The Problem with Protein

 

How do you plant-eaters get enough protein?”

You might think that this is a question only asked by people who don’t know much about nutrition; but it is surprising just how many nutritionists, GP’s and writers of nutrition courses ask the same question. In this article, I would like to look at two aspects of protein: firstly, a comparison of protein content in animal and plant foods and, secondly, a look at the dangers of too much (animal) protein in the diet. But first, a quick definition of what protein actually is.

What is protein?

Protein is a nitrogen-containing chemical used to create body tissue as well as other chemicals (for instance, enzymes and hormones) that are very important in terms of participating in metabolism and maintaining the body in working order. Protein molecules are large and composed of long chains (polymers) of carefully sequenced amino acids. There are a huge number of different kinds of proteins, all of which are distinguished by the order that exists for the amino acids in that chain or polymer. The primary function of protein is as the basis for the almost unlimited number of enzymes, and enzymes are the molecules within the body that control metabolism. It is one of the three so-called macronutrients, the other two being fats (lipids) and carbohydrates which are composed of hydrogen and carbon.

It’s useful to understand that these macronutrients – and micronutrients (vitamins and minerals), for that matter – do not exist or function in isolation within the body. They work together as combinations, not as distinctly different entities, also working together within individual molecules. For example, glycoproteins are molecules where proteins and carbohydrates are joined together, while glycolipids are molecules where carbohydrates and lipid-containing substances are joined together. And, of course, you will be familiar with molecules that have a combination of lipids and proteins (lipoproteins) – namely, cholesterol in the form of LDL (low density lipoprotein) and HDL (high density lipoprotein) known as “bad” and “good” cholesterol respectively.

How much protein do I need?

Probably less than you would imagine. Opinions differ from authority to authority, but Professor T Colin Campbell, an expert in the field co-author of The China Study, suggests that calories derived from protein should ideally represent around 8-10% of total daily calorie (kcal) intake. So, for instance, if your daily calorie intake is 2000 calories, this would mean between 160 and 200 calories from protein. And since a gram of protein has 4 kcal of energy, this would be 40-50 grams of protein. Again, as a general rule, most authorities recommend we consume around 0.75 grams of protein for each kilogram of lean body weight. So, if you weigh 60 kilograms, this would imply that you need 45 grams (or 180 kcal) of protein a day. I will cover this subject in more detail in future articles – particularly whether protein intake has to be increased when you increase your levels of physical exercise.

What about protein-deficiency?

As far as my research goes, I have never found a single medical recording of protein deficiency within average western populations. The biggest problem is quite the opposite – excessive protein intake. Regarding the traditional and misinformed idea that people eating an exclusively plant-based diet should be very careful about combining proteins in order to get the right balance of essential amino acids, this is covered in my video The Protein Combining Myth – A Rat’s Tale.

COMPARISON OF PROTEIN CONTENT IN ANIMAL AND PLANT FOODS

For those of you who are making the transition from animal foods to plant foods, the following may well encourage you to ignore the ill-informed warnings about protein deficiency – especially in light of the fact that the greatest danger related to protein is over- not under-consumption.

To show how easy it is to get more than enough protein from plants, the following is a list of the foods and drinks taken from my diary three days ago. You will see that I consumed only 1420 kcal on this particular day, whilst on normal days my calorie intake would be between 2000 and 2500 kcal:

The above foods contained a total of 51.2 grams of protein, which represented 12% of total calories (fats made up 21% and carbohydrates 66%). I chose this day as an example because of the relatively low intake of calories. Normally, even with my usual macronutrient ratios (protein 10%/fat 20%/carbohydrate 70%), my protein intake from plant foods is more than necessary for optimal health and energy levels.

