Doctor's Note

Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. Also, there are 1,686 other subjects covered in the rest of my videos--please feel free to explore them as well!

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  • JJ

    As posted on other pages, I’ve seen all these videos. I’m trying to synthesize all the information in my head into a coherent picture on how to eat. Here’s the problem:

    This video along with some others seems to say that eating any kind of protein, not just animal protein, blocks absorption of the wonderful nutrients from plants like cocoa, berries and *green tea*.

    There is also a video that says that our bodies will not absorb the good nutrients from greens (and my understanding is that green tea is like eating greens) unless we have some fat with the meal.

    In this video, you recommend using whole foods with fats (such as nuts) instead of fat-laden dressing in order to get the nutrients from greens into our bodies.

    But isn’t one of the things notable about nuts is that they have protein? And wouldn’t the protein block the absorption of the nutrients in greens? Do we really know the effects of nuts on absorption of nutrients in greens? And how much fat does one need to get the ideal absorption?

    It’s an honest question because eating greens is not easy for me. So, when I do it, I want to get the maximum impact. I’m working hard, with some minor successes, to build up a liking for kale. One recipe that I do like, probably because the sauce drowns out the kale, is a recipe that includes: kale, onion, and a yummy “creamy” dressing that is really a cashew base.

    So, I figure the cashews are giving me some fat in which to absorb the kale nutrients. But how much fat/cashews do I need per X amount of kale? And is it possible that the protein in the cashews turns around and simply blocks the nutrient absorption?

    Hope this gives you an idea of where my confusion is. I’m sure I’m making this more complicated than it needs to be. Any clarification you can provide would be appreciated.

    Thanks,
    - JJ

    • Michael Greger M.D.

      JJ, only dairy appears to have the ability to block the phytonutrient benefits of cocoa and berries (Nutrient Blocking Effects of Dairy). So it’s not all protein by any stretch (in fact it may not even be the dairy protein–we don’t know what’s in dairy that does that). So no need to worry about eating protein with your greens. And in terms of the carotenoid absorption (Forgo Fat-Free Dressings?) just a few cashews is all you need, especially if you release all their fat by blending them up. I’m sorry you got confused and I hope this helps clear things up!

      • JJ

        Dr Greger: Yes, your explanation helps a lot.

        My confusion is that I’m familiar with the concepts of things like “fat”, “protein” and “carbohydrate”. I do not have an understanding of what phytonutrient is. Or carotenoid. So, when I hear those words, I translate them into my head as “other stuff good for you”. Looks like I was getting confused because I was equating phytonutrient and carotnenoid. You definitely helped clarify!

        I clearly need to up my education level on for nutrition information so that I can process your videos better.

        Thanks again!!!

      • Vinnie

        Hi, doctor. I can’t really find this information online. What about if I consume both soymilk and green tea separately on the same day. Would soy milk still block the phytonutrient effects of the green tea, or is this block only effective when it’s mixed in the same cup? For example, let’s say I want to consume an oatmeal with soy milk at 8 in the morning and then drink a cup of green tea at 9? How far apart do the consumption times need to be to retain all the health benefits of green tea?

    • mlbinsf

      I drink about 1 cup of milk a day with my two coffees in the morning. I’m drinking the milk then I usually eat my breakfast about 10 min after drinking the coffee with milk, my breakfast is always oatmeal with blueberries and no milk. My question is how long between drinking the milk and eating the blueberries does the milk effect the nutrients in the blueberries. I don’t want to lose the nutrition of the blueberries but I really cant drink coffee without milk, so should I wait longer than 10 minutes between drinking milk and eating berries? I could just not eat berries with breakfast and maybe eat them later in the day but I really enjoy them in my oatmeal.

  • JJ

    I also want to point out that that kale dish that I like also has a can of garbanzo beans – more protein.

    One of the reasons I like that dish is that it seems to have it all: healthy protein, high-quality calcium-rich greens and good taste! But am I getting any good out of it?

    • Michael Greger M.D.

      The kale and cashews sounds yummy–you should post the recipe!

