Does Milk Destroy Anti-Oxidants in Tea or Coffee?

coffee with miolkHow do you take yours?  A lot, a little or no milk in your tea or coffee?  Personally, I like my espresso with a little milk and topped with a little mound of foamy milk, not quite a macchiato nor a cappuccino but a mini version somewhere in between. But does milk really destroy the anti-oxidants in coffee or tea?

Lately, someone mentioned online information from a reputable doctor’s site that said so…citing the research et al.

My thoughts were, “here we go again…the old milk controversy”.  Every few years the ‘proof and research’ seems to go back and forth on this.

So, I read the research again as to the why (milk supposedly destroys anti-oxidants).  And indeed, laboratory results show that the milk protein, casein binds to the anti-oxidants in coffee or tea, rendering them no longer bio-available to the body.

Hmmm…really?  Over the years and observing research contradicting itself after a few years due to deeper studies or better research methods (remember the 70’s-80’s eggs-are-bad-for-you and the margarine-is-healthier-than-thou (err..butter) hype?  Oh yes, it took mainstream news and the average doctor nearly 20 years to accept the better research that pointed out the flaws in those myths.  In the meantime, John/Jane Q. Public was crying over their shift to a no more real butter nor eggs lifestyle and driving restaurants crazy with their ‘omelettes without egg yolks’ demands.  And feeling smug about it.

But, the question about dairy ‘destroying’ or better said rendering anti-oxidants bio-unavailable in tea and coffee is a valid one.  To a point.

To be clear, some laboratory research has demonstrated  that milk protein does indeed interact and bind to some anti-oxidants such as chlorogenic acid (an important phytochemical in coffee), making them rather useless to the body.  Most of the studies stopped there with the laboratory results and the word was spread to the mainstream media.

Meanwhile, other more recent research has followed this ‘problem’ deeper in human trials with blood tests, before, during and after ingestion of milk with coffee or tea. The results have demonstrated that this interaction doesn’t appear to negatively affect total antioxidant capacity.  This may partially have to do with an un-binding effect that naturally occurs during digestion.

One of my criticisms of this type of research is relying too much on in vitro studies and drawing conclusions from it.  But our bodies are far more complex than test tubes and petri dishes.  Double blind human tests with pre- during and after blood work results are more believable.  And conducted by independent research.  I did find research funded by Nestle.  Not a reliable source, in my sometimes-not-so-humble opinion.

During digestion, the milk protein ‘un-binds’ from the anti-oxidants in coffee or tea.

Interestingly, although the findings showed that adding milk did not significantly affect “the overall bio-availability of coffee phenolic acids” using sugar and nondairy creamer did.

From another perspective, adding milk to your tea or coffee has other benefits.  Not only does it contribute to bone health, but it lowers the temperature of the hot drink, protecting the sensitive tissues of the esophagus from thermal burns, thus lowering the risk of esophageal malignancies.

Still, if milk is not your ‘thing’, avoid the non-dairy coffee ‘creamer’ (have you looked at the chemicals in the ingredients list?) or soy based products and give almond milk a try. Add a sprinkle of Ceylon cinnamon to your coffee – delicious!

 

Selection of Resources:
Nondairy Creamer, but Not Milk, Delays the Appearance of Coffee Phenolic Acid Equivalents in Human Plasma,Journal of Nutrition, February 2010 vol. 140

Coffee Antioxidant Properties: Effects of Milk Addition and Processing Conditions, Journal of Food Science, Volume 71, Issue 3, April 2006

Effect of Roasting on Properties of the Zinc-Chelating Substance in Coffee Brews, Xu Wen,Akiko Enokizo, Harumi Hattori,Satiko Kobayashi,Masatsune Murata, and Seiichi Homma Department of Nutrition and Food Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan, J. Agric. Food Chem. 2005 volume 53 pp 2684–2689

Chlorogenic acid is poorly absorbed, independently of the food matrix: A Caco-2 cells and rat chronic absorption study, Molecular, Nutrition and Food Research , First published:19 October 2006

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