shivering and eventually shivering thermogenesis. This progression is mirrored by an increase in the energy expenditure required to maintain the core temperature. Green, energy expenditure due to basal metabolic rate; red, expenditure due to adaptive thermogenesis.

Over recent evolutionary development, humans gained the ability to “control” their environment by using clothes and controlling the temperature in their buildings. As a result, cold exposure is a relatively rare condition and, unless acclimatised, individuals would tend to respond by shivering thermogenesis – where heat is a side product of uncontrolled shivering – also known as muscle fasciculation 29

Losing weight & improving health with BAT

Recent discoveries regarding BAT may, it’s claimed, lead to new methods of weight loss, since brown fat (when exposed to cold temperatures) takes calories from normal fat and burns it. As well as this, adaptive (non-shivering) thermogenesis also appears to promote glucose disposal. To test this weight-loss ability of BAT, it would involve exposing subjects to cold temperatures and monitoring whether they do, in fact, lose weight without having to exercise or change dietary patterns. The following is a selection of some BAT studies that throw some light on this subject.

A 1961 study 30 when individuals had prolonged exposure to cold, showed that they became resilient and stopped displaying shivering thermogenesis, indicating that other mechanisms were being recruited.

In 2009, four separate studies 31 32 33 34 indicated clearly that BAT was present in a significant number of adults and that there was a correlation between its presence and activity related to indices of healthy metabolism.

In 2010, a study 35 showed that there was an inverse correlation between BAT activity and between obesity, diabetes and ageing – that is, the more active BAT was, the less obesity, diabetes and ageing was seen.

Naturally, up to this point, the relationship was one of correlation and no causal mechanism had been established. However, researchers were very interested in finding out more about the capacity and activity of human BAT as a therapeutic means of treating the various metabolic consequences of obesity. The majority of the consequent studies focused on this BAT adaptive thermogenesis response by exposing volunteers to cold.

A 2011 study 36 exposed individuals to short but intense cold (e.g. immersing a limb in ice-cold water). Whilst they showed that this does indeed increase energy expenditure, it’s a method that fails completely to correspond with day-to-day experience and is impossible to sustain over time.

Additional research demonstrated that such extreme cold exposure was not necessary to stimulate sustained physiologic adaptive thermogenesis. It could be stimulated by even mild cold exposure as that controlled within normal (and bearable) climate-controlled buildings. This was shown in a 2010 crossover study 37 which looked at the effects of the adaptive thermogenesis response to minimal changes in environmental temperature. Healthy volunteers underwent two 12-hour periods in a whole room calorimeter (Metabolic Chamber) at 19 and 24 °c to monitor energy expenditure (EE). Results indicated that such minimal modulation of environmental temperature was sufficient to increase EE by around 6%. Might not seem much but, if projected over a 24 hour period, it would represent a drop of 100 kcal in an individual of between 70-80 kg.

Hormonal axes and organ-system response to mild cold exposure.

In addition to burning extra calories, exposure to mild cold (with the resulting increase in non-shivering thermogenesis) was shown to be sufficient to drive an adrenergic response 38 , which promotes lipolysis39 (with fatty acids being the preferred substrate in BAT depots) and increased postprandial glucose disposal. Additionally, the intervention generated an increase in cortisol 40  and a state of relative insulin resistance during fasting, which indicate an activation of the stress response. These, and other responses are shown in the adjacent table.

The researchers point out that, although the magnitude of this change may appear insignificant – only one fifth of the negative energy balance recommended to achieve sustained weight loss – it is relevant to note that, over a 1-year period (all things being equal), these differences would be equivalent to a 20-day fast and to a daily 30-min walk at a moderate pace.

A subsequent 2013 study 41 confirmed BAT contributes to energy expenditure (EE) in response to mild cold exposure – namely, 12-hour metabolic chamber exposure to either 19 or 24 ° C.

Two other 2013 studies showed, in the first case 42 , that a short-term, moderate (10 days acclimatisation with exposure at 17 ° C daily for 2 hours) cold exposure was sufficient to increase the quantity of BAT, and, in the second case 43 , that a longer period of time (6 weeks acclimatisation with exposure at 17 ° C daily for 2 hours) resulted in “significant fat mass reduction“- as shown in the following photos and chart:

BAT activation was shown to improve glucose homeostasis 44 and insulin sensitivity 45 in humans. Additional studies 46 47 looked at BAT and the hormone FGF-21 (fibroblast growth factor 21 production). FGF-21 is a critical metabolic regulator that governs glucose and lipid (fat) metabolism and plays an important role in the treatment of metabolic diseases, such as T2D (type 2 diabetes) and obesity. In T1D (type 1 diabetes), FGF-21 also reduces blood glucose levels and prevents diabetic complications.  It was demonstrated that BAT activation through cold exposure can up-regulate circulating FGF-21 in humans by 37%. FGF21 improves insulin sensitivity and glucose metabolism which may partially explain its longevity promoting benefits.

This offers hope for those with impaired insulin function who might benefit from BAT activation. And it’s not just those with clinically impaired insulin function, such as type 2 diabetics, who could benefit from this. Over time, even mildly elevated blood glucose levels in otherwise healthy non-diabetic humans are associated with other physiological damage. This has been shown to result in higher levels of the damaging AGE’s (advanced glycation end products – found in animal products, processed and fried/barbecued/roasted fatty foods), as well as damage to the brain, eyes, tendons, endothelial cells and the cardiovascular system 48 49 50 .

In a longer 2014 study 51 over four consecutive months, environmental temperature was modulated overnight – 24 ° C (run-in period), (cold acclimatisation), 24 ° C (wash-out period), and 30 ° C (heat acclimatisation). After a month of exposure to mild cold (19 ° C ), BAT volume and activity almost doubled, but after a month of exposure to warm temperature (30 ° C), BAT activity was negligible. The researchers commented that: “Remarkably, the increase in BAT activity following the cold acclimatisation was accompanied by a significant increase in postprandial glucose disposal, but only during mild cold exposure.

One study 52 looked at levels of irisin (a relatively newly discovered hormone) as a result of both intense exercise and cold exposure. Irisin is nicknamed the “exercise hormone” since  it’s released during moderate aerobic endurance activity and is known to be an anti-obesity and anti-diabetes hormone that regulates fat tissue and blood sugar, improving insulin sensitivity, bone quality/quantity 53 54 , and building lean muscle mass. In essence, irisin is thought to help reduce obesity by converting white fat to brown fat 55 . Being that irisin is released by muscles during physical exercise 56 , if cold-exposure also releases irisin, then perhaps the metabolic benefits of such exposure would be similar to those when irisin is released through exercise. And, indeed, this study demonstrated that this appears to be the case.

And irisin has other interesting effects. A study 57 on the reasons why healthy centenarians are healthy noted that they tend to have increased serum irisin levels, whilst irisin levels were significantly lower in younger patients with myocardial infarction 58 . So, although somewhat an aside to the main thrust of this blog, such findings are likely to prompt further research into the role of irisin in vascular disorders and life span extension.

Another hormone, adiponectin 59 , has associations with both BAT activation and centenarians. It’s been shown 60 that when BAT is activated through cold exposure, adiponectin levels increase within just two hours, resulting in a 70% increase in circulating adiponectin in adult men. Interestingly, both male and female centenarians (as well as their offspring) have been found 61  both to have genetics which boost adiponectin and to have generally higher circulating levels of adiponectin. This suggests a further link between BAT activation and longevity – this time because of the increased production of adiponectin. Furthermore, these high concentrations of plasma adiponectin in centenarians were associated 62 with other favourable metabolic factors as well as with lower levels of C-reactive protein 63  and E-selectin64 . It was mentioned earlier that BAT activation results in the production of FGF-21 – a hormone that improves insulin sensitivity and glucose metabolism. The latter benefits may explain why this hormone has been shown 46  to play a role in promoting longevity in humans.

In relation to fat and irisin, it was shown 65 that applying irisin to human preadipocytes (cells that can be transformed into different fat cells through the process of adipogenesis) , ordinary white adipocytes could be changed into beige adipocytes. This helps confirm the role of irisin as a myokine66 that can expand beige adipocyte mass, increasing the non-shivering thermogenesis capacity and, thereby, promoting a shift from inefficient and non-sustainable shivering thermogenesis to more efficient and sustainable non-shivering thermogenesis. In the following diagram, FGF-21 (fibroblast growth factor 21) promotes BAT’s activity of cold-induced non-shivering thermogenesis in humans.

Model of interplay between shivering and non-shivering thermogenesis. Exposure to cold promotes shivering in non-acclimated individuals, with the release of irisin. This response is unsustainable and costly from an energy-conservation perspective. Irisin promotes the expansion and differentiation of beige adipocytes, which increase resilience to cold enhancing non-shivering thermogenesis and delays the onset of shivering.

All the above studies indicate both that human BAT is extremely plastic, and that activation via cold exposure is necessary to generate a significant metabolic response.