      • JJ

        Sure! I got the original recipe from:
        http://blog.fatfreevegan.com/2011/05/cosmic-cashew-kale-and-chickpeas-with-confetti-quinoa.html

        She has LOTS of really good “fat-free” (I think she means free of added processed fats) vegan recipes. I have modified her recipe to fit my tastes. For example, I omit the hot sauce, and I add mushrooms. I also changed up the process so that I can use the microwave instead of the stove top.

        The recipe is yummy. I highly recommend it to people who are trying to develop a taste for kale. While the author recommends putting it on quinoa (which would be very good), I think it works just great as a dish by itself.

    • Toxins

      All plants have complete proteins..no need to compliment for the 8 essential amino acids.

  • http://www.facebook.com/profile.php?id=505030063 Chris Grant

    I was thinking about this article recently, Does any non-daiy beverage have this effect? Has any more information been done to determine if it’s the protein, the fat, or some other compound that impedes the phytonutrient absorption?

    • Toxins

      Hello Chris!

      To quote Dr. Greger above, “only dairy appears to have the ability to block the phytonutrient benefits of cocoa and berries http://nutritionfacts.org/videos/nutrient-blocking-effects-of-dairy/ . So it’s not all protein by any stretch (in fact it may not even be the dairy protein–we don’t know what’s in dairy that does that). So no need to worry about eating protein with your greens.” Almond milk would be a safe non dairy substitute for tea, or with eating another nutrient dense meal. For right now the jury is out regarding what exactly blocks the nutrients.

  • Vallis

    Who does the voice on the videos? The guy cracks me up and does an amazing job of keeping me listening and engaged.

    SOY. I heard too much soy is not good for men because of the supposed estrogen in it. I heard that allot of men started to grow breasts in the 90′s who were drinking tons of soy. Is there any science supporting this? It completely put me off soy products when I heard/read this.

    I am not sure if this was the right video to post this question. But there it is.

  • http://www.facebook.com/tzdrojewski Tom Zdrojewski

    I know you said it’s best to drink it straight, but is there any data yet about coconut milk-based creamer or other non-dairy non-soy creamers?

    • Toxins

      Tom, we should do our best to stay away from coconut products in general. Its a very high saturated fat food.
      http://nutritionfacts.org/videos/is-coconut-milk-good-for-you/

      • http://www.facebook.com/tzdrojewski Tom Zdrojewski

        That is disappointing. Thank you.

        • Toxins

          Sorry! Coconut water is fine though. Perhaps you can add coconut water to your soymilk?

          • http://www.facebook.com/tzdrojewski Tom Zdrojewski

            I do like coconut water. But with creamer it’s mostly about the texture for me. Same thing with coffee. I was looking to replace dairy-based creamer. Soy milk, almond milk, creamers based on those, etc just don’t add the right texture. I imagine coconut water wouldn’t either.

          • http://www.facebook.com/tzdrojewski Tom Zdrojewski

            I do like coconut water. But with creamer it’s mostly about the texture for me. Same thing with coffee. I was looking to replace dairy-based creamer. Soy milk, almond milk, creamers based on those, etc just don’t add the right texture. I imagine coconut water wouldn’t either. Thank you for the suggestion, though.

        • Toxins

          Well what about this coconut “flavored” creamer. Based from rice milk and soy milk and “natural” flavors.
          http://www.naturesflavors.com/index.php/flavored-coffee-beans-organic-flavored-coffee-beans/organic-non-dairy-coffee-creamers-powder/organic-coconut-non-dairy-coffee-creamer-low-fat-kosher-vegan-gluten-free.html

          I approve of the ingredients (from face value) but id just need a confirmation from the nutrition label.

  • NBMaggie

    Re: More Texture to Faux Creamer/Coffee: I’ve been making my own soymilk for years now and a post by Bryanna Clark Grogan at http://veganfeastkitchen.blogspot.ca prompted me to add 1/4 cup old-fashioned large flake oats to my basic soymilk recipe. The results were delicious in my morning soy latte – very creamy. I’m not sure how you’d get this effect with commercially prepared soymilk. Mind you, none of this addresses the issue raised by Dr. Greger about soy and its effects.

