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Milk and Tea Controversy

December 29, 2009 Written by JP       [Font too small?]

When we go out with a group of friends, something kind of amusing often happens. During the course of the afternoon or evening, someone will pull me aside and bring up a health issue that they’ve read about or seen covered on the local news. “So what’s this I hear about coffee ‘curing’ diabetes?” “Is it okay to cook with extra virgin olive oil or should I just use it in salads?” “What’s the big deal about gluten?”. I love fielding these questions because it tests my knowledge and gives me a better idea of what kind of information is being spread over various media outlets.

The topic of a recent conversation I had related to a pretty volatile issue among tea connoisseurs worldwide: Does adding milk to black tea negate its health benefits? I had never specifically studied this topic, but I knew that some heavy-hitters in the integrative medical community, such as Dr. Andrew Weil, have recommended against this combination. But I like to verify things for myself, so I did. Here’s what I discovered when looking into this “brewhaha”.

Before I get into the actual studies relating to this controversy, I’d first like to share some recent data that supports the use of black tea in general. A trial published in the December edition of the journal Toxicology found that 9 grams (about 3 cups worth) of black tea daily for 12 weeks can lower the levels of two cardiovascular risk factors: C-reactive protein and uric acid. A review from May 2009 “suggests that daily consumption of either green or black tea equaling 3 cups per day could prevent the onset of ischemic stroke”. The protection against strokes may, in part, be due to improved circulation via decreased arterial stiffness and an increase in nitric oxide production. (1,2,3,4)

  • Study #1 – Molecular Nutrition and Food Research (Sept. 2007)

Verdict: Pro-milk. Adding cow’s milk, rice milk or soy milk increased the antioxidant bioavailability of tea by 52%, 69% and 55% respectively. However, this was only a test tube (“in vitro”) experiment. (5)

  • Study #2 – The Journal of Agricultural Food Chemistry (May 2007)

Verdict: Pro-milk. Consumption of 400 mL of black tea resulted in a significant increase in “plasma antioxidant capacity” in a group of volunteers. This finding was “unaffected by adding milk”. (6)

  • Study #3 – European Heart Journal (Jan. 2007)

Verdict: Anti-milk. The addition of 10% skimmed milk to 500 mL of “freshly brewed black tea” negated the circulation enhancing affects found when black tea was administered without dairy. The researchers concluded that a group of proteins in milk (caseins) appeared to bind to healthful phytochemicals in tea, thereby forming complexes that couldn’t be absorbed efficiently. (7)

  • Study #4 – Anticancer Research (Sept.-Oct. 2003)

Verdict: Mixed. A test tube study found that skimmed milk did result in a loss of an important component of black tea (theaflavins). However, this change did not appear to decrease the anti-cancer activity of the tea itself. The researchers commented that “the antimutagenic activity of green and black teas is not modulated by the presence of skimmed milk, even at high concentrations”. (8)

  • Study #5 – The Journal of Agricultural Food Chemistry (Feb 2002)

Verdict: Anti-milk. A specific protein in milk, beta-casein, was found to “mask” the antioxidant potential of two key phytochemicals in tea (epigallocatechin gallate or EGCG and gallic acid). (9)

  • Study #6 – Free Radical Research (March 2001)

Verdict: Pro-milk. Drinking black tea alone or with added milk did not affect the concentrations of tea-based antioxidants (kaempferol or quercetin) in a group of 18 volunteers. The authors of this study remarked that tea “bioavailability is not affected by addition of milk”. (10)

  • Study #7 – Indian Journal of Physiology and Pharmacology (April 2000)

Verdict: Anti-milk. In this experiment, adding lemon to tea improved its antioxidant activity. But the addition of milk nullified tea’s antioxidant properties. The conclusion of this laboratory trial states that, “tea without milk is a good source of antioxidants and addition of lemon to tea increases its antioxidant potential”. (11)

  • Study # 8 – European Journal of Clinical Nutrition (Jan 2000)

Verdict: Pro-milk. A single dose of black or green tea increases “plasma antioxidant activity”. This effect was not abolished by the addition of milk in this study. (12)

  • Study #9 – The Proceedings of the Society for Experimental Biology and Medicine (April 1999)