THE DANGERS OF TOO MUCH (ANIMAL) PROTEIN IN THE DIET

Kidney Disease

Most people don’t realise that high animal protein intake and kidney disease have been clearly linked for over 100 years (1., 2.). It’s one of the oldest known nutrition links and it has been proven repeatedly that if you take animals with reduced kidney function and give them extra amounts of protein, there is a significant acceleration in the decline of their kidney function. Research has also shown a relationship between increased protein consumption and increased development of kidney cancer. And the relationship between kidney cancer and animal protein consumption is about as strong as any other nutrition cancer linkage. This is why, for a long time, a recommendation for kidney health has been to reduce protein intake.

Cardiovascular Disease

Dr Thomas Campbell mentions a 2016 study (3.) which shows that “among two very large American study populations (female nurses and male health professionals), those that consumed the most animal protein compared to plant protein had a higher risk of death, particularly cardiovascular disease. Researchers found that when 3% of energy from plant protein was substituted for an equivalent amount of processed red meat protein, there was a 34% lower risk of death.

These findings are even more impressive when you consider the fact that researchers controlled for age, intake of different types of fat, total energy intake, glycemic index, and intake of whole grains, fiber, fruits and vegetables, smoking, body mass index, vitamin use, physical activity, alcohol intake, history of high blood pressure. In other words, they statistically eliminated many of the beneficial components of plant-based diets to try to isolate the sole effect of dietary protein and still found an effect. When data was adjusted only for age, total energy and fat intake, those consuming the most plant protein were found to have 33% reduced risk of death, 40% reduced risk of cardiovascular death, and 28% reduced risk of cancer death.

This is even more remarkable given the meat-centered diets that study subjects were consuming. Researchers divided the population into groups based on the amount of protein consumed. Even those consuming the most plant-protein consumed almost 60% more animal protein than they did plant protein. None of these groups were consuming anything remotely similar to the whole-food plant-based diet that has been shown to halt or reverse advanced heart disease, diabetes, and early stage prostate cancer.”

Osteoporosis

Can protein have a detrimental effect on bone? Optimal amounts of protein are not only beneficial but essential for bone health since they improve bone mass – as long as sufficient calcium is also in the diet – and thus reduce potential fractures. However, too much dietary protein can have a detrimental effect on bone – that is if protein (in meat, fish and dairy products) is consumed well in excess of bodily needs. This is because excess protein will increase the acidity of bodily fluids and compartments. The knock-on effect of this is that, over an extended period of time, the alkaline minerals (including calcium and phosphorus) will leach from the bones in an attempt to recreate the ideal state of pH homeostasis. During this process some of this calcium released into the bloodstream will be lost in the urine. This situation is further complicated by factors such as the acid/base status of other foods in the diet, the source of the proteins consumed, and the amount of overall calcium intake.

SAD (Stand American Diets) or modern western diets increase the risk of osteoporosis and associated fractures (4.) because they are so high in animal proteins – affecting the pH balance as indicated above. Not all proteins are equal in relation to the effect they have on bone. Meat, fish and eggs are thought to be particularly linked to increased urinary excretion of calcium because they are particularly acid-forming in their effects on the body. However, consuming alkaline plant-based foods (which will still contain protein) has a decreasing effect on the amount of calcium excreted as urine. Another factor is the calcium-potassium balance: being found mainly in fruits and vegetables, potassium has an additional alkalising effect, thereby reducing calcium excretion and maintaining bone health. Thus, it is not just a matter of reducing the amount of protein consumed, but ensuring that the appropriate sources and amounts of proteins are balanced with increased fruit and vegetable consumption.


References

1. Robertson, W. G. Miner Electrolyte Metab., 13: 228-234, 1987.

2. Robertson, W. G. et al. Chron. Dis., 32: 469-476, 1979.

3. Song M, Fung T, Hu FB, et al.Association of Animal and Plant Protein Intake With All-Cause and Cause-Specific Mortality. JAMA Intern Med 2016.

4. Sellmeyer DE , Stone KL , Sebastian A , Cummings SR. The American Journal of Clinical Nutrition [01 Jan 2001, 73(1):118-122]. A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Study of Osteoporotic Fractures Research Group.

