Benefits of Blueberries for Blood Pressure May Be Blocked by Yogurt

Benefits of Blueberries for Blood Pressure May Be Blocked by Yogurt
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Researchers try to tease out what’s in dairy that interferes with the health benefits of berries and tea.

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Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

A trio of Harvard studies that followed more than 100,000 women for more than a decade found that those consuming the most anthocyanins (the brightly-colored pigments found in berries, like blueberries and strawberries) “had an 8% reduction in [the] risk of” developing high blood pressure. And the group consuming the most every day were only eating about six strawberries’ worth, or even just 11 blueberries—a tenth of a cup.

But, maybe the biggest berry-eaters just happened to have other healthy habits, and that’s the real reason they did better? After all, you’re probably more likely to sprinkle blueberries on oatmeal than on bacon and eggs. But, they controlled for whole-grain intake, and fiber and salt and smoking and exercise and a bunch of other things, and the berry benefit still remained. But, you don’t know for sure until you… put it to the test.

“A Randomized, Double-Blind, Placebo-Controlled Clinical Trial,” and, the title gives away the thrilling conclusion: “Daily Blueberry Consumption Improves
 Blood Pressure.” How can you do a double-blind trial, though, with a food? How can you convincingly create a fake placebo blueberry? They used whole blueberries—about a cup worth, but powdered them, versus a look-alike placebo powder, which had the same amount of sugar and calories as the real blueberries, but without the actual blueberries. Those in the placebo control group: no real change over the eight-week study. They started out 138 over 79, and ended up 139 over 80, whereas the real blueberry group fell from 138 over 80 to 131 over 75—a significant drop. Now, 131 is still too high. You’d like to see at least down to 120 or even 110, so blueberries alone may not cure you. However, the fact that you could get a clinically significant improvement in a killer disease by just adding a single thing to your diet is pretty impressive.

Is more better? What about twice the dose, more like two cups of fresh blueberries a day? Same kind of significant drop, but didn’t seem to work any better. So, one cup may do it. Even less may work; it’s never been tested.

Overall, there have been five interventional studies to date on the effects of blueberry supplementation on blood pressure. Put all the studies together and the results do not show “any clinical efficacy”—wait, what?! I just showed you two studies where there was this gorgeous effect. Have I been cherry-picking studies, or rather berry-picking studies? Well, if you look closely at the studies, “the blueberries in the two studies [I showed you that] detected a significant effect [were] prepared with water.” They just mixed the blueberry powder with water. However, the blueberries in the non-significant effect studies were prepared with yogurt and skim milk-based smoothies.

If you remember my blast-from-the-past video from like eight years ago, the absorption of berry nutrients can be blocked by dairy. Mix strawberries with water, and you get a nice peak in strawberry phytonutrients in your bloodstream within hours of consumption. But, if you instead go for strawberries with cream—mixing the same amount of strawberries with milk instead— significantly less makes it into your system. “The inhibitory effects of milk [are thought to] be due to [the] interaction [between the berry pigments] and milk proteins.” Yeah, but does the same thing happen with blueberries? Let’s find out.

Hard to maintain the suspense when the title just gives it away. But, indeed: the “[a]ntioxidant activity of [blueberries] is impaired by…milk.” Volunteers ate a cup and a half of blueberries with water or with milk, and the milk blocked the absorption of some phytonutrients, but not others. So, did it really matter that much? Here are the spikes in the bloodstream after blueberries with water, and here’s how much is absorbed with milk. Okay, so less. But, check out what happens to the total antioxidant capacity of your bloodstream. Eat blueberries alone, with water, and the antioxidant power of your bloodstream shoots up within an hour, and remains elevated five hours later. Okay, so with milk, you’d be thinking there’d be maybe less of a bump, right? You can say that again; not just less, but less than where you started from­. You just ate a whole bowl of blueberries and ended up with less antioxidant capacity in your body, because you ate them with milk. No wonder mixing blueberries with yogurt or milk may abolish the blood-pressure lowering benefits.