Verdict: Pro-milk. Tea was shown to increase the antioxidant content in the blood of 18 healthy volunteers and “milk did not affect any of the parameters measured”. (13)

  • Study #10 – European Journal of Clinical Nutrition (May 1998)

Verdict: Pro-milk. Scientists measured the levels of catechins (a class of antioxidants found in tea) in 7 women and 5 men who drank controlled quantities of black tea, green tea and tea + milk blends. The researchers concluded that, “Catechins from green tea and black tea are rapidly absorbed and milk does not impair the bioavailability of tea catechins”. (14)

  • Study #11 – European Journal of Clinical Nutrition (Jan. 1996)

Verdict: Anti-milk. This study was a little different than most. It involved 10 participants and tested the effect of whole milk (not skimmed) on tea’s antioxidant activity. Green tea was found to be six times more potent than black tea, as measured by “human plasma antioxidant capacity” or TRAP. Mixing either tea with milk “totally inhibited” their antioxidant effect in vivo (in the body). The same effect was not found “in vitro”, which suggests that a reaction between components found in tea and milk likely occurs during the normal digestive process but not in test tubes. (15)

Some Studies Indicate That Tea and Tea + Milk Provide Comparable Antioxidant Activity
Source: J. Agric. Food Chem., 2007, 55 (12) (a)

To summarize: Some studies indicate that milk does impede the benefits of black and green tea while other experiments say otherwise. But you may be wondering whether there’s any advantage of adding milk to tea. In fact, there is. Black tea is an abundant source of dietary oxalates, substances which can lead to kidney stones in certain people. Adding milk to black tea reduces the availability of the natural oxalates found in tea. It’s believed that the calcium content of milk binds with the soluble oxalates and, thereby, limits their absorption. (16,17,18)

Another benefit that cold milk can offer is to lower the temperature of tea. The chronic ingestion of very hot tea has been linked to an increased risk of esophageal and gastric cancer. Teas with added milk tend to have a “lower starting temperature” and make it less likely for the drinker to suffer from thermal damage. (19,20,21,22)

Here’s the bottom line as far as I’m concerned: Milk probably prevents black tea from living up to its full potential. There’s a plausible theory about why this happens (the “milk protein hypothesis”) and enough red flags to warrant caution. If I enjoyed adding milk to tea, I’d do one of two things: 1) use a low-protein milk-alternative, such as almond or coconut milk instead of cow’s milk or; 2) use organic cream which is virtually free of protein. On the other hand, if you have a history of kidney stones and you enjoy drinking black tea, then certainly enjoy a splash of milk in it. It just might save you for a lot of anguish down the line. That’s the whole scoop and nothing but the scoop on the tea/milk controversy. If new information emerges that adds a twist or two to this tale, I’ll be sure to update you all right here. Cheers!

Be well!

JP

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20 Comments to “Milk and Tea Controversy”

  1. Nina K. Says:

    Moooorning JP ;-) ,

    i always made thoughts about milk or not. Green tea with milk is for me a nogo. Black tea would be good especially a chai tea. Maybe the spices enhance the absorbtion of the good tea ingredients? Besides that my hubby and i have trouble to find really fresh and only pasteurized milk (we don’t like homogenized and ultra high heated and ultra durable denaturated milk). Even the organic milk manufactures sell more and more these denaturated stuff! We don’t drink much fresh milk but we make a homemade youghurt and thats healthiest with fresh raw milk which isn’t easy available.

    JP – off topic now – i wish you and your wife and your families HAPPY NEW YEAR! I wish you a year full of joy – happyness – health – good ideas – inspiration for your wonderful blog here :-) - and that everything that you really want comes true :-) .

    Im so happy that i deteced your blog here, i enjoy the communication very much and im looking forward what 2010 will bring us.

    Greetings from “the far side” :-)
    Nina K.