 

Alkaline Diet – So What?!

Alkaline no Cancer Otto Warburg

Joe’s Comment

I was recently asked why it was that I was so pleased that two of my clients’ daily food diaries were showing a healthy alkaline balance. The following* should explain the main reasons – contact me if anything is unclear or if you need personal advice:

Article 1

Amended excerpts from How Not To Die by Dr Michael Greger

[A]nimal protein may be so detrimental to kidney function [because] it is generally more acid forming. This is because animal protein tends to have higher levels of sulfur-containing amino acids, such as methionine, which produce sulfuric acid when metabolized in the body. Fruits and vegetables, on the other hand, are generally base forming, which helps neutralize acids in our kidneys. 32 Dietary acid load is determined by the balance of acid-inducing foods (such as meats, eggs, and cheese) and base-inducing foods (such as fruits and vegetables).

A 2014 analysis of the diets and kidney function of more than twelve thousand Americans across the country found that a higher dietary acid load was associated with significantly higher risk of protein leakage into the urine, an indicator of kidney damage. 33 Ancient human diets largely consisted of plants, so they likely produced more base than acid in the kidneys of our ancestors.

Humans evolved eating these alkaline (base-forming) diets over millions of years. Most contemporary diets, on the other hand, produce acid in excess. This switch from base-to acid-forming diets may help explain our modern epidemic of kidney disease. 34 Acid-inducing diets are believed to impact the kidney through “tubular toxicity,” damage to the tiny, delicate, urine-making tubes in the kidneys. To buffer the excess acid formed by your diet, kidneys produce ammonia, which is a base and can neutralize some of that acid.

Counteracting the acid is beneficial in the short term, but over the long run, all the extra ammonia in the kidneys may have a toxic effect. 35 The decline in kidney function over time may be a consequence of a lifetime of ammonia overproduction. 36 Kidneys may start to deteriorate in your twenties, 37 and by the time you reach your eighties, you may be down to half capacity. 38 The chronic, low-grade, metabolic acidosis attributed to a meat-rich diet 39 helps explain why people eating plant-based diets appear to have superior kidney function 40 and why various plant-based diets have been so successful in treating chronic kidney failure. 41,42 Under normal circumstances, a vegetarian diet alkalinizes the kidneys, whereas a nonvegetarian diet carries an acid load. This proved to be true even among vegetarians who consumed processed meat substitutes, such as veggie burgers. 43

If people are unwilling to reduce their meat consumption, they should be encouraged to eat more fruits and vegetables to balance out that acid load. 44 “However,” one kidney doctor editorialized, “many patients find it difficult to follow a diet high in fruits and vegetables and might therefore be more adherent to a supplement.” 45

So what did researchers try? Giving people bicarbonate of soda (sodium bicarbonate) pills. Instead of treating the primary cause of the excess acid formation (too many animal products and too few fruits and vegetables), they preferred to treat the consequences. Too much acid? Here’s some base to neutralize it. Sodium bicarbonate can effectively buffer the acid load, 46 but, rather obviously, sodium bicarbonate contains sodium, which over the long term may itself contribute to kidney damage. 47

Unfortunately, this type of sticking-plaster approach is all too typical of today’s medical model. Cholesterol too high from eating a diet unnaturally high in saturated fat and cholesterol? Take a statin drug to cripple your cholesterol-making enzyme. Diet unnaturally high in acid-forming foods? Swallow some bicarbonate of soda pills to balance that right out. These same researchers also tried giving people fruits and vegetables instead of bicarbonate of soda and found that they offered similar protections, with the additional advantage of lowering the subjects’ blood pressure. The title of the accompanying commentary in the medical journal was telling: “The Key to Halting Progression of CKD [Chronic kidney disease} Might Be in the Produce Market, Not in the Pharmacy.” 48

Fruit and Veg 002

Eating a plant-based diet to alkalinize your urine may also help prevent and treat kidney stones— those hard mineral deposits that can form in your kidneys when the concentration of certain stone-forming substances in your urine becomes so high they start to crystallize. Eventually, these crystals can grow into pebble-sized rocks that block the flow of urine, causing severe pain that tends to radiate from one side of the lower back toward the groin. Kidney stones can pass naturally (and often painfully), but some become so large that they have to be removed surgically….