Final thoughts

So, merely reducing the environmental temperature in your home could help to lose some body weight (represented by an additional energy expenditure of around 100 kcal) without actually undergoing exercise or changing one’s dietary habits. However, the amount of body fat you could lose through undergoing even colder and, consequently, more uncomfortable temperatures is something that I can’t imagine many people wanting to opt for as a weight-loss method.

Of course, integrating a bit of low temperature “therapy” might reduce one’s heating bills. And, of course, there is another weight-loss method associated with temperature modulation – namely, sweating your socks off in a sauna, albeit really just water that you’ll lose, and you’ll put the weight back on pretty soon afterwards when you rehydrate.

However, there is another simple non-exercise/non-dieting weight-loss method which is similar in effect to turning down the thermostat – namely, something called a standing desk. A standing desk is simply a matter of raising the height of one’s table (and hence the computer , book or paperwork thereon) and standing instead of sitting. Interestingly, this method has been shown 67 to increase calories burnt (in this case in young schoolchildren):

Another study 68 found that standing burned an extra 0.15 calories per minute, on average, compared with sitting. Men burned an extra 0.2 calories per minute while standing, which was twice as much as women, who burned an extra 0.1 calories. This was because men they typically have more muscle mass than women. This would mean that a person weighing around 63 kg (140 pounds/10 stones), replacing sitting with standing for six hours a day would burn an extra 54 calories per day.

Naturally, pharmaceutical companies may well try to come up with a “magic pill” that will stimulate BAT activity without the need for subjecting oneself to cold temperatures – maybe an injection or pill to stimulate BAT activity without having to ensure cold temperatures; but experience teaches us that most of these pharmaceutical wonder cures have unpleasant side effects and rarely prove as effective as their manufacturers initially claim.

So, whether of itself, or even when combined with another simple non-exercise/non-dietary change weight-loss method, it would seem that the benefits are interesting, though not comparable with the weight-loss benefits of a combination of exercise and eating a low-fat plant-based diet.

References & Notes

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  14. Suprarenal – of, relating to, situated in, or occurring in the region above or anterior to the kidneys []
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  38. Andrenergic relates to nerve cells in which adrenaline, noradrenaline, or a similar substance acts as a neurotransmitter. The result of this is that there is a stimulation of the sympathetic nervous system (SNS), which is responsible for the fight-or-flight response, which is triggered for example by exercise or fear causing situations. This response dilates pupils, increases heart rate, mobilises energy, and diverts blood flow from non-essential organs to skeletal muscle. These effects together tend to increase physical performance/energy usage momentarily. []
  39. Lipolysis is the breakdown of fats and other lipids by hydrolysis to release fatty acids. []
  40. Cortisol helps to control blood sugar levels, regulate metabolism, help reduce inflammation, and assist with memory formulation. It has a controlling effect on salt and water balance and helps control blood pressure. []
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  63. High C-reactive protein (CRP) levels in your blood indicate inflammation in your body, possibly indicating an infection or other condition. []
  64. E-selectin is also associated with inflammation, mediating leukocyte rolling (adhesion) on activated endothelial cells at inflammatory sites. It may also support tumour cell adhesion during hematogenous metastasis (cancer spread) and may play roles in angiogenesis (cancer development) and haematopoiesis (production of blood cells). []
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Vegan Pie Comes Top in British Pie Awards 2019

Oh the scandal! The outrage! Grass-eaters winning a competition that should be dominated by pies filled with traditional steak and kidney, bacon and egg, pork and venison? And, to top it all, taking place in the hallowed heart of pork pie heaven, Melton Mowbray – the home of the classic pork pie.

For the sensitive souls (and taste buds) of the noble omnivore, this egregious affront to human taste and dignity comes far too soon on the back of Greggs’ launch of their ridiculously successful vegan sausage roll 1 . So successful, indeed, that it’s been credited as the cause of the 7% rise in the company’s share value 2 .

The vegan “pie” was produced by a company called Jon Thorner’s of Somerset 3 . As if it wouldn’t be so bad winning just one prize, they ended up winning a total of three awards at the recent 2019 British Pie Awards 4  for their Curried Sweet Potato & Butternut Squash, namely: “Best in Class”, “Best Producer” and “Supreme Pie Champion 2019”, beating 886 other competitors 5 at the contest in Melton Mowbray, Leicestershire 6 .

The leading chef, Richard Corrigan 7 , has blasted this butternut squash thing “a disgrace”. And, surely, the opinion of this Michelin-starred chef should be honoured and respected when he calls it a “pie in the sky”. All sane gastronomes will be relieved when he promises to make his “pig’s feet and black pudding and Swede pie” the next prize winner. 8

That’ll show those lily-livered lentil lovers!

While being interviewed by the Telegraph 9 , this bastion of butchery, who has proved his credentials as an arbiter of taste by having cooked for the Queen not once, but twice – showed how deeply affected he was by this culinary onslaught by uttering: “Please, please I’m going to cry.”

And, in support of the moderate and fair majority of people, he reminded us all of what proper food should be: “Pies are supposed to be filled with the most delicious morsels of steak and liver and kidney, with the jelly and little pieces of fat in the middle delicately dripping onto your tongue.

As though we’ve not had enough of populist nonsense – what with Brexiteers bandying around such outdated words like “democracy” and “national pride”. But to now have this travesty inflicted upon our already bowed and bruised heads by…one can hardly bear to say the word…v e g a n s.

As Chef Corrigan explains: “The oldest culinary art form left in the world and the vegans have taken it away. It’s a disgrace…The millennials have taken over…We should all just retire now.”

Matthew O’Callaghan, chairman of the 2019 British Pie Awards, appears to have slipped from the comforting embrace of omnivore common sense when he claims: “This year’s Supreme Champion was outstanding and well deserving of the accolade. From its very appearance on the judging tray you knew it was going to do well and it didn’t disappoint when it was opened and tasted. This pie isn’t just for vegans, it’s a pie for everybody. With this award we can truly say that veganism is now entering the mainstream of British food.” 5

The scale of the challenge ahead from marauding lettuce-lovers should not daunt the still-virtuous veganphobic nation of true meat-eaters.

Even as the faceless hordes of herbivores lay siege to the once great nation and its noble gastronomic traditions, I am reminded of John of Gaunt’s spirit-raising words of encouragement, as he lay on his death bed in Act One of Shakespeare’s Richard II:

“This royal throne of kings, this scepter’d isle,
This earth of majesty, this seat of Mars,
This other Eden, demi-paradise,
This fortress built by Nature for herself
Against infection and the hand of war,
This happy breed of men, this little world,
This precious stone set in the silver sea,
Which serves it in the office of a wall,
Or as a moat defensive to a house,
Against the envy of less happier lands,
This blessed plot, this earth, this realm, this England,
This nurse, this teeming womb of royal kings,
Fear’d by their breed and famous by their birth,
Renowned for their deeds as far from home,
For Christian service and true chivalry,
As is the sepulchre in stubborn Jewry,
Of the world’s ransom, blessed Mary’s Son,
This land of such dear souls, this dear dear land,
Dear for her reputation through the world,
Is now leased out, I die pronouncing it,
Like to a tenement or pelting farm:
England, bound in with the triumphant sea
Whose rocky shore beats back the envious siege
Of watery Neptune, is now bound in with shame,
With inky blots and rotten parchment bonds:
That England, that was wont to conquer others,
Hath made a shameful conquest of itself.
Ah, would the scandal vanish with my life,
How happy then were my ensuing death!”

He may as well have been making this speech now, just as the lights are being extinguished in the finest meat and two veg eateries across our nation…

Final thought

Now, I’m not claiming that the likes of Thorner’s vegan pie or Greggs’ vegan sausage roll are either ideal foods for optimal human health or what I would recommend as part of a WFPB diet – except maybe the very occasional “treat” to remind ourselves of what too much added salt and oil taste like. I mean, the name of my Greggs’ blog (“Greggs’ Vegan Sausage Rolls – Why Veganism Can Fail“) was not chosen for no reason!

However, the amount of venom spewed out by newspaper readers is somewhat over-the-top by anyone’s standards.

Such as some of those following the Telegraph article  9 :

  • What’s the problem? They are made out of Vegans, aren’t they?”
  • “I can’t eat grass; animals can. I can eat animals.”
  • “Sorry, vegans. I only eat fatty pork pies, or pies with succulent chunks of cow floating in ale and gravy.”
  • You can keep your veggie rubbish.”
  • “I’m with Mr Corrigan: if it’s “vegan” you can’t call it a pie. That would be an insult to the centuries of gloriously rich, meaty, aromatic, mouth-watering pies that have gone before. A non-meat snack for trendy neurotics, perhaps?”
  • Meat is good and the majority of people will not succumb to this utter BS.”
  • Also why salad lovers liberally apply dressing: because chomping on grass is not for humans it’s for ruminants. Cows eat the grass, we eat the cows, that’s the way the food chain works.”
  • You do know you’re made of meat right? And when your vegan body starts to starve you start to digest it to survive. That will be the least of your problems.”