Interestingly, “full-fat milk” may inhibit nutrient absorption the most, similar to what one finds adding milk to tea: twice the reduction in in vitro antioxidant values with whole milk compared to skim milk, which is weird because we always thought it was the milk protein that was the culprit. This suggests there may be some nutrient-blocking involvement from the dairy fat as well.

Please consider volunteering to help out on the site.

Image credit: Veganbaking.net via Wikimedia. Image has been modified.

Motion graphics by Avocado Video.

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

A trio of Harvard studies that followed more than 100,000 women for more than a decade found that those consuming the most anthocyanins (the brightly-colored pigments found in berries, like blueberries and strawberries) “had an 8% reduction in [the] risk of” developing high blood pressure. And the group consuming the most every day were only eating about six strawberries’ worth, or even just 11 blueberries—a tenth of a cup.

But, maybe the biggest berry-eaters just happened to have other healthy habits, and that’s the real reason they did better? After all, you’re probably more likely to sprinkle blueberries on oatmeal than on bacon and eggs. But, they controlled for whole-grain intake, and fiber and salt and smoking and exercise and a bunch of other things, and the berry benefit still remained. But, you don’t know for sure until you… put it to the test.

“A Randomized, Double-Blind, Placebo-Controlled Clinical Trial,” and, the title gives away the thrilling conclusion: “Daily Blueberry Consumption Improves
 Blood Pressure.” How can you do a double-blind trial, though, with a food? How can you convincingly create a fake placebo blueberry? They used whole blueberries—about a cup worth, but powdered them, versus a look-alike placebo powder, which had the same amount of sugar and calories as the real blueberries, but without the actual blueberries. Those in the placebo control group: no real change over the eight-week study. They started out 138 over 79, and ended up 139 over 80, whereas the real blueberry group fell from 138 over 80 to 131 over 75—a significant drop. Now, 131 is still too high. You’d like to see at least down to 120 or even 110, so blueberries alone may not cure you. However, the fact that you could get a clinically significant improvement in a killer disease by just adding a single thing to your diet is pretty impressive.

Is more better? What about twice the dose, more like two cups of fresh blueberries a day? Same kind of significant drop, but didn’t seem to work any better. So, one cup may do it. Even less may work; it’s never been tested.

Overall, there have been five interventional studies to date on the effects of blueberry supplementation on blood pressure. Put all the studies together and the results do not show “any clinical efficacy”—wait, what?! I just showed you two studies where there was this gorgeous effect. Have I been cherry-picking studies, or rather berry-picking studies? Well, if you look closely at the studies, “the blueberries in the two studies [I showed you that] detected a significant effect [were] prepared with water.” They just mixed the blueberry powder with water. However, the blueberries in the non-significant effect studies were prepared with yogurt and skim milk-based smoothies.

If you remember my blast-from-the-past video from like eight years ago, the absorption of berry nutrients can be blocked by dairy. Mix strawberries with water, and you get a nice peak in strawberry phytonutrients in your bloodstream within hours of consumption. But, if you instead go for strawberries with cream—mixing the same amount of strawberries with milk instead— significantly less makes it into your system. “The inhibitory effects of milk [are thought to] be due to [the] interaction [between the berry pigments] and milk proteins.” Yeah, but does the same thing happen with blueberries? Let’s find out.

Hard to maintain the suspense when the title just gives it away. But, indeed: the “[a]ntioxidant activity of [blueberries] is impaired by…milk.” Volunteers ate a cup and a half of blueberries with water or with milk, and the milk blocked the absorption of some phytonutrients, but not others. So, did it really matter that much? Here are the spikes in the bloodstream after blueberries with water, and here’s how much is absorbed with milk. Okay, so less. But, check out what happens to the total antioxidant capacity of your bloodstream. Eat blueberries alone, with water, and the antioxidant power of your bloodstream shoots up within an hour, and remains elevated five hours later. Okay, so with milk, you’d be thinking there’d be maybe less of a bump, right? You can say that again; not just less, but less than where you started from­. You just ate a whole bowl of blueberries and ended up with less antioxidant capacity in your body, because you ate them with milk. No wonder mixing blueberries with yogurt or milk may abolish the blood-pressure lowering benefits.