…Bottom line: When urine is more alkaline, stones are less likely to form. This helps explain why less meat and more fruits and vegetables appear so protective. The standard American diet yields acidic urine. When people are placed on a plant-based diet, however, their urine can be alkalinized up to a near neutral pH in less than a week. 63

Not all plant foods are alkalinizing, though, and not all animal foods are equally acidifying. The LAKE (Load of Acid to Kidney Evaluation) score takes into account both the acid load of foods and their typical serving sizes in order to help people modify their diets for the prevention of kidney stones and other acid-related diseases, such as gout. As you can see in figure 4, the single most acid-producing food was fish, including tuna, followed by pork, poultry, cheese, and beef. Eggs are actually more acid producing than beef, but people tend to eat fewer of them at one sitting. Some grains can be a little acid forming, such as bread and rice, but not pasta, interestingly. Beans are significantly acid reducing, but not as much as fruits are, with vegetables crowned the most alkaline forming of foods. 64

Acid Load on Kidneys How Not To Die.jpg

Test to see if your diet is alkaline- or acid-forming.


 

Article 2

Amended excerpts from “The Alkaline Advantage How pH Promotes Optimal Health and Performance” by from nutritionstudies.org

“It amazes me how little attention the value of balanced pH has garnered from the mainstream medical world.”

Positive acid/alkaline balance is one of the most important factors in athletic performance. In my opinion, by disregarding this fact, sport supplement manufacturers have significantly reduced the effectiveness of their products. In fact some of the energy bars currently on the market are the worst offenders. Processed for the sake of shelf life and convenience, and consequently denatured and acid forming, many energy bars are not much more than disguised junk food.

When acidic forming food is consumed, starting with digestion and continuing until elimination, it produces toxins that the body must deal with. Denatured foods are toxin producers and as a result have the greatest negative impact on pH balance within the body. Highly refined and processed, denatured foods are void of any usable nutrients, yet retain their caloric value – the worst combination. Toxins in the body lead to premature aging through cell degeneration. Aside from food, most prescription drugs, artificial sweeteners and synthetic vitamin and mineral supplements are extremely acid-forming.

Athletes in peak training are the most affected by acidosis. Vigorous exercise creates stress in terms of muscle trauma cased by the workout. Physiologically speaking, hard exercise is the stressor but equally important is rest and recovery. The correct balance of theses two opposing elements is the recipe for growth. Already physically stressed, many athletes also must deal with various types of performance anxiety. An increased metabolism is yet another factor athletes are met with, further lowering pH. Furthermore, athletes require more food in general with an emphasis on protein to aid muscle recovery.

Alkaline Diet.png

For recovery to be expedited, alkalizing foods, such as those rich in chlorophyll, need to be consumed soon after exercise. Protein must also be consumed to help repair broken down muscle tissue. As with processed energy bars, numerous sport supplements touted as post-work-out recovery agents contain highly processed, manufactured proteins usually in the form of denatured isolates, which are acid forming. Suggesting they be consumed soon after a workout will fulfil the body’s need for protein, but completely neglect its need for pH balancing.