And if you think that trying to educate people about veganism is a bit of a challenge, try espousing the virtues of a non-SOS WFPB diet. You’d lose count of the toys thrown out of prams.


  1. Greggs’ Vegan Sausage Rolls – Why Veganism Can Fail []
  2. The Guardian: Success of vegan sausage roll gives Greggs surge in sales []
  3. Jon Thorner’s of Somerset []
  4. British Pie Awards – 2019 []
  5. LeicestershireLive: Vegan pie named ‘supreme champion’ at British Pie Awards – for the first time ever [] []
  6. Location of Melton Mowbray, Leicestershire. []
  7. Wikipedia: Richard Corrigan. []
  8. Richard Corrigan: Facebook. []
  9. Telegraph. 8 March 2019: British Pie Awards 2019: Vegan pie is crowned Supreme Champion . [] []

Vitamin B12 Status in Spanish Veggies & Vegans

A previous blog 1 looked at a pre-published study on vitamin B12 status in Spanish vegetarians and vegans. Because there are very few reports on plant-based dietary patterns in Spain, this blog will look at the same study 2 in more detail, now that it has been published in its final form. While looking at B12 status amongst lacto-ovo vegetarians (LOV) and vegans (VN), it became clear that establishing true levels of this vitamin is a much more complex matter than most people realise. And, since side-effects of B12 deficiency are so nasty, this might be a blog worth reading – especially if you’re a plant-eater.

Thus, before looking at this study, it’s worth going into a bit more detail about vitamin B12.

Why is B12 status so important?

In normal healthy bodies, vitamin B12 (cobalamin) is readily absorbed in the distal ileum (the last part of the small intestine). However, in order for it to be absorbed, it must combine with a vital substance called intrinsic factor, which is a glycoprotein secreted by parietal cells of the gastric mucosa within the stomach. Without intrinsic factor, vitamin B12 will simply pass through the body and get excreted in stools.

Both vitamin B12 and vitamin B9 (folate) are necessary for the formation and maturation of red blood cells (erythrocytes) and the synthesis of DNA – the genetic material of cells. Vitamin B12 is also necessary for normal nerve function.

Since B12 is so essential for the formation of mature blood cells, any deficiency of this vitamin can result in anaemia, causing the body’s cells to receive insufficient oxygen from the haemoglobin within the red blood cells.

There are actually two forms of anaemia related to B12 deficiency and both are referred to as macrocytic anaemias 3 which can be either megaloblastic or pernicious anaemia:

Megaloblastic anaemia

This is characterised by abnormally large red blood cells (macrocytes) and abnormal white blood cells. It may not develop until 3-5 years after the deficiency starts. This is because around 3-5 years worth of B12 can be stored in the liver – so long as you’re an adult who has already been able to store sufficient quantities. No other B vitamin (or vitamin C) can be stored in the body like this, since they are all water-soluble (including B12) and are generally flushed out of the body if there is excess within the diet. On the other hand, the fat-based vitamins (A, E, D and K) can be stored in fat tissues as well as the liver. This means that daily intakes of the water-based vitamins (vitamins C, B1, B2, B3, B5, B6, B7, B9 and B12) is really important for maintenance of optimal health.

Megaloblastic anaemia is where insufficient B12 (or folate) is available to allow the normal DNA synthesis of red blood cells. It can be due to a number of causes, including:

  • insufficient B12 in the diet
  • overgrowth of bacteria in part of the small intestine
  • impaired absorption (malabsorption disorders such as coeliac disease or certain pancreatic disorders)
  • inflammatory bowel disease (IBD)
  • fish tapeworm infection
  • AIDS
  • surgery that removes the part of the small intestine where vitamin B12 is absorbed
  • drugs such as antacids and metformin (used to treat diabetes)
  • repeated exposure to nitrous oxide (laughing gas)
  • lack of intrinsic factor (see pernicious anaemia below)
  • decreased stomach acidity (common among older people)

As we age, our ability to absorb B12 decreases. This happens irrespective of dietary habits, but obviously there’s a bigger threat of deficiency (in all ages) for those who don’t eat animal products- the major source of B12. Bacteria in the soil and elsewhere produce B12. Animals don’t actually produce it themselves. If we still drank from pure streams and ate food we picked up from untreated soils, we’d get sufficient B12. However, with chlorinated water, pesticide-treated soils, and shrink-wrapped food, we either have to eat animal products or take supplements to ensure we get enough B12. There are plants that contain some of the vitamin (see below), but they are generally considered insufficient on their own to maintain healthy B12 levels.

Pernicious anaemia

Pernicious anaemia is a form of megaloblastic anemia where intrinsic factor is lacking. There may well be plenty of B12 in the diet, but if intrinsic factor is not present or, for some other reason, is not able to play its role in the the absorption of vitamin B12 from the small intestine into the bloodstream, then the B12 passes through and out of the body. This may be due to a number of reasons. For instance, abnormal antibodies, produced by an overactive immune system, may attack and destroy the parietal cells in the stomach that produce intrinsic factor, resulting in an autoimmune reaction called autoimmune metaplastic atrophic gastritis. Alternatively, intrinsic factor may be lacking because the part of the stomach where intrinsic factor is produced has been surgically removed.

Symptoms of B12 deficiency

Anaemia caused by vitamin B12 deficiency develops gradually. This allows the body to adapt to some extent, but this can mean that symptoms are mild while the anaemia is actually very severe.

Mild anemia symptoms can include:

  • paleness
  • weakness
  • fatigue

More serious anaemia symptoms can include:

  • shortness of breath
  • dizziness
  • rapid heart rate
  • spleen and liver enlargement

Pernicious anaemia in younger adults (due to lack of intrinsic factor) is more likely to result in the development of stomach and other gastrointestinal cancers.

B12 deficiency and nerve damage

Because B12 plays a significant role in the synthesis and maintenance of myelin4 , prolonged deficiency can result in damage to the central (CNS) and peripheral (PNS) nervous systems. In relation to CNS damage, white matter of the spinal cord and brain can suffer, resulting in such conditions as subacute combined degeneration (SCD) 5 and optic nerve atrophy. PNS issues are commonly manifested as nerve damage to the legs and arms, with the legs usually being affected earlier and more often than the arms. Symptoms include:

  • tingling in the feet and hands
  • loss of sensation in the legs, feet, and hands
  • weakness in arms and legs
  • loss of position sense – that is, people can’t tell so well where their arms and legs are and fail to feel vibrations
  • mild to moderate muscle weakness
  • loss of normal reflexes
  • difficulty in walking

In addition to the above neurological effects, some people can also become confused, irritable, and mildly depressed.

Advanced vitamin B12 deficiency may lead to delirium, paranoia and impaired mental function, including dementia.

Diagnosis of B12 deficiency

Diagnosis is via:

  • blood tests
  • the Schilling test (often in younger patients)
  • endoscopy
Blood tests

Routine serum blood tests can often show a suspected B12 deficiency if large red blood cells are detected. Since folate (vitamin B9) is also responsible for red blood cell synthesis, a possible B9 deficiency would normally also be investigated.

B12 deficiency can also be suspected if people complain of the typical symptoms associated with nerve damage, such as tingling or loss of sensation. If the deficiency is suspected, the level of vitamin B12 in the blood is measured.

Additionally, serum gastrin 6  levels or autoantibodies 7  to intrinsic factor may be measured.

Schilling test

The Schilling test involves the patient being given two doses of B12. The first is ‘labelled’ with a small amount of a radioactive substance and is then taken by mouth. The second is an injection one hour later of a larger amount of B12 that is not radioactively labelled, which is used in order to prevent any of the labelled B12 from binding to B12-depleted tissues.

After the injection is given, the amount of labelled B12 (that which had been taken orally) is measured by testing the urine to determine whether the body absorbed a normal (digested, rather than injected) amount of the vitamin.

If this normal amount has not been absorbed (revealed by a high amount being found in the urine), then the deficiency is confirmed. The same test is then repeated. This time, people are given intrinsic factor with the B12 taken by mouth. If intrinsic factor enables the body to absorb more of the vitamin, then it’s confirmed that the deficiency is caused by a lack of intrinsic factor, and the diagnosis of pernicious anemia can be made. If the B12 is still not absorbed, further tests are undertaken to check for potential problems with pancreatic enzymes or bacterial abnormalities.

More detail on this test can be found here 8 .


Endoscopy is the use of a flexible viewing tube to directly examine internal structures. It may be done to check for destruction of the parietal stomach cells that produce intrinsic factor.

If vitamin B12 deficiency is confirmed in an older person, it’s unlikely that either Schilling or endoscopy will be used. This is because the cause is likely to be the usual age-related reduction in stomach acidity, and is usually not serious. However, in a younger person, other tests, including other blood tests, Schilling test and endoscopy are likely to be used in order to establish intrinsic factor status.