  2. Sai Says:

    Dear JP:

    Excellent article! I always add milk (organic whole – a little) to tea. Also i have hibiscus tea (3 times a day) which keeps the blood pressure under control :) . What i have also noticed is that since having hibiscus tea, the post meal heartrate does not go up very high. While i am happy i was able to control that, i am not sucessfull with the blood sugar part :( . The post meal numbers (even a low carb) is not under control and i am still working the combinations that would do it for me and would keep you posted. Thanks again and HAPPY NEW YEAR :)

    Best Regards

    Sai

  3. JP Says:

    Thank you, Nina! :)

    I feel blessed and happy to have your contributions on this site. Your insights and suggestions always add a lot to these columns and I sincerely appreciate them!

    I also wish you and yours much joy, peace and wellness in 2010! :)

    PS – You may very well be correct about the bioavailability/spice connection. I’ve suspected that myself! It’s well documented that black pepper can enhance the absorption of a great many nutrients and phytochemicals. That suggests a good foundation for our hunch! ;)

    Be well!

    JP

  4. JP Says:

    Sai,

    That’s an interesting observation about the hibiscus tea! :)

    Have you started implementing Dr. Bernstein’s recommendations yet? I sincerely hope that provides at least one piece to your blood sugar puzzle. If not, we’ll keep on looking until we find a solution!

    I wish you and your loved ones a truly happy, healthful and peaceful new year! :)

    Be well!

    JP

  5. Sai Says:

    JP,

    Good Day!

    I have completed reading the book. He offers various insights into diabetes and those are good advise. He points more to insulin for the blood sugar control and that part requires courage!. I have noticed more hypergylcemic reactions after i started the multivitamins and i am going to do some test on trial and error now. Dr. Bernstein’s book does provide lots of useful information that every person who has diabetes should know (THANK YOU!!!). My problem JP is the dawn phenomenon (where the blood sugar after 2 hours after the dinner is OK but the fasting blood sugar is high). Since i start on the high number it is very difficult to control throughout the day. Once again a very happy new year to you and your family! and thanks much for your concerns and directions.

    Best Regards

    Sai

  6. liverock Says:

    JP

    Unfortunately a lot of the advantages of black tea with (or without) milk are negated by the high fluoride content in the tea.
    I recently contacted the largest black tea company in the UK to ask them the level of fluoride in one of their teabags, not really expecting them to reveal such confidential information.

    Surprisingly, they did reply and the level quoted was 1mg/bag, which means anybody drinking 3 cups a day is using up the so called “safe daily rate”, perhaps something to bear in mind.

    Black tea is also very good at keeping iron levels down, which can build up especially for heavy meat eaters and menopausal women who stop losing iron when menstruation stops.

    Some people here in the UK drink so much tea that they become anaemic and doctors have a hard time raising iron levels when they wont stop their tea drinking. It takes all sorts………

    May You and Your Family have a Happy and Prosperous New Year.

  7. JP Says:

    Sai,

    I’ll keep a special look out for information regarding that variety of blood sugar problem. I’ll post more as I learn more about it!

    In the meantime, keep on experimenting and please let me know what you discover! Your solution will surely be helpful for countless others!

    Be well!

    JP

  8. JP Says:

    Thank you, Liverock! :)

    I think both issues that you raise are important to consider. A good place to start is exactly how you mentioned – by contacting the manufacturer(s) of the tea you consume. I’ve also found most to be forthcoming with a general range of aluminum and fluoride in their tea products.

    Too little or too much iron can be harmful to be sure. If an inadequate iron status is found, I would certainly recommend avoiding tea – especially at the same time that iron supplements are taken. On the other hand, reducing iron levels can be health promoting in some instances. The key is to find out where you stand and to make choices accordingly. I know you’ve done this very successfully!

    Some natural health advocates, such as Bill Sardi, believe that higher than normal iron may be a significant health risk with regard to cancer and cardiovascular disease (via increased oxidative stress). In those instances drinking tea may be especially helpful.

    I wish you and your loved ones the same! Best wishes in 2010! :)

    Be well!

    JP

  9. kath Says:

    Hi, I know this is an old post but I hope you’re still checking comments. Firstly, thanks for the detailed summary,- very interesting.
    My question is, Would rice milk inhibit the anti-cancer properties of black tea? (This is the way I drink it). I guess caseins are not contained in rice milk but I was wondering if you know of any other compounds found in rice milk that may have a similar effect.

