Cow’s Milk Increases Health Benefits of Coffee, Tea and Berries?

Coffee 1 2 , tea 3  and berries 4 have all been shown to have significant health benefits; but what happens to those benefits if you add cow’s milk to your cuppa, cream to a bowl of your favourite berries (blueberries, strawberries etc)? Do you think those benefits will be increased or deceased? Read on…

Coffee & chlorogenic acid

It’s thought that a phytochemical found in coffee, called chlorogenic acid 5 , not only reduces blood sugar levels – thus having an anti-diabetic effect, but also helps us to lose weight – thus having an anti-obesity effect, improves endothelial cell function and blood pressure 6 , and has antioxidant properties 7 .

However, it’s been shown 8 9 that the more you roast the coffee beans, the more of the chlorogenic acid is destroyed.

But what happens when you add cow’s milk to your coffee?

Tea & catechins/theaflavins

It’s been shown 10 3 that tea (black and green) is a pretty healthy drink, partly because it both acts as an antioxidant and is good at improving flow-mediated dilation 11 , that is, it helps blood vessels relax and lets blood flow more easily.

In green tea, the important antioxidant polyphenols are called catechins, and in black tea they are called theaflavins 12 .

It’s been shown 13 that the addition of cow’s milk to your cup of tea will completely inhibit the beneficial effects on artery function provided by drinking tea without added cow’s milk.

Berries & caffeic acid/ferulic acid

Research increasingly reveals14 that consumption of berries can produce significant health benefits, particularly with regard to their powerful antioxidant properties.

Two of the dietary phenols 15 involved in this beneficial effect are called caffeic acid 16  and ferulic acid 17 .

A 2009 study 18 looked at blueberries being consumed with or without added dairy. The results were very clear:

  • blueberries eaten on their own enhanced plasma concentrations of caffeic acid and ferulic acid, (that is, increased plasma antioxidant capacity)
  • blueberries eaten with dairy (in this case milk, but cream would presumably have a similar effect) impaired plasma concentrations of caffeic acid and ferulic acid (that is, reduced plasma antioxidant capacity)

What mechanisms are involved?

It’s thought that the casein (a protein in cow’s milk) is responsible because it binds to the phytonutrients and prevents them from being available to the body.

So what about plant milks?

There are plenty of benefits of plant milks (soy, almond, oat, etc), but do they have the same negative nutrient-binding/blocking effect on tea and coffee as cow’s milk?

A 2015 study 19 gave us the answer to this question when it tested the results of drinking black coffee against drinking coffee with added soy milk.

The above charts show that there was no significant difference between available levels of chlorogenic acids and isoflavones when you consumed black coffee or coffee with soy milk. Although there needs to be further research, similar results would likely be found with other plant milks (oat, almond, etc).

A glass of milk in every bar

It probably comes as no surprise, then, that research 20 shows dark chocolate retains more nutrients than milk chocolate – not simply because there’s a higher ratio of cocoa, which we know 21 is beneficial on its own, but because of the higher level of milk in the milk chocolate.

The same nutrient-robbing effect probably applies when you have a glass of milk with your meal, although more studies are needed in this area since, historically, there’s been a tendency to beef up the benefits of cow’s milk, in spite of known health problems associated with it 22 .

Final thoughts

It’s quite true that there are some downsides to drinking coffee (such as its cholesterol-increasing potential, depending on how it’s prepared 23 ) ; but the upsides make it a useful beverage – when drunk black or with plant milk.

Tea is a great drink and there are no downsides worth mentioning that I’ve come across, except if it’s drunk with cow’s milk.

And, finally, to berries. There’s nothing but good things to say about them – so long as you keep them away from dairy. They are a central part of Joel Fuhrman’s G-BOMBS 24 and Dr Greger’s Daily Dozen 25 , and that’s good enough credentials for me. I have lots of them every day (taken from the freezer, defrosted in the microwave and added to my morning mountain of fruit and oaty goodness).