Folate, B12 deficiency & plant-based diets

It’s important to note that high folate (vitamin B9) levels can give a false negative for B12 deficiency. That is, high levels of folate in the blood sample can make it look like there’s no B12 deficiency. This is because the constant supply of folate allows the red blood cells to appear normal in size, while the other serious neurological damage of B12 deficiency can go unnoticed, in spite of the person having regular blood tests for B12 deficiency.

Of course, those people most likely to have a B12 deficiency while having high dietary folate intake are those eating a plant-based diet – given that there’s so much folate in plant foods. This is why B12 supplementation is so important.

Treatments for B12 deficiency

For less advanced deficiency, B12 supplements generally do the trick; however, if people already have nerve damage, or they have pernicious anaemia (for instance, caused by having had the part of the stomach removed which produced intrinsic factor), then the B12 is normally given by injections into a muscle for defined periods so long as the disorder is uncorrected.

Since the B12 in supplements is easier to absorb than that in meat, older people with deficiency can benefit from taking B12 supplements.

In most people with mild to moderate anaemia, there is a normalisation in around 6 weeks of treatment with high doses of B12 supplements. However, in severe cases due to nerve damage or loss of ability to produce intrinsic factor, the treatment by B12 injection could last for the rest of their lives.

Unfortunately, in those with dementia resulting from B12 deficiency (mostly older people), mental function would not be expected to improve after treatment.

How much B12 should I supplement?

I covered this subject in some detail in a previous blog 9 , which I suggest you take a look at if you are unsure about how often and how much B12 you should be supplementing.

Non-animal foods containing vitamin B12

Several mushroom species contain some B12, including:

  • shiitake (Lentinula edodes)
  • black trumpet (Craterellus cornucopioides), and
  • golden chanterelle (Cantharellus cibarius)

Certain algae and cyanobacteria 10 such as:

  • chlorella 11 , and
  • spirulina (Arthrospira platensis12

The above are some of the foods normally used to produce B12 supplements for veggies and vegans.

Animal foods containing B12

Animal sources highest in vitamin B12 include meats (especially beef, pork, liver, and other organ meats), eggs, fortified cereals, milk, clams, oysters, salmon, and tuna.

It’s been reported that B12 deficiency exists much more widely in omnivore populations than one might imagine, since modern animal rearing practices are causing a reduction in the levels of B12 in meat. This can be seen particularly clearly, for instance, in the need to given cobalt supplements to cattle and sheep because of the reduced levels of cobalt in modern cultivated soils (B12 is called cobalamin because it contains a cobalt atom) 13 .

The Spanish study 2

The 49 lacto-ovo vegetarians and 54 vegans in the study filled out a Food Frequency Questionnaire (FFQ), and were tested to establish the following classical and functional markers (explanation of all terms in green can be seen by holding the cursor over the adjacent footnote number):

  • serum B12 14
  • erythrocyte folate (vitamin B9) 15
  • homocysteine (Hcy) 16 / hyperhomocysteinaemia (HHcy) 17  
  • methylmalonic acid (MMA) 18
  • mean corpuscular haemoglobin (MCH) 19
  • mean corpuscular erythrocyte volume (MCV) 20

In broad terms, two parts of this study are of particular interest: firstly, the difficulties involved in accurately diagnosing B12 deficiency (and the suggested additional tests by which this can be more accurately diagnosed) and, secondly, to see if there was any pattern of B12 deficiency between the two groups – lacto-ovo-vegetarian (LOV) and vegan (VN).

1. Difficulties in diagnosing B12 deficiency

In order to understand the potential difficulties involved in diagnosing B12 deficiency, it’s useful to understand the vital processes B12 undergoes within the body, and this will involve knowing about two biological cycles: the methionine cycle and the folate cycle, both of which are essential for DNA and RNA synthesis, the production of red blood cells (erythropoiesis) and the production of neurotransmitters. 21 22

Vitamin B12 acts as a cofactor 23 of the enzymes methionine synthase 24 , which acts in the conversion of homocysteine (Hcy) to methionine, and methylmalonyl-CoA mutase 25 , that produces succinyl-CoA from methylmalonyl-CoA, the active form of methylmalonic acid (MMA)18 .

The above reactions are involved in the methionine cycle 26 and the folate cycle 27 , both essential for DNA and RNA synthesis, erythropoiesis and the production of neurotransmitters.

The folate cycle is so important to the methionine cycle (also called the methylation cycle) that it’s often included in descriptions and diagrams of the methionine cycle. The following diagram should give you an idea of how interlinked and complex these cycles are.

Problems with Serum B12 tests

As mentioned above, testing levels of serum B12 is probably the most widely used means of assessing deficiency. However, a major problem is that it can appear perfectly normal whilst, at the same time. functional deficiency still lurks unseen beneath the surface. The long latency period of B12 deficiency showing up in the blood serum can regularly produce both false positives and false negatives – that is, appearing to have a deficiency but not having one, or not appearing to have a deficiency but actually having one. 28

Folate (vitamin B9) & B12

Since it’s known both that high levels of folate can mask B12 deficiency and that low levels of folate can account for hyperhomocysteinaemia (HHcy)17 , it follows that testing for folate levels would be rather useful. By establishing that folate levels are high (as they are likely to be in most plant-eaters – unless, of course, they’re living on a diet of doughnuts and chips!) , it would be possible to quickly discard folate deficiency as being responsible for HHcy or the presence of megaloblastic anaemia. 29

Homocysteine & B12

Testing for homocysteine (Hcy) levels – a more specific marker of functional vitamin B12 deficiency – would be a useful additional test. This is because Hcy levels rise in the presence of cellular B12 deficiency. So, is that sorted, then? Well, not quite. Another problem arises – namely, that Hcy levels can also be raised with deficiencies of vitamins B9 (folate) or B6 (pyridoxine) as well as by diets rich in methionine 30 . So back to the drawing board.

Methylmalonic acid (MMA) & B12

So, what about testing for MMA levels? This represents probably the most specific marker for vitamin B12 deficiency, since it’s independent of folate and vitamin B6 status. MMA levels increase when there’s a B12 deficiency, and this happens even before there are any obvious clinical symptoms of the deficiency.

The more the merrier

So, the researchers in this study suggest that when testing for B12 deficiency, relying on just one single standard marker of deficiency is to be avoided. Instead, several markers should be used – levels of serum B12/B9, Hcy and MMA 31 .

2. B12 status of Spanish lacto-ovo-vegetarians & vegans

Finally, we come to the findings of this study:

  • the overall prevalence of clinical vitamin B12 deficiency was very low in the individuals tested
  • when serum B12 levels alone were tested, there was no indication of B12 deficiency in either diet group

Various B12 markers

However, when MMA was measured, some subclinical deficiencies were detected, particularly in the non-users of vitamin B12 supplements, with no significant differences between VN and LOV. With elevated MMA being detected in more than 10 % of the study subjects, it’s clear that using this marker to detect subclinical deficiencies is a pretty good idea.

  • although macrocytosis (enlarged red blood cells) was observed in several participants, no clear relationship to any biomarkers of vitamin B12 deficiency could be found
  • HHcy was found in more than 30 % of the subjects

They recommend that both MMA and Hcy (together with serum B12) should be used since each of these biomarkers gives information about the actions of B12 in different metabolic pathways. For instance, the metabolic reactions leading to the production of MMA and Hcy require different cobalamin forms:

  • methylcobalamin acts in the Hcy pathway
  • adenosylcobalamin acts in the formation of succinyl-CoA

The latter occur in different cell compartments:

  • the methionine and folate cycles occur in the cell’s cytoplasm 32
  • the synthesis of succinyl-CoA (SCS) 33  occurs in the mitochondria34

When B12 status was assessed with serum vitamin B12, MMA and Hcy simultaneously, the proportion of subjects with values out of range of at least one of the biomarkers was remarkably higher than the proportion detected by using only serum B12.

Most of the hyperhomocysteinaemic individuals presented mild HHcy (16–30 µmol/l) while only three volunteers had moderate HHcy (31–100 µmol/l).

Hcy variation in veggies from different European countries

Interestingly, this study comments on the fact that there’s great variability in the B12 values obtained in vegetarians from different European countries:

  • German vegetarians had lower Hcy levels 35
  • Slovak and Austrian vegetarians had higher Hcy levels 36

In the current study, Hcy was higher in LOV than in VN, which contrasted with other studies 37 .

High folate levels

Erythrocyte folate levels were high in all participants, with more than 50 % surpassing the suggested 38 cut-off for high erythrocyte folate (1360 nmol/l). This is in line with other research 39 that found higher folate intakes in plant-eaters than in omnivores.