  • Harel B

    I sometimes use ‘micro’ amounts of soymilk, as in, less than 1oz in a cup that holds 20 ounces of tea

    So….to be most useful, research should show us not one bar for “adding soymilk” but many depending on how much, proportionately.

    If 20oz tea plus 1oz soymilk causes as much “suppression” as a combination of  15oz tea plus 6 oz soymilk, then I’d stop using it entirely…but if it’s a very graduated effect, then those of us who enjoy such small amounts (just enough to just barely ‘cloud’ the drink a tiny bit, would maybe want to continue

    • gary bocan

      I agree, that’s what i do too. I try to drink tea without anything, but sometimes it’s just too bitter and i need to add a little almond/soy milk. I just add the smallest amount necessary to cover up some of the bitterness.

  • Stephen Mayer

    What about almond milk?

    • Toxins

       Almond milk should not be assumed to have the same affect as soy milk. These foods have very different phytonutrients and protein ratios.

      • Vin

        Hi, Toxins. I can’t really find this information online. What about if I consume both soymilk and green tea separately on the same day. Would soy milk still block the phytonutrient effects of the green tea, or is this block only effective when it’s mixed in the same cup? For example, let’s say I want to consume an oatmeal with soy milk at 8 in the morning and then drink a cup of green tea at 9? How far apart do the consumption times need to be to retain all the health benefits of green tea?

        • Toxins

          I honestly do not know. I would assume when consumed at least 2 hours apart there should be no cause for concern. This is how long typical stomach emptying takes.

          • http://SmartDreams.net Gayle Delaney PhD

            How about the effects of Soy milk on Coffee Lattes? Almond milk is just not as delicious to me. Is there anything we can mix soy milk with sans losing nutrient benefits?

          • Toxins

            Not that I know of Gayle, but I don’t think that you should worry about it in that situation. Soymilk itself has nutritional value and masking some coffee antioxidants is not really a big deal.

          • http://SmartDreams.net Gayle Delaney PhD

            Thank you for this, Toxins, and for all your informative and clarifying posts. You are treasure!

            We add ½ tsp or so of a mix of spices, cinnamon, cardamon, cloves, turmeric, pepper, and ginger to our coffee with our soy milk, froth it up, and YUM YUM. Tastes a bit like “chai coffee.” Someday I may go to almond milk, but I find it chalky and love the richness of soy after a lifetime of non-fat and 1% cow’s milk!
            After decades of loving green tea, just before going WFPB I suddenly began to hate it. Thanks to Dr. Greger, we discovered the even healthier and so beautifully ruby-colored hibiscus tea and find it delicious with some Truvía (erythritol 50+% and stevia).

          • http://SmartDreams.net Gayle Delaney PhD

            I love your practical and non-dogmatic approach, Toxins! Thank you. So! Antioxidant vs phenol suppression. Blueberries and mangos with a date in our favorite Vitamixed soy ice cream. Soy in tea, milk, coco. Trade offs? In the context of a 100% WFPB diet, it seems OK even if we would be better off or safer using almond milk. We buy our Almond milk and it has more salt than our brands of Soy milk. How to gauge all the trade-offs? (BTW Whole Foods unsweetened soymilk has almost twice the sodium of Trader Joe’s and of Wildwood brands.

          • Toxins

            Thanks Gayle for the compliments. I would agree with your tendency, that “In the context of a 100% WFPB diet, it seems OK even if we would be better off or safer using almond milk.” These drinks are not your primary calorie source and even if they were, they are healthy nonetheless. Worrying about these minor details is not relevant in the big picture, as going WFPB is the best thing you can do for yourself and your family. Enjoy your soy milk infused drinks!