The paradox is this; most protein sources are highly acid forming, yet the highly alkaline forming foods are generally low in protein. This can be overcome if the protein sources are chosen carefully. Raw, unprocessed, natural, hemp protein, for example, measures at about 50% protein, yet is greatly less acid forming than common denatured ones such as soy and whey. Hemp’s higher pH level can be attributed in part to chlorophyll content, responsible for its green colour. Chlorella is another great protein-rich pH booster, containing almost 70% protein, yet it is highly alkalizing. As a general rule, the most alkalizing foods are raw, unprocessed, whole and rich in chlorophyll. Raw, sprouted legumes such as lentils, beans and seeds are also a superior source of alkalizing protein. Also, a diet high in leafy green vegetables, which are excellent sources of chlorophyll, will help insure the system remains alkaline even when stress levels are elevated. [Joe’s comment: Be careful about supplementing with protein products, whether from plants or otherwise. Watch the video by Prof T Colin Campbell about protein requirements and effect of excessive protein on health.]

In addition to curtailing recovery, pH imbalance is a trigger for many ailments. Those who maintain an acidic environment within their body are also prone to fatigue. Since acidity is a stressor, cortisol levels rise resulting in impaired sleep quality, thus further exacerbating the problem.

Contrary to popular belief, it is stress and the over consumption of acid forming foods, not a lack of dietary calcium, that lead to most cases of poor bone health and eventually osteoporosis. The blood itself will always remain neutral as this is imperative for survival. However, if the body is consistently fed acid forming denatured foods and supplements, or encounters stress from other sources, it must take measures to ensure a neutral blood pH is maintained. To do so, the body pulls alkaline calcium from the bones. Over time, the bones become weaker as a result of this survival mechanism.

The conventional way of treating low calcium levels and osteoporosis is to simply suggest the person take more calcium, usually in the form of tablets. The calcium source in tablets is generally derived from materials such as oyster shells, bovine bone meal, coral and dolomite (rock), all of which are extremely hard and unnatural for the body to assimilate. The large size and recommended daily number to be consumed is a testament to their poor bioavailability. The body must work very hard to get calcium from these sources, another reason why this method of boosting calcium levels in our body is inferior.

Low-grade metabolic acidosis as it is termed, is another symptom of an over acidic body. It has been cited as a leading cause of several health concerns such as the development of kidney stones, loss of bone mass, and the reduction of growth hormone, therefore resulting in a decline in lean muscle mass and an increase of body fat. Since low-grade metabolic acidosis affects the body at a cellular level it is also responsible for an increase in the fabrication of free radicals, and a loss in cellular energy production. In addition to these serious concerns, viral and bacterial growth is able to thrive in an acidic body, possibly leading to a wide variety of diseases. On the other hand disease is rare in an alkaline body; cancer, for example, cannot develop in an alkaline environment.

Though diet has the single greatest impact on the body’s pH balance, there are other things that can also help. For example, taking time out of a busy schedule to do something pleasurable yet seemingly unproductive can actually be a key ingredient to improved pH balance, improved health and longevity.

Brendan Brazier is the creator and host of the Thrive Forward web series, based on his bestselling Thrive book trilogy (Thrive, Thrive Fitness, and Thrive Foods). Brendan is a former professional Ironman triathlete, and the creator of an award-winning line of whole food nutritional products called Vega. He is also a two-time Canadian 50km Ultra Marathon Champion. Brendan is recognized as one of the world’s foremost authorities on plant-based nutrition for athletes. He is a lecturer for our Plant-Based Nutrition Certificate through eCornell where he presents a lecture based on his best-selling books entitled: Plant-Based Diet and Elite Athleticism.

Article 3

Amended Excerpts from “Excess Protein Damages the Bones = Osteoporosis” by Dr John McDougall

From The McDougall Newsletter January 2004

Osteoporosis is caused by several controllable factors; however, the most important one is the foods we choose – especially the amount of animal protein and the foods high in acid.17-19 The high acid foods are meat, poultry, fish, seafood, and hard cheesesparmesan cheese is the most acidic of all foods commonly consumed.20 This acid must be neutralized by the body. 21 Carbonate, citrate and sodium are alkaline materials released from the bones to neutralize the acids. Fruits and vegetables are alkaline and as a result a diet high in these plant foods will neutralize acid and preserve bones. The acidic condition of the body caused by the Western diet also raises cortisol (steroid) levels. 22 Elevated cortisol causes severe chronic bone loss – just like giving steroid medication for arthritis causes severe osteoporosis.