Methionine & Hcy/HHcy

With folate repletion and under similar B12 levels, it was observed that LOV had higher levels of both Hcy and HHcy than VN. The researchers said this might be due to the fact that LOV consume more protein and, thus, more methionine, being that both dairy and egg are higher in methionine than plant foods. By increasing blood levels of Hcy, high methionine levels are linked to increased risk of heart disease, tumour growth, brain damage and even death.

The importance of supplementation

Various studies 37 have reported lower B12 levels in vegans, but this was not observed in the present study. The reason for this is thought to be that the members of both Spanish groups had a high and extended use of cobalamin (B12) supplements, with B12 supplement users exhibiting higher serum B12 and erythrocyte folate levels (as well as lower MMA and Hcy) than non-users. This underlines the importance of supplementation for vegans and lacto-ovo vegetarians.

These results are, of course, consistent with previous studies that recommend intake of B12 in supplement form. The reason generally given – which seems perfectly fair – is that it’s difficult for plant-eaters to achieve consistent and sufficient B12 levels without taking B12 supplements. The intake of fortified food items is not enough, of itself, to provide the required doses of the vitamin.40 41

Supplementation, diet or socioeconomic variation?

In recent studies on vegetarian Indians 42 43 , a prevalence of B12 deficiency was found in around 70 % of those tested, with more than 50 % of the subjects also presenting HHcy.

An explanation for this variation between results from Spain and India may be explained by differences in both diet composition and socioeconomic status. 44 

However, even in studies of B12 status in European countries (where one would expect vegetarians to have similar socioeconomic status and diet composition as found in Spain), similar differences (that is, less B12 deficiency in Spanish vegetarians) was seen in Germany, the Netherlands and the UK. 45

Thus, the researchers maintain that the sufficient B12 status observed in both Spanish groups (LOV and VN) can be mainly accounted for by the extended use of cobalamin supplements in the Spanish participants compared with the lower amount of such supplementation reported in other European studies.

Spanish plant milks are not fortified

Having spent a significant time at our mountain retreat in Spain, it has always interested me that the Spanish do not fortify their plant milks – unlike the UK and elsewhere in Europe. This is a very good reason why any veggie living (or spending extended periods) in Spain should not rely on plant milks for their B12. Indeed, the current study emphasises that such milks had no influence on the analysed biomarkers in this research, being that these milks are not B12-fortified.

Final thoughts

Two limitations of this study were, firstly, that they didn’t add an additional omnivore group for comparison, since this would have shown whether and by how much these groups (LOV and VN) differed from the general meat-eating Spanish population and, secondly, this was a small sample (103 individuals) from which to generalise to the whole Spanish LOV and VN population – of which veggies are thought 46 to comprise around 1.5%.

What would have been interesting, in addition, would have been to include a WFPB dietary group. Naturally, this is something that would prove very difficult in almost any country (perhaps excluding certain ‘enlightened’ populations within the US), since the number of people eating a WFPB diet is still very low.

The report did not consider the influence of any potential genetic polymorphisms 47 that might be involved in the B12 and folate routes. Perhaps future B12 studies could look at this, as well as include a larger number of subjects and include both omnivores and those eating a WFPB diet.

In any case, the take-home message is that anyone eating a plant-based diet needs to take B12 supplementation. It’s a cheap and highly effective way of avoiding health conditions that would undo some of the wonderful work achieved by eating this way.

References & Notes

  1. B12 Supplements Are Efficient But Caution With Folic Acid []
  2. J Nutr Sci. 2019 Feb 26;8:e7. doi: 10.1017/jns.2019.2. eCollection 2019. Vitamin B12 and folate status in Spanish lacto-ovo vegetarians and vegans. Gallego-Narbón A, Zapatera B, Barrios L, Vaquero MP. [] []
  3. The term macrocytic is from Greek words meaning “large cell”. A macrocytic class of anaemia is an anaemia (defined as blood with an insufficient concentration of haemoglobin) in which the red blood cells (erythrocytes) are larger than their normal volume. []
  4. Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances. This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells. []
  5. Subacute combined degeneration (SCD) is characterised by symmetric dysesthesia, disturbance of position sense and spastic paraparesis or tetraparesis. []
  6. Gastrin is a hormone which stimulates secretion of gastric juice and is secreted into the bloodstream by the stomach wall in response to the presence of food. []
  7. An autoantibody is antibody produced by in response to a constituent of its own tissues. []
  8. Schilling Test Kamleshun Ramphul; Stephanie G. Mejias. Statpearls. []
  9. Vegan Society Veg-1: Does It Contain Enough B12? []
  10. Cyanobacteria are a division of microorganisms related to bacteria but which are capable of photosynthesis. They are prokaryotic and represent the earliest known form of life on the earth. []
  11. a genus of single-celled green algae belonging to the division Chlorophyta. []
  12. Spirulina is a biomass of cyanobacteria (blue-green algae) from the two species Arthrospira platensis and A. maxima. It can be consumed by humans and other animals. Arthrospira is cultivated worldwide and is used as a dietary supplement or whole food, being also used as a feed supplement in the aquaculture, aquarium, and poultry industries. []
  13. J Dairy Sci. 1979 Aug;62(8):1195-206. Trace element deficiencies and fertility in ruminants: a review. Hidiroglou M. []
  14. In blood, serum is the liquid part but without the clotting factors (mainly fibrinogens). The liquid part with the clotting factors is the plasma. Serum still includes all the other proteins not used in blood clotting, along with all the electrolytes, antibodies, antigens, hormones, and any exogenous substances. []
  15. Red blood cell (erythrocyte) folate concentrations respond slowly to changes in dietary folate intake since the erythrocytes, which have a 120-day lifespan, accumulate folate only during the production of new red blood cells (erythropoiesis). Red blood cell folate concentrations are useful as indicators of long-term folate status. []
  16. Homocysteine (an intermediate in the metabolism of the amino acids methionine and cysteine) is a common amino acid in your blood. You get it mostly from eating meat. High levels of it are linked to early development of heart disease. and is associated with low levels of vitamins B6, B12, and folate, as well as with renal disease. []
  17. Hyperhomocysteinaemia is a medical condition characterised by an abnormally high level of homocysteine in the blood, conventionally described as being above 15 µmol/L. Hyperhomocysteinaemia is typically managed with vitamin B6, vitamin B9 and vitamin B12 supplementation.  Hyperhomocysteinaemia promotes the formation of active oxygen species and the release of inflammatory mediators, and therefore it is considered a risk factor for cardiovascular disease (CVD). [] []
  18. Methylmalonic acid (MMA) is a substance produced in very small amounts and is necessary for human metabolism and energy production. The measurement of elevated amounts of methylmalonic acid in the blood or urine serves as a sensitive and early indicator of vitamin B12 deficiency. [] []
  19. Mean corpuscular haemoglobin is the average mass of haemoglobin per red blood cell in a sample of blood. High MCH levels are commonly a sign of the macrocytic anaemia seen in B12 or folate deficiency. []
  20. Mean corpuscular volume is a measure of the average volume of a red blood corpuscle. The measure is attained by multiplying a volume of blood by the proportion of blood that is cellular, and dividing that product by the number of erythrocytes in that volume. High MCV implies the red blood cells are larger than normal (i.e. macrocytic) and is a test of B12 and folate deficiency. []
  21. Krishnaswamy K & Madhavan Nair K (2001) Importance of folate in human nutrition. Br J Nutr 85, Suppl. 2, S115–S124. []
  22. Kapoor A, Baig M, Tunio SA, et al. (2017) Neuropsychiatric and neurological problems among vitamin B12 deficient young vegetarians. Neurosciences (Riyadh) 22, 228–232. []
  23. A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme’s activity. Cofactors can be considered “helper molecules” that assist in biochemical transformations. []
  24. Methionine is an essential amino acid that has to be derived from our diet. Methionine synthase is responsible for the regeneration of methionine from homocysteine. []
  25. Methylmalonyl-CoA mutase (MCM) is a protein that in humans is encoded by the MUT gene. This vitamin B12-dependent enzyme catalyses the isomerisation of methylmalonyl-CoA to succinyl-CoA in humans. []
  26. In the methionine cycle, methionine (a sulphur-containing amino acid which enters the body through dietary proteins) is used in forming proteins in the body. In the methionine cycle, methionine acts as the precursor of the sulphur-containing amino acids homocysteine, cysteine, and taurine. Taurine is one of the few amino acids not used in protein synthesis, and is thus usually referred to as a “nonessential” amino acid, or more generously as a “conditionally essential” amino acid. []
  27. Within the folate cycle, folate coenzymes are responsible for the one-carbon unit transfer in intermediary metabolism and are required for several reactions in key metabolic processes, for example of purine, pyrimidine and methionine synthesis, and glycine and serine metabolism. []
  28. Klee GG (2000) Cobalamin and folate evaluation: measurement of methylmalonic acid and homocysteine vs vitamin B12 and folate. Clin Chem 46, 1277–1283. []
  29. Krajcovicova-Kudlackova M, Blazicek P, Kopcova J, et al. (2000) Homocysteine levels in vegetarians versus omnivores. Ann Nutr Metab 44, 135–138. []
  30. Kumar A, Palfrey HA, Pathak R, et al. (2017) The metabolism and significance of homocysteine in nutrition and health. Nutr Metab (Lond) 14, 78. []
  31. Yetley EA, Pfeiffer CM, Phinney KW, et al. (2011) Biomarkers of vitamin B12 status in NHANES: a roundtable summary. Am J Clin Nutr 94, 313S–321S. []
  32. Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It’s mainly composed of water, salts, and proteins. All the organelles, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm within eukaryotic cells. Organelles are the organised or specialised structures within a living cell. Eukaryotic cells are cells that contain a nucleus and organelles, enclosed by a plasma membrane. Humans are composed of eukaryotic cells and are thus grouped into the biological domain Eukaryota. Eukaryotic cells are larger and more complex than prokaryotic cells, which are found in Archaea and Bacteria, the other two domains of life. []
  33. Succinyl-CoA or SCS facilitates the flux of molecules into other metabolic pathways by controlling the interconversion between succinyl CoA and succinate. This is important because succinyl CoA is an intermediate necessary for porphyrin, haem, and ketone body biosynthesis. It’s a necessary part of the energy-producing Krebs or citric acid cycle. []
  34. The mitochondria is an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur – the “powerhouses” of energy production. []
  35. Waldmann A, Koschizke JW, Leitzmann C, et al. (2004) Homocysteine and cobalamin status in German vegans. Public Health Nutr 7, 467–472. []
  36. Majchrzak D, Singer I, Manner M, et al. (2006) B-vitamin status and concentrations of homocysteine in Austrian omnivores, vegetarians and vegans. Ann Nutr Metab 50, 485–491. []
  37. Elmadfa I & Singer I (2009) Vitamin B12 and homocysteine status among vegetarians: a global perspective. Am J Clin Nutr 89, 1693S–1698S. [] []
  38. Colapinto CK, O’Connor DL & Tremblay MS (2011) Folate status of the population in the Canadian Health Measures Survey. CMAJ 183, E100–E106. []
  39. Schüpbach R, Wegmüller R, Berguerand C, et al. (2017) Micronutrient status and intake in omnivores, vegetarians and vegans in Switzerland. Eur J Nutr 56, 283–293. []
  40. Gilsing AM, Crowe FL, Lloyd-Wright Z, et al. (2010) Serum concentrations of vitamin B12 and folate in British male omnivores, vegetarians and vegans: results from a cross-sectional analysis of the EPIC-Oxford cohort study. Eur J Clin Nutr 64, 933–939. []
  41. Pawlak R, Lester SE & Babatunde T (2014) The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature. Eur J Clin Nutr 68, 541–548. []
  42. Naik S, Mahalle N & Bhide V (2018) Identification of vitamin B12 deficiency in vegetarian Indians. Br J Nutr 119, 629–635. []
  43. Yajnik CS, Deshpande SS, Lubree HG, et al. (2006) Vitamin B12 deficiency and hyperhomocysteinemia in rural and urban Indians. J Assoc Physicians India 54, 775–782. []
  44. Menal-Puey S & Marques-Lopes I (2017) Development of a food guide for the vegetarians of Spain. J Acad Nutr Diet 117, 1509–1516. []
  45. Herrmann W, Schorr H, Obeid R, et al. (2003) Vitamin B12 status, particularly holotranscobalamin II and methylmalonic acid concentrations, and hyperhomocysteinemia in vegetarians. Am J Clin Nutr 78, 131–136. []
  46. AECOSAN (2011) National Survey of Dietary Intake (2009–2010). Results on Consumption Data. Madrid: Spanish Agency for Consumer Affairs, Food Safety and Nutrition Government of Spain. []
  47. Polymorphisms are the occurrence of different forms among the members of a population or colony, or in the life cycle of an individual organism. []