  • gary yrag

    The confusion is something i at one time shared with “JJ,” until i did some academic research on tea. The main chemicals in tea that we do *not* want blocked is a group called “catechins” (there are several in tea, eg, EGCG & EGC). Research was done to compare green tea catechin absorption on an empty stomach versus with food. The human subjects were given either some carbs, in the form of bread of muffins, to accompany their tea, or just drank the tea on an empty stomach (in the morning after waking). The researchers found that the catechin absorption into the subjects’ blood stream was much higher when tea was taken on an empty stomach. Another study also found that tea catechin absorption is further enhanced when ingested with something acidic, like lemon juice. (I experienced nausea when i tried to drink green tea on an empty stomach, and especially with lemons. However i experience considerably less nausea when i use white tea leaves instead).This however contrasts with the carotenoid antioxidants found in high levels of many colored and green leafy vegetables. These carotenoids are fat soluble and require some fats to go with the veggies, as i learned from Dr Greger’s video also. 

    JJ, if you happen to see this post and would like links to the 2 research articles on tea, i would be happy to provide them to you.

    • gary bocan

      So, long story short: try to drink tea on an empty stomach. It seems that any kind of food, not just tea, will affect catechin absorption. The exception is acidic foods, eg, lemons. Acidity actually seems to help.

    • The Ironist

      Yes, would you please cite those articles? Eating bread increases cocoa catechin bioavailability, so it would be interesting to see where eating bread decreases tea catechin bioavailability. Thank you.

      • gb

        Yes the first paper is titled “Effects of Dosing Condition on the Oral Bioavailability of Green Tea Catechins after Single-Dose Administration of Polyphenon E in Healthy Individuals” and is in the June 15, 2005 issue of the journal Clinical Cancer Research. It is available to read for free online; try google search or enter this into google: http://clincancerres.aacrjournals.org/content/11/12/4627.full
        In the “Conclusions” portion of the abstract (ie, end of abstract), it says ” We conclude that greater oral bioavailability of free catechins can be achieved by taking the Polyphenon E capsules on an empty stomach after an overnight fast. Polyphenon E up to a dose that contains 800 mg epigallocatechin gallate is well-tolerated when taken under the fasting condition. This dosing condition is also expected to optimize the biological effects of tea catechins.”
        Polyphenol E is a pill that has standardized amounts of tea catechins. The paper explains that these pills were provided by the National Cancer Institute, but i also did a little more reading on the internet and found that it’s made by a japanese company that makes these pills available to institutions for research (apparently Polyphenon E is the preferred means of studying standardized quantities of tea catechins, as opposed to extracting the substances from tea leaves oneself).
        I recommend reading the whole paper, even though it’s a bit lengthy.
        I will have the other 2 papers for you by the end of this weekend; i need to search through my files and try to find them.

        • gb

          The paper above that i’m referencing is however not the same one that i alluded to in my first post above (from one year ago). That’s one of the papers i’m going to look for.

        • The Ironist

          Thank you. Fasting seems to increase green tea catechins overall 3.5 fold and may possibly decrease ECG and EC catechins. The biological processes discussed in Results suggest that taking green
          tea catechins fasted with lemon juice should enhance bioavailability by
          maintaining low pH in the small intestine and by maintaining supportive antioxidants (esp. ascorbic acid) without
          substantially activating the
          mechanisms that decrease tea catechin absorption: slowing digestion rate or increasing bile release. Fat and protein probably decrease catechin absorption, but carbohydrate (sugar and bread) may or may not increase tea catechin absorption.

          Is there any reason carbs should have different effects on tea and cocoa catechins? Interestingly, googling “cocoa milk catechin bioavailability” suggests milk protein impairs tea catechin absorption but not cocoa catechin absorption.