Consequence…: Kidney Stones

Once materials are released from the solid bone, the calcium and other bone substances move through the blood stream to the kidneys where they are eliminated in the urine. In an effort to remove the overabundance of waste protein, the flow of blood through the kidneys (glomerular filtration rate) increases – the result: calcium is filtered out of the body. Naturally, the kidneys attempt to return much of this filtered calcium back to the body; unfortunately, the acid and sulfur-containing amino acids from the animal foods thwart the body’s attempts to conserve calcium. The final result is each 10 grams of dietary protein in excess of our needs (30 grams daily) increases daily urinary calcium loss by 16 mg. Another way of looking at the effects is: doubling protein intake from our diet increases the loss of calcium in our urine by 50%.25 Plant proteins (plant food-bases) do not have these calcium and bone losing effects under normal living conditions. Once this bone material arrives in the collecting systems of the kidney it easily precipitates into sold formations known as kidney stones.27 Over 90% of kidney stones found in people following a high-protein, Western diet are formed primarily of bone-derived calcium. Following a healthy diet is the best way to prevent kidney stones.28
Eating Animal Foods Promotes Kidney Stones.jpg

 


Sources: Article 1.

Greger, Michael; Stone, Gene. How Not To Die: Discover the foods scientifically proven to prevent and reverse disease (Air Side Edt) (p. 167-72). Pan Macmillan. Kindle Edition.

  1. Frassetto L, Morris RC, Sellmeyer DE, Todd K, Sebastian A. Diet, evolution and aging— the pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet. Eur J Nutr. 2001;40( 5): 200– 13.

  2. Banerjee T, Crews DC, Wesson DE, et al. Dietary acid load and chronic kidney disease among adults in the United States. BMC Nephrol. 2014 Aug 24;15: 137.

  3. Sebastian A, Frassetto LA, Sellmeyer DE, Merriam RL, Morris RC. Estimation of the net acid load of the diet of ancestral preagricultural Homo sapiens and their hominid ancestors. Am J Clin Nutr. 2002;76( 6): 1308– 16.

  4. van den Berg E, Hospers FA, Navis G, et al. Dietary acid load and rapid progression to endstage renal disease of diabetic nephropathy in Westernized South Asian people. J Nephrol. 2011;24( 1): 11– 7.

  5. Uribarri J, Oh MS. The key to halting progression of CKD might be in the produce market, not in the pharmacy. Kidney Int. 2012;81( 1): 7– 9.

  6. Cohen E, Nardi Y, Krause I, et al. A longitudinal assessment of the natural rate of decline in renal function with age. J Nephrol. 2014;27( 6): 635– 41.

  7. Brenner BM, Meyer TW, Hostetter TH. Dietary protein intake and the progressive nature of kidney disease: the role of hemodynamically mediated glomerular injury in the pathogenesis of progressive glomerular sclerosis in aging, renal ablation, and intrinsic renal disease. N Engl J Med. 1982 Sep 9;307( 11): 652– 9.

  8. Frassetto LA, Todd KM, Morris RC, Sebastian A. Estimation of net endogenous noncarbonic acid production in humans from diet potassium and protein contents. Am J Clin Nutr. 1998;68( 3): 576– 83.

  9. Wiseman MJ, Hunt R, Goodwin A, Gross JL, Keen H, Viberti GC. Dietary composition and renal function in healthy subjects. Nephron. 1987;46( 1): 37– 42.

  10. Kempner W. Treatment of heart and kidney disease and of hypertensive and arteriosclerotic vascular disease with the rice diet. Ann Intern Med. 1949;31( 5): 821– 56.