Flaxseeds / Linseeds – Lignan Heaven

There are a wide number of reasons why it’s a pretty good idea to add flaxseeds to your food shopping list, whether or not you’re eating a plant-based diet. These little seeds are a powerhouse of goodness. If, as a result of reading this blog, you’re encouraged to include them in your daily diet, then I’ll be pretty confident that, in a small way, I’ve helped you towards a longer and healthier life.

Is flaxseed the same as linseed?

If you enter either word in Wikipedia, you get exactly the same page. I guess this indicates that they are, to all intents and purposes, the same thing – members of the plant family Linaceae and the genus Linum. Whilst there are variations within the genus, the only major difference you’ll notice is that the seeds can be either brown or golden (yellow) in colour.

Although fibrous parts of the flax plant are used for various purposes (including making clothing), and you’ll know about the uses of linseed oil (including protecting cricket bats), we’ll just concentrate on the linseed/flaxseeds themselves, which will be herein referred to as flaxseeds for the sake of brevity. By the way, my advice is to avoid consuming any the the oil prepared from flaxseeds, for the same reason as all oils are to be avoided 1 . Instead, just stick to the seeds.

Why do flaxseeds need to be ground?

Unlike most seeds, the outer protective shell of each tiny flaxseed is so tough that eating them whole will mean they ‘cut out the middle man’ and end up, intact, in the toilet bowl. By grinding them, all the wonderful goodness is released. I go into this in a bit more detail later.

What’s the nutritional value of flaxseeds?

Most flaxseeds have an almost identical nutritional profile, with the same number of omega-3 fatty acids. This makes them a really important part of any plant-based diet. There is, however, one variant of yellow flax (solin, usually under the trade name “Linola”) which is very low in omega-3 fatty acids. Fibre, protein, and fat profiles are excellent.

You’ll see from the nutritional value chart 2 that there are also plenty of vitamins and minerals in flaxseeds. But the good news doesn’t end there. Of all the individual so-called ‘super foods’ that you could think of, flaxseeds will be right up there at the top. The lignan content is just one weapon in their disease-fighting armoury. Essential fatty acids (ALA and AA) and fibre content are also remarkably high. To give you an idea of just how amazing the bundle of compounds in flaxseeds really are, the following is a list of some of the health benefits that these amazing little fellas may offer:

  • lowering blood pressure 3 , hence:
    • helping to prevent heart attacks 4
    • helping to prevent strokes 5
  • fighting cancer
    • prostate cancer 6 7
    • breast cancer 8 9
  • lowering blood cholesterol levels 10
  • reducing blood triglyceride levels 11
  • reducing blood sugar levels/insulin resistance/diabetes risk 12 13 14
  • reducing inflammation 15 16
  • preventing/treating constipation 17
  • reducing body weight/BMI 18
  • preventing osteoporosis/bone loss 19 20
  • preventing arthritis 21
  • improving skin health/healing 22
  • reducing number of menstrual periods 23

Omega-3 & flaxseeds

As I’ve pointed out in previous blogs, flaxseeds 24 25  and chia seeds 26 (along with walnuts) are probably the best non-fish sources of omega-3’s for those eating a plant-based diet. The long-chain polyunsaturated fatty acid (LC-PUFA) ALA (alpha-linolenic acid) is an essential fatty acid which we need to get from our diet since the human body can’t synthesise it on its own. When sufficient ALA is provided in the diet, the body can use it to make the longer-chain PUFA’s, DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), both of which are essential for our health. 27

The following diagrams illustrate the high levels of omega-3 oils in flaxseeds:

What are lignans?

From the Latin for “wood”  (lign-) plus the chemical suffix”-an”, lignans found in plants are a form of micronutrient called polyphenols 28 . In order for the plant lignans29 to be used by the human body, they have to be metabolised by our gut bacteria into the mammalian lignans called enterodiol and enterolactone (known as enterolignans – from the Greek énteron meaning intestine). So, plant lignans can be described as “lignan precursors” for our human versions.

Lignans are one of the major classes of phytoestrogens30 – oestrogen-like chemicals (found in foods like beans, seeds and grains) that also act as antioxidants. You’ll hear some comments on the internet that phytoestrogens are dangerous because they bind to and block important oestrogen receptors; however, this does not appear to be the case, since there are two different forms of oestrogen receptor, and phytoestrogens do not block those to which oestrogen normally attaches. Additionally, evidence exists 31 that they can help prevent cardiovascular diseases, diabetes and cancer of the breast, brain, colon, liver, ovaries and skin. They also appear to reduce LDL (“bad”) cholesterol and aid weight loss. While phytoestrogens found in plants do not decrease male fertility, the xenoestrogens 32, which, in terms of diet, are found mainly in fish, have been shown to drastically lower sperm count and cause early puberty.

Whilst the above long list 33 of health benefits offered by flaxseeds is, of course, also partly attributable to the other essential fatty acids, minerals, vitamins and phytochemicals they contain, the lignan content is especially powerful. Trying to decide exactly what each individual compound does is a really tough task, and perhaps not always necessary. After all, the compounds do not exist in isolation within plants and neither do they work in isolation within our bodies. Trying to pinpoint active compounds is something that pharmaceutical companies love to do, since they can then bottle them and sell them at high price, even though they often don’t work as they did when the compound was in its natural position within the complex of the original plant.