          • gb

            Another study that i latched onto was regarding the use of ascorbic acid vs. citric acid in preserving the tea catechins’ stability; this was however just by test tube (in vitro), and not tested on human subjects. The study is “Stabilizing Effect of Ascorbic Acid on Green Tea Catechins,” in the June 1998 issue of the Journal of Agricultural and Food Chemistry. It’s available online free, via google search or at: http://dx.doi.org/10.1021/jf971022g
            The above study echoes what you’ve stated, which is that ascorbate appears to help preserve the tea catechins, presumably in the gut, although we don’t know for certain since this was just by test tube. And since the citric acid didn’t preserve the catechins, we know that the pH of the ascorbic acid is not the only factor at work; it may be that the ascorbic acid acts as an antioxidant to help preserve the catechins. So i’ve taken to taking lemon juice with my tea, when possible. I’ve even tried consuming capers along with my tea, since capers have high levels quercetin, which along with the ascorbate, may aid in preserving the catechins (however i can’t find the study that suggests the quercetin in the lemons may be responsible, so i guess i shouldn’t speculate here). For me personally, i’ve recently enjoyed putting freeze-dried berry powder (different kinds of berries) into my tea, because it adds to the health properties and helps mask the tea’s bitter taste, and so i think that the carbs from the berry powder may have an effect on catechin absorption, but whether it assists or hinders i have no idea.
            I don’t know what the answer is to your question about why tea being impaired by certain substances such as milk proteins, and yet cocoa catechins are not impaired. I did read that they have different flavonoids– cocoa having “procyanidins” and “flavan-3-ols,” while tea has the trio of “EGCG,”, “EGC,” and “ECG” (hope i spelled those right), so maybe that’s the primary reason for the difference.

          • William Dwyer

            Mauro Serafini, PhD, of Italy’s National Institute for Food and Nutrition Research in Rome, reports:

            “Our findings indicate that milk may interfere with the absorption of antioxidants from chocolate … and may therefore negate the potential health benefits that can be derived from eating moderate amounts of dark chocolate.”

        • http://SmartDreams.net Gayle Delaney PhD

          Any updates on soy milk blocking this and that?

          • gb

            No updates on that, although i wouldn’t worry about it too much. Soy has its own benefits, especially if homemade. I’m sure Dr Greger will update us eventually if a study appears on the subject. If you are concerned about interference by soy but don’t want to give it up with your tea, try mixing it 50/50 with almond milk– that’s what i do and i still manage to get some of the soy flavor that way.

            You can possibly improve the absorption of the tea catechins (whether using soy or not) by adding having some vitamin C & xylitol sweetener with your tea. According to this study, it increases gut absorption by 10x, versus drinking tea plain. To quote from the “Results and Discussion” section (web link below):

            “The intestinal uptakes of total catechins in green tea with xylitol/citric acid and xylitol/vitamin C were approximately 6 and 11 times, respectively, higher than that in green tea only. Meanwhile, the addition of sucrose and glucose to green tea with citric acid did not give any significant effect on intestinal uptake of total catechins, though sucrose and glucose were significantly effective on catechin uptake in green tea with vitamin C.

            http://www.sciencedirect.com/science/article/pii/S0963996911005928

  • Sharon McRae

    Does adding nut/seed milk, like hemp/almond, also interfere with absorption of antioxidants, particularly in green tea?  

    • Toxins

      No, it appears that soymilk and dairy are the only perpetrators that we know of.

      • Debraapples

        Thanks for this answer. How do we know this? Have more studies been done? Would love to know.

        • Toxins

          The protein profile may be at play here, and as soy has a very similar protein profile to that of animal products, including milk, we can assume that almond milk and others would not have the same effect. Of course this is speculation.

  • Brentandliza

    So if I am putting soy milk in my spinach/blackberry smoothie I’m not getting the phytonutrients?  So sad!  I like almond and rice milk but my kids like soy, so that’s what I’ve been using…

  • tel-nir

    If I put soy milk in a fruit shake containing amla powder, will it negate the effect of the antioxidants or any other good value of it?
    If it does, how much time do I need to wait between soy milk intakes before I drink the shake (without soy milk)
    Thanks!

  • My975

    Hello Dr. Greger,

    Would you please present information or effects with carrageenan found in soymilk and alternative dairy products? I am reading that it is harmful and should be avoided. Thank you!!

  • Sky

    Would soy milk also negate positive effects of other foods/drinks, like muesli, porridge, smoothies etc.?

  • Stefanie

    Is there any information out there on whether other milk substitutes such as rice-, hazelnut- or almond milk have the same effects as cows milk and soy milk?
    I don’t actually put any milk in my tea anyways. What I would just like to have is a bowl of oatmeal with some sort of milk and a cup of green tea for breakfast. Surely, there must be some way to do that without losing the tea’s benefits?