  11. Barsotti G, Morelli E, Cupisti A, Meola M, Dani L, Giovannetti S. A low-nitrogen low-phosphorus vegan diet for patients with chronic renal failure. Nephron. 1996;74( 2): 390– 4.

  12. Deriemaeker P, Aerenhouts D, Hebbelinck M, Clarys P. Nutrient based estimation of acid-base balance in vegetarians and non-vegetarians. Plant Foods Hum Nutr. 2010;65( 1): 77– 82.

  13. Goraya N, Simoni J, Jo C, Wesson DE. Dietary acid reduction with fruits and vegetables or bicarbonate attenuates kidney injury in patients with a moderately reduced glomerular filtration rate due to hypertensive nephropathy. Kidney Int. 2012;81( 1): 86– 93.

  14. Yaqoob MM. Treatment of acidosis in CKD. Clin J Am Soc Nephrol. 2013;8( 3): 342– 3.

  15. Goraya N, Simoni J, Jo C, Wesson DE. Dietary acid reduction with fruits and vegetables or bicarbonate attenuates kidney injury in patients with a moderately reduced glomerular filtration rate due to hypertensive nephropathy. Kidney Int. 2012;81( 1): 86– 93.

  16. Wright JA, Cavanaugh KL. Dietary sodium in chronic kidney disease: a comprehensive approach. Semin Dial. 2010;23( 4): 415– 21.

  17. Uribarri J, Oh MS. The key to halting progression of CKD might be in the produce market, not in the pharmacy. Kidney Int. 2012;81( 1): 7– 9.

  18. Trinchieri A. Development of a rapid food screener to assess the potential renal acid load of diet in renal stone formers (LAKE score). Arch Ital Urol Androl. 2012;84( 1): 36– 8.


Sources: Article 2

The Alkaline Advantage How pH Promotes Optimal Health and Performance


 

Sources: Article 3

17) Maurer M. Neutralization of Western diet inhibits bone resorption independently of K intake and reduces cortisol secretion in humans. Am J Physiol Renal Physiol. 2003 Jan;284(1):F32-40.

18) Remer T. Influence of diet on acid-base balance. Semin Dial. 2000 Jul-Aug;13(4):221-6.

19) Frassetto L. Diet, evolution and aging–the pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet. Eur J Nutr. 2001 Oct;40(5):200-13.

20) Remer T. Potential renal acid load of foods and its influence on urine pH. J Am Diet Assoc. 1995 Jul;95(7):791-7.

21) Barzel US. Excess dietary protein can adversely affect bone. J Nutr. 1998 Jun;128(6):1051-3.

22) Maurer M. Neutralization of Western diet inhibits bone resorption independently of K intake and reduces cortisol secretion in humans. Am J Physiol Renal Physiol. 2003 Jan; 284(1): F32-40. Epub 2002 Sep 24.

23) Remer T. Potential renal acid load of foods and its influence on urine pH. J Am Diet Assoc. 1995 Jul;95(7):791-7.

24) J Pennington. Bowes & Church’s Food Values of Portions Commonly Used. 17th Ed. Lippincott. Philadelphia- New York. 1998.

25) Massey LK . Dietary animal and plant protein and human bone health: a whole foods approach. J Nutr. 2003 Mar; 133(3): 862S-865S.

26) Jenkins DJ. Effect of high vegetable protein diets on urinary calcium loss in middle-aged men and women. Eur J Clin Nutr. 2003 Feb;57(2):376-82.

27) Lemann J Jr. Relationship between urinary calcium and net acid excretion as determined by dietary protein and potassium: a review. Nephron. 1999; 81 Suppl 1: 18-25.

28) Delvecchio FC. Medical management of stone disease. Curr Opin Urol. 2003 May; 13(3): 229-33.

* I have abbreviated and highlighted words/sections as I thought appropriate. Original sources are indicated and are available for inspection.