We’ve looked at the issue of wholism vs reductionism in a previous blog 34 . So, whether the cardiovascular protection afforded by flaxseeds is x% due to the omega-3, y% due to the fibre, and z% due to the lignans is, as far as I’m concerned, a secondary matter to what the whole seed is capable of doing with all three elements, plus the others we know about and the many we still haven’t even identified. And this doesn’t even touch on the vast array of interactions between these elements and the likelihood that there will be some variation between the physiology of individual humans – particularly in relation to the microbiome (gut, urinary, oral, etc) that our diets and lifestyles have provided us with.

In terms of lignans, why are flaxseeds so remarkable?

The type of lignans found in flaxseeds are not the only dietary lignans – others include sesamin 35 , matairesinol 36 , pinoresinol 37 and lariciresinol 38 . The main lignan in flaxseeds (as well as in sunflower, sesame, and pumpkin seeds) has the unpronounceable name “secoisolariciresinol diglucoside” or SDG for short. Regardless of the source of SDG, once it’s ingested, it’s “…converted in the colon into active mammalian lignans, enterodiol, and enterolactone, which have shown promise in reducing growth of cancerous tumors, especially hormone‐sensitive ones such as those of the breast, endometrium, and prostate. Known for their hydrogen‐donating antioxidant activity as well as their ability to complex divalent transition metal cations, lignans are propitious to human health.” 39 .  All well and good, but the remarkable thing about flaxseeds isn’t that the lignans they contain are not found in other seeds, rather it’s because of the incredibly high lignan content these little seeds have. Indeed, you’ll see from the following chart 40 that they contain around 100 times more lignans than almost every other food, with sesame seeds being the closest with 7 times less.

Add to this the fact that Dr Greger claims 41 there are no bad side effects to normal flaxseed consumption 42 – unless, of course, you’re one of the very few who has a flaxseed allergy 43 – and you have as near to a super food as you’re likely to get.

One study compared the results of flaxseeds and flaxseed oil: “SDG [the major type of lignan in flaxseeds] is a potent angiogenic and antiapoptotic agent that may have a role in cardio protection in ischemic heart disease. In conclusion, flaxseed, FLC, and SDG, but not flaxseed oil, suppress atherosclerosis, and FLC [flax lignan complex] and SDG slow progression of atherosclerosis but have no effect on regression. Flaxseed oil suppresses oxygen radical production by white blood cells, prolongs bleeding time, and in higher doses suppresses serum levels of inflammatory mediators and does not lower serum lipids.” 44

No lignans in flaxseed oil

It’s important to note that when you extract pure oil from flaxseeds, the important phytoestrogen lignans are removed 45 . This is another reason why it’s important to consume the whole seed and to generally keep away from extracted flaxseed oil – unless, of course, you want to grease your cricket bat! This rule applies to all extracted oils, of course, as mentioned above.

Flaxseed proteins

The following is a sample of research reviewed within one study 46  showing some of the varied health benefits from the proteins within flaxseeds:

Fatty acids in flaxseeds

The following chart (from the same study as above) indicates the levels of the major fatty acids within flaxseeds:

Historical & recent medicinal uses of flaxseeds

The following charts (from the same source as above) indicate some of the distant historical and more recent uses of flaxseeds (in the latter case, from flaxseed oil):

Microbiome & lignans

The nature of your gut bacteria (the intestinal microbiome) will affect how much of the lignan goodness is absorbed and utilised by your body. As one authority states: “It is likely that individual differences in the metabolism of lignans, possibly due to gut microbes, influence the biological activities and health effects of these compounds.” 47 As is the case with so much nutrient metabolism and absorption, having a healthy got microbiome is so important, and, as was shown in an earlier blog 48 a varied plant-based diet (as opposed to a meat- or processed food-based diet) provides by far the healthiest environment for intestinal bacteria.

How much ground flaxseed should we have each day?

Dr Greger can answer this for us. In response to one of the above-mentioned studies, entitled “Flaxseed: A Miraculous Defence Against Some Critical Maladies,” 3 , he states:

Miraculous”? Well, certainly super healthy, which is why a tablespoon of ground flaxseeds every day gets its own spot on the Daily Dozen checklist 49  I created to help inspire you to incorporate some of the healthiest foods into your daily routine.” 50

You can get your daily tablespoon of ground flaxseeds in so many ways: from mixing it in with your morning muesli to using it as a thickener in soups, stews, etc.

Dr Greger, flaxseeds & lignans

Talking about Dr G, you’d be able to get an idea of just how important a subject is by counting the number of videos he does on that subject. The following are just his most popular of videos which discuss the evidence for the lasting force of lignans and flaxseeds:

    • Which Are Better: Chia Seeds or Flax Seeds? 51
    • Flaxseeds for Hypertension 52
    • Can Flaxseeds Help Prevent Breast Cancer? 53
    • Flaxseeds for Breast Pain 54
    • Flaxseeds & Breast Cancer Survival: Clinical Evidence 55
    • Flaxseeds & Breast Cancer Survival: Epidemiological Evidence 56
    • Flaxseeds & Breast Cancer Prevention 57
    • Just the Flax, Ma’am? 58
    • Flaxseeds vs. Prostate Cancer 59
    • Flaxseeds vs. Diabetes 60
    • Was It the Flaxseeds, Fat Restriction, or Both? 61
    • Flaxseeds for Sensitive Skin 62
    • Flaxseeds vs. Chia Seeds 63
    • Which Are Better: Chia Seeds or Flaxseeds? 64

Final thoughts

It’s hard to believe that such a humble little seed can do so much good, but the evidence is there to support the claims – and the studies I’ve listed are but a small drop in the ocean of the research showing the multifarious benefits. The fact is, that it’s simply hard to over-egg (vegan alternative, of course!) the case for including flaxseed within one’s diet – especially if you’re completely plant-based and just want to ensure you get additional omega-3, along with walnuts.

So, why not make it a regular habit to include at least a tablespoon of flaxseeds in your daily diet?

Perhaps the best way to go about this is to have a supply always at the ready. Buy them whole in bulk. Buying pre-ground flaxseeds is much more expensive and it’s probably best to consume them within not too long a period of time after grinding – and you never know how long the ground version has been sitting on the shop shelf. So, possibly best to grind them yourself in a small coffee grinder and then store a kg of the ground up flaxseeds in a sealed container. So easy to dip into when you want. I also tend to make a weekly supply of muesli in a large container, into which I add ground flaxseeds from my 1kg flaxseed container. Since a tablespoon of flaxseeds weighs around 7 grams, I usually add around 100 grams for the week. Give it a good shake and you’re pretty confident about getting your weekly supply just from the muesli alone.

If it’s any help (although I’m not promoting either company), I buy flaxseeds in bulk (20 x 500 gram bags) from a company called Grapetree 65 . They appear to be one of the cheapest sources.

Additionally, I use a basic (but very effective) coffee grinder called the Duronic CG300 Electric Coffee Grinder Mill 66 , available from Amazon for £29.99. Of course, any coffee grinder will do the job. Just make sure you don’t grind the seeds too much (or you’ll get flaxseed butter) or too little (or you’ll leave intact and indigestible seeds). I tend to grind until the sound of the seeds hitting the top of the grinder stops, then scoop out the ground seeds.