    • Toxins

      There is not currently any evidence showing that these other milks suppress the antioxidants like dairy or soy. I would doubt that this evidence would be found as we can hypothesize that this binding of nutrients is due to the protein structure.

  • Mark Hazell

    How does soy milk compare to almond milk (store bought)? I try not to drink soy milk because I dont really like the taste and prefer almond milk so I just drink that. But what if I add almond milk to berries or tea? Does it block the nutrients?

  • Tobias Brown

    Well there goes my antioxidant chai with rooibos tea each morning, which uses soy milk. What’s the point if the soy milk likely blocks the uptake… So, which “milk” has a green light?

  • The Ironist

    Ironically, I have been:
    * eating tofu with salads (black beans, bell peppers, green leafies, berries)
    * adding cocoa powder to Greek yogurt

    Implications of the protein argument due to their protein digestion times:
    * consuming soy protein? wait 3-5 hours before consuming antioxidants?
    * consuming dairy/casein? wait 6-8 hours before consuming antioxidants?

    Questions outstanding:
    * What class of substances exactly block antioxidant absorption
    * What is the exact time lag after which one can eat antioxidants
    * Do only milk and soy (milk) block antioxidant absorption
    * Does this effect only block antioxidant absorption from cocoa and berries
    * Wouldn’t this casein clumping effect not defeat but only delay the digestion and absorption of these antioxidants

    Sadly,
    for now, it appears the only conservative thing we can do is limit milk and soy to
    perhaps the last meal of the day and try to eat antioxidant rich foods
    throughout the day, hoping some of them get absorbed.

  • Richard Crandall

    Does soymilk block the phyotnutrients in cocoa? Or should I switch to something like almond milk?

    • Toxins

      For now, we can assume that it does. Switching to almond milk may be a smarter choice to preserve the phytonutrients.

  • Sebastian Tristan

    I often add cocoa powder, cinnamon and clove to my tea. Do you think these ones could affect the phytonutrient effect of tea as well?

  • Thule

    Please some clarification, this study apparently contradicts a previous one:

    http://nutritionfacts.org/video/the-healthiest-beverage/

    “This year from the British Nutrition Foundation, does adding milk remove the benefits of your daily cuppa tea? The answer is yes. It seems that cow proteins bind up all the good phytonutrients. None of the soy, rice or nut proteins in plant based milks have that same nutrition cancelling effect. ”

    Notice that last part — None of the soy, rice
    or nut proteins in plant based milks have that same nutrition cancelling effect.

    Unfortunately I cannot access the research paper in that study:

    http://onlinelibrary.wiley.com/doi/10.1111/j.1467-3010.2007.00636.x/abstract

    So I don’t know what method they used, vs the method used in this study:

    M. Lorenz, K. Stangl, and V. Stangl. Vascular effects of tea are suppressed by soy milk. Atherosclerosis, 206(1):31-32, 2009.

    In this one we know thanks to Dr. Greger, that it was done “in vitro, in a petri dish. We don’t know if this translates into actual people”

    Anyone with access to the first study can comment? Given that most of us use soymilk and tofu etc, the fact that the soy protein could be binding up pythochemicals, :S

    But I noticed that Dr. Greger uses soymilk in his smoothies, and recipes, and also tofu, which means that he isn’t too concerned about the possibility that it might be blocking other phytochemicals beyond the ones in tea?

  • Carlo

    The study was in vitro, and not even on human cells: they used bovine aortic endothelial cells (BAECs). This is quite far from being conclusive.

  • EmilyVegan

    Dr. Greger, I love your videos and I am so grateful for them – thank you! However, I have to admit that this information made me sad… I drink tea with soymilk everyday! Is there an update to this information? Perhaps a study done with humans?

  • Larry Hays

    Sounds like they used commercially made soy milk in there test ( we make our own) there is allot of other junk in that milk besides soy . Should we avoid eating other soy products when we drink green tea?