  10. JP Says:

    Hi Kath,

    I think it’s unlikely. Some rice milk is fortified with calcium (also abundant in cow’s milk), but this probably won’t affect the health benefits of tea, IMO.

    http://www.healthyfellow.com/771/coffee-calcium-controversy/

    Be well!

    JP

  11. jen Says:

    Hello, I stumbled upon this blog because I was trying to figure out if drinking tea with milk would inhibit iron absorption. I read that it might actually not inhibit iron absorption because tea has something that binds calcium. Is any of this true? I have anemia and with the cold weather I’ve been desperately craving tea, but i don’t know if I’m doing more harm than good by drinking it with milk. Plus I use condensed or can milk not the typical skim 2% or whole milk. Any ideas?

  12. JP Says:

    Hi Jen,

    Here’s what I would do: To be on the safe side, I would drink tea apart from iron-containing foods and supplements.

    On the other hand, drinking and/or eating Vitamin C rich beverages and foods with meals and supplements may improve iron absorption.

    http://journals.cambridge.org/action/displayFulltext?type=6&fid=7948464&jid=BJN&volumeId=105&issueId=01&aid=7948463&bodyId=&membershipNumber=&societyETOCSession=&fulltextType=RA&fileId=S0007114510003144

    http://journals.lww.com/jpgn/Fulltext/2010/05000/Orange_But_Not_Apple_Juice_Enhances_Ferrous.14.aspx

    Be well!

    JP

  13. Jae Herman Says:

    Wow! After an hour of reading various commentators including articles in the New York Times and by Dr. Andrew Weil, yours is the most specific and complete. Thank you so much. I am now convinced – mostly because of the health differences between the
    British public and Asians that drinking black tea with milk binds to the catechins and robs it of some of its antioxidant properties. However, it appears that there is at least one study that differentiated between the fat content in milk versus cream, and that the lower fat content in skim milk creates a more binding effect. I don’t know who performed that study.
    Anyhow, sorry for rambling on. Thanks again. If you see any studies which compare soy, almond, cream versus milk, I hope that you will write again.

  14. JP Says:

    Thank you, Jae!

    Be well!

    JP

  15. Jae Herman Says:

    Hey yourself. Thanks. Can you tell me/us about your comment at the end of your posting which stated that “organic tea is virtually free of protein.” How? thanks again. Jae

  16. JP Says:

    Hi Jae,

    I couldn’t find the comment you’re referring to. However, both conventional and organic tea is very low in protein. Small amounts of select amino acids (such as theanine) are present. However, they’re present in minimal quantities.

    Be well!

    JP

  17. Michael Says:

    Good article. (And I know I’m responding to something written years ago, but there are still comments coming in.)

    This was touched on, but it’s worth reiterating that it is important when reading these studies to differentiate between the findings that milk (of any sort) may not alter (or in some cases may even increase) blood/plasma antioxidant levels, and the findings that milk may dampen or negate the _beneficial effects_ of some of those antioxidants.

    In other words, while there is significant evidence to support the idea that milk is not _decreasing the quantity_ of antioxidants in the blood, there is strong evidence that it _alters the function_ of some of those antioxidants and prevents specific antioxidants from conveying specific benefits in the cardiovascular/circulatory system. So while the antioxidant levels are not necessarily decreased, some are not able to carry out their function. It’s not simply a matter of whether the antioxidants arrive, it’s whether once they arrive they’re capable of doing all of their good stuff, and it appears that with milk some of them can’t.

    This is actually a fairly common problem in medical research. Things that behave one way in the lab simply don’t behave that way in the body once they’ve gone through ‘the biological process’ of digestion/absorption, and interactions between other substances (natural or otherwise) can profoundly alter function, behavior and outcome.

  18. Michael Says:

    Another consideration is that milk alkalizes the tea and makes it less acidic in your mouth. If someone has sensitive teeth or has lost some enamel then it could be helpful. But as the article above says why not use almond or soy milk and get the same benefit without the potential loss.

  19. Arun Says:

    As always……..scientific bull…

    Don’t confuse yourself with facts.
    :-)

  20. JP Says:

    Hi Arun,

    I’m not sure if you’re trying to make a serious point. If so, please let me in on the facts you’re alluding to. I’d be happy to review and discuss them.

    Be well!

    JP

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