References & Notes

  1. Olive Oil Injures Endothelial Cells []
  2. United States Department of Agriculture. Agricultural Research Service. USDA Food Composition Databases: Flaxseeds. []
  3. Pak J Pharm Sci. 2013 Jan;26(1):199-208. Flaxseed – a miraculous defense against some critical maladies. Akhtar S, Ismail T, Riaz M. [] []
  4. Can J Cardiol. 2010 Nov; 26(9): 489–496.The cardiovascular effects of flaxseed and its omega-3 fatty acid, alpha-linolenic acid. Delfin Rodriguez-Leyva, MD, PhD, Chantal MC Bassett, PhD, Richelle McCullough, BSc, and Grant N Pierce, PhD. []
  5. Contemp Clin Trials. 2011 May 17. The effect of dietary flaxseed on improving symptoms of cardiovascular disease in patients with peripheral artery disease: rationale and design of the FLAX-PAD randomized controlled trial. Leyva DR, Zahradka P, Ramjiawan B, Guzman R, Aliani M, Pierce GN. []
  6. Cancer Epidemiol Biomarkers Prev. 2008 Dec; 17(12): 3577–3587. Flaxseed Supplementation (not Dietary Fat Restriction) Reduces Prostate Cancer Proliferation Rates in Men Presurgery. Wendy Demark-Wahnefried, et al. []
  7. J Med Food. 2013 Apr; 16(4): 357–360. Flaxseed-Derived Enterolactone Is Inversely Associated with Tumor Cell Proliferation in Men with Localized Prostate Cancer. Maria Azrad, et al. []
  8. L. U. Thompson, J. M. Chen, T. Li, K. Strasser-Weippl, P. E. Goss. Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer. Clin. Cancer Res. 2005 11(10):3828 – 3835 []
  9. Front Nutr. 2018; 5: 4. The Effect of Flaxseed in Breast Cancer: A Literature Review. Ana Calado, Pedro Miguel Neves, Teresa Santos, Paula Ravasco. []
  10. Nutr Metab (Lond). 2012; 9: 8. Flaxseed dietary fibers lower cholesterol and increase fecal fat excretion, but magnitude of effect depend on food type. Mette Kristensen, et al. []
  11. Rev Recent Clin Trials. 2015;10(1):61-7. Effect of flaxseed on blood lipid level in hyperlipidemic patients. Torkan M, Entezari MH, Siavash M. []
  12. J Res Med Sci. 2016; 21: 70. Published online 2016 Sep 1. The effect of flaxseed powder on insulin resistance indices and blood pressure in prediabetic individuals: A randomized controlled clinical trial Afrooz Javidi, et al. []
  13. Curr Pharm Des. 2016;22(2):141-4. Flaxseed and Diabetes. Prasad K, Dhar A. []
  14. Nutr Rev. 2018 Feb 1;76(2):125-139. Flaxseed supplementation on glucose control and insulin sensitivity: a systematic review and meta-analysis of 25 randomized, placebo-controlled trials. Mohammadi-Sartang M, Sohrabi Z, Barati-Boldaji R, Raeisi-Dehkordi H, Mazloom Z. []
  15. J Am Coll Nutr. 2017 Nov-Dec;36(8):646-653. Influence of Flaxseed Lignan Supplementation to Older Adults on Biochemical and Functional Outcome Measures of Inflammation. Di Y, et al. []
  16. ISRN Inflamm. 2013; 2013: 735158. Effect of L. usitatissimum (Flaxseed/Linseed) Fixed Oil against Distinct Phases of Inflammation. Gaurav Kaithwas, Dipak K. Majumdar. []
  17. Nutr Metab (Lond). 2018; 15: 36. A randomized trial of the effects of flaxseed to manage constipation, weight, glycemia, and lipids in constipated patients with type 2 diabetes. Noureddin Soltanian, Mohsen Janghorbani. []
  18. Obes Rev. 2017 Sep;18(9):1096-1107. The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials. Mohammadi-Sartang M, et al. []
  19. Bioorg Med Chem Lett. 2016 Apr 1;26(7):1760-1. Cyclolinopeptides, cyclic peptides from flaxseed with osteoclast differentiation inhibitory activity. Kaneda T, Yoshida H, Nakajima Y, Toishi M, Nugroho AE, Morita H. []
  20. Pak J Biol Sci. 2008 Jul 1;11(13):1696-701. Preventive effects of flaxseed and sesame oil on bone loss in ovariectomized rats. Boulbaroud S, Mesfioui A, Arfaoui A, Ouichou A, el-Hessni A. []
  21. Nutrients. 2016 Mar; 8(3): 136. Effect of Flaxseed Intervention on Inflammatory Marker C-Reactive Protein: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Guan-Yu Ren, et al. []
  22. Int J Biol Macromol. 2015 Jan;72:614-23. Flaxseed lignan wound healing formulation: characterization and in vivo therapeutic evaluation. Draganescu D, et al. []
  23. J Clin Endocrinol Metab. 1993 Nov;77(5):1215-9. Effect of flax seed ingestion on the menstrual cycle. Phipps WR, Martini MC, Lampe JW, Slavin JL, Kurzer MS. []
  24. Non-Fish Sources of Omega-3 []
  25. Omega 3 Supplements = Snake Oil []
  26. Chia Seeds To The Rescue Of Type 2 Diabetics []
  27. Reprod. Nutr. Dev. 45 (2005) 581–597 581 Conversion of α-linolenic acid to longer-chain polyunsaturated fatty acids in human adults. Graham C. Burdge, Philip C. Calder. Institute of Human Nutrition, University of Southampton, Southampton, UK. []
  28. Polyphenols are collections of many (hence “poly-“) phenol structural units. Phenols are organic chemical compounds that have a pair of molecular groups stuck together – namely, a phenyl group with the molecular formula −C6H (six carbon atoms and one hydrogen atom) and a hydroxy group with the formula −OH (one oxygen atom and one hydrogen atom). When these bond together it forms a phenol with the formula C6H5OH. []
  29. Plant lignans include pinoresinol, lariciresinol, secoisolariciresinol, matairesinol, hydroxymatairesinol, syringaresinol and sesamin. []
  30. The other classes of phytoestrogens are isoflavones and coumestans. []
  31. Topic: Phytoestrogens. []
  32. Xenoestrogens are byproducts of the plastic and pesticide industries. Besides being a component of plastic, they are also found in conventional makeup/cosmetic products, household cleaners, laundry detergents, and some birth control medications. They are also found in sunscreens, chlorine and processed food. Naturally, with all this junk ending up in the oceans and rivers, fish become contaminated and people who eat fish thereby share in that contamination. []
  33. What’s the nutritional value of flaxseeds? []
  34. Wholism vs Reductionism – Not Just a War of Words []
  35. Sesamin is a lignan extracted from sesame seeds and a compound of sesame seed oil. A small amount is in flaxseeds. []
  36. Matairesinol is a plant lignan. It occurs with secoisolariciresinol in numerous foods such as oil seeds (including flaxseeds), whole grains, vegetables and fruits. []
  37. Pinoresinol is a lignan found in Styrax sp. and in Forsythia suspensa, as well as in the caterpillar of the cabbage butterfly, Pieris rapae where it serves as a defence against ants. It’s found in foods such as sesame seeds, Brassica vegetables, olive oil, and small amounts in flaxseeds. []
  38. Lariciresinol is a lignan, a type of phenylpropanoids. In food, it is found in sesame seeds and in Brassica vegetables. It is also found in the bark and wood of white fir. []
  39. Flaxseed Lignans: Biosynthesis, Metabolism, Antioxidant Activity, Bio‐Active Components, and Health Benefits. Alhassane Touré Xu Xueming. 29 April 2010. []
  40. Milder IE, Arts IC, van de Putte B, Venema DP, Hollman PC. Lignan contents of Dutch plant foods: a database including lariciresinol, pinoresinol, secoisolariciresinol and matairesinol. Br J Nutr. 2005;93(3):393-402. []
  41. Topic: Flax seeds. []
  42. There are websites that disagree with this, although there are few published studies showing negative effects, and those that do appear to relate more to consuming flax oil – usually called linseed oil. []
  43. Allergy Asthma Clin Immunol. 2010; 6(Suppl 2): P6. Flax seed allergy in children: an emerging allergen? Andrew O’Keefe, Sandeep Kapur, Gregory Rex, and Wade Watson. []
  44. J Cardiovasc Pharmacol. 2009 Nov;54(5):369-77. Flaxseed and cardiovascular health. Prasad K. []
  45. MayoClinic: Flaxseed and flaxseed oil. []
  46. J Food Sci Technol. 2014 Sep; 51(9): 1633–1653. Flax and flaxseed oil: an ancient medicine & modern functional food. Ankit Goyal, Vivek Sharma, Neelam Upadhyay, Sandeep Gill, Manvesh Sihag. []
  47. Oregon State University Linus Pauling Institute. Micronutrient Information Center: Lignans. []
  48. Two Types of Gut Bacteria: Plant Eaters’ & Meat Eaters’ []
  49. Dr. Greger’s Daily Dozen Checklist. Michael Greger M.D. FACLM March 30th, 2018 Volume 39 []
  50. Topics: Flax seeds. []
  51. Which Are Better: Chia Seeds or Flax Seeds? Michael Greger M.D. FACLM April 7th, 2017 Volume 35 []
  52. Flax Seeds for Hypertension. []
  53. Can Flax Seeds Help Prevent Breast Cancer? []
  54. Flax Seeds for Breast Pain. []
  55. Flax Seeds & Breast Cancer Survival: Clinical Evidence. []
  56. Flax Seeds & Breast Cancer Survival: Epidemiological Evidence. []
  57. Flaxseeds & Breast Cancer Prevention. []
  58. Just the Flax, Ma’am. Michael Greger M.D. FACLM August 22nd, 2007 Volume 1. []
  59. Flaxseeds vs. Prostate Cancer. []
  60. Flax Seeds vs. Diabetes. []
  61. Was It the Flaxseeds, Fat Restriction, or Both? []
  62. Flaxseeds for Sensitive Skin. []
  63. Flax Seeds vs. Chia Seeds. []
  64. Which Are Better: Chia Seeds or Flax Seeds? []
  65. Grapetree. Suppliers of flaxseeds. []
  66. Amazon: Duronic CG300 Electric Coffee Grinder Mill []