So, another great reason to leave the cow’s milk for a drinker who will benefit from it…


References

  1. Loftfield E, Freedman ND, Graubard BI, et al. Association of Coffee Consumption With Overall and Cause-Specific Mortality in a Large US Prospective Cohort Study. Am J Epidemiol. 2015;182(12):1010-1022. []
  2. Crippa A, Discacciati A, Larsson SC, Wolk A, Orsini N. Coffee consumption and mortality from all causes, cardiovascular disease, and cancer: a dose-response meta-analysis. Am J Epidemiol. 2014;180(8):763-775. []
  3. Curr Pharm Des. Author manuscript; available in PMC 2014 Jun 12. Tea and Health: Studies in Humans. Naghma Khan and Hasan Mukhtar. [] []
  4. Nutr Rev. Author manuscript; available in PMC 2011 Mar 31. Berries: emerging impact on cardiovascular health. Arpita Basu, Michael Rhone, and Timothy J Lyons. []
  5. Summary of chlorogenic acid. []
  6. Mubarak A, Bondonno CP, Liu AH, et al. Acute effects of chlorogenic acid on nitric oxide status, endothelial function, and blood pressure in healthy volunteers: a randomized trial. J Agric Food Chem. 2012;60(36):9130-9136. []
  7. Corrêa TA, Monteiro MP, Mendes TM, et al. Medium light and medium roast paper-filtered coffee increased antioxidant capacity in healthy volunteers: results of a randomized trial. Plant Foods Hum Nutr. 2012;67(3):277-282. []
  8. Ludwig IA, Mena P, Calani L, et al. Variations in caffeine and chlorogenic acid contents of coffees: what are we drinking?. Food Funct. 2014;5(8):1718-1726. []
  9. Mills CE, Oruna-Concha MJ, Mottram DS, Gibson GR, Spencer JP. The effect of processing on chlorogenic acid content of commercially available coffee. Food Chem. 2013;141(4):3335-3340. []
  10. Chin Med. 2010; 5: 13. Beneficial effects of green tea: A literature review. Sabu M Chako, Priya T Thambi, Ramadasan Kuttan, Ikuo Nishigaki. []
  11. Wikipedia: Definition of flow-mediated dilation. []
  12. Antioxidant Activity of Black Tea vs. Green Tea. Ki Won Lee Hyong Joo Lee Chang Yong Lee
    The Journal of Nutrition, Volume 132, Issue 4, 1 April 2002, Pages 785, https://doi.org/10.1093/jn/132.4.785. []
  13. Lorenz M, Jochmann N, Von Krosigk A, et al. Addition of milk prevents vascular protective effects of tea. Eur Heart J. 2007;28(2):219-223. []
  14. Nutr Rev. Author manuscript; available in PMC 2011 Mar 31. Berries: emerging impact on cardiovascular health. Arpita Basu, Michael Rhone, and Timothy J Lyons. []
  15. Wikipedia definition: polyphenols/phenols []
  16. Healthline: More on caffeic acid []
  17. J Clin Biochem Nutr. 2007 Mar; 40(2): 92–100. Ferulic Acid: Therapeutic Potential Through Its Antioxidant Property. Marimuthu Srinivasan, Adluri R. Sudheer, and Venugopal P. Menon. []
  18. Serafini M, Testa MF, Villaño D, et al. Antioxidant activity of blueberry fruit is impaired by association with milk. Free Radic Biol Med. 2009;46(6):769-774. []
  19. Felberg I, Farah A, Monteiro MC, de O. Godoy RL, Pacheco S, et al. Effect of simultaneous consumption of soymilk and coffee on the urinary excretion of isoflavones, chlorogenic acids and metabolites in healthy adults. J Funct Foods. 2015;19:688-699. []
  20. Serafini M, Bugianesi R, Maiani G, Valtuena S, De Santis S, Crozier A. Plasma antioxidants from chocolate. Nature. 2003;424(6952):1013. []
  21. Benefits of cocoa []
  22. Cow’s Milk – But It Looks So Innocent… []
  23. Coffee Increases Cholesterol Levels []
  24. G-BOMBS []
  25. Daily Dozen []

2 thoughts on “Cow’s Milk Increases Health Benefits of Coffee, Tea and Berries?

    1. I think you misunderstood the research findings mentioned in this blog. The addition of cow’s milk to your cup of tea will completely inhibit the beneficial effects on artery function provided by drinking tea without added cow’s milk.

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