Interestingly, “full-fat milk” may inhibit nutrient absorption the most, similar to what one finds adding milk to tea: twice the reduction in in vitro antioxidant values with whole milk compared to skim milk, which is weird because we always thought it was the milk protein that was the culprit. This suggests there may be some nutrient-blocking involvement from the dairy fat as well.

Please consider volunteering to help out on the site.

Image credit: Veganbaking.net via Wikimedia. Image has been modified.

Motion graphics by Avocado Video.

Doctor's Note

What about soy yogurt? Doing a video about that, too—stay tuned. If you’ve not yet subscribed, sign up here (for free, like everything else through NutritionFacts.org).

What else can berries do? Check out:

But wait; if we don’t eat dairy, what about our bones? See Is Milk Good for Our Bones?

For a whole diet approach to combat high blood pressure, see How Not to Die from High Blood Pressure.

If you haven’t yet, you can subscribe to my videos for free by clicking here.

115 responses to “Benefits of Blueberries for Blood Pressure May Be Blocked by Yogurt

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  1. The great White Poison. One of the easiest things I ever quit, don’t miss, and couldn’t even drink it on a dare now.

    Love my berries.

      1. I saw on an earlier video that soy milk caused the same impairment. I suspect it is most liquid protein or protein dissolved in fluid that might be the culprit. It could also be merely a fraction of the protein like a certain amino acid. Who knows but I’m not taking any chances. No liquid that has protein in it for at least 4 hours before or later. I suspect solid forms like flax or walnuts or beans for that matter wouldn’t effect it. It takes too long for them to break down into their amino acid constituents so therefore it seems to be not long enough for the anthocyanin to mingle with eventual liquid protein. I wish there was one more study to confirm all this….just using logic at this point.

        1. That’s odd, I thought I commented on this but I’m not seeing my comment.

          Bob, there was no video indicating that soy had the same effect. The video you must be thinking of is the one about dairy interfering with tea antioxidants and soy milk was shown to as well. Apparently that was a Petri dish study, too, so hopefully more insight will be shed on that.
          I think 4 hours is unnecessarily extreme, personally. Even if liquid protein, as you say, did interefere, I think if our bodies were that sensitive then almost no one throughout history would have received the benefits of berry antioxidants which is not the case. Even in Dr. Greger’s last video on blueberries and arterial function, one of the moderators commented that they had combined the blueberry powder with some form of dairy (going on memory) yet they still got those significant results so I actually find it a little confusing. Mind you I’m not suggesting dairy doesn’t block antioxidants in berries and other things, I think that’s fairly well established.
          I personally doubt plant protein would have the same effect, but still wonder and especially wonder about soy. But one thing that comes to mind is the food combining study where they combined raspberries with adzuki beans ( I believe it was) and found that total antioxidant activity significantly increased due to some sort of synergistic effect. If those adzuki beans were made into a milk I don’t see how that would have a different impact.

          1. Hi Shaylen…..You’re right it was about dairy interfering with tea antioxidants and soy milk was shown to as well. But after this recent video I’m making a logical safety play that might actually be unsupportive by science. Problem is there’s so few studies or even attempted studies due to the non profit nature of such. I’m grateful for what has been done and it has actually been part of my lifestyle now to consume my own ground tea cocoa and a blend of various spices including turmeric. I follow that up with various berries and trehalose. For a snack, a soup made with broccoli kale pepper onion tomato soup. I call them the perfucutories like what gymnasts and other disciplines have to do before they embark on their own creative efforts. I want to make sure I eat them and I want to make sure I guarantee that I eat them and get them out of the way and then eat foods that are aid in a before dinner workout like beans soy milk oatmeal or whatever grains and beans I like. It did start out to avoid any possible negation for tea antioxidants but after the new video, I can’t be sure what more is possibly negated if any. Like going down a dark alley where only one crime is proven to be committed repeatedly like loan sharking and a thumb breaking goon enforcer which usually requires a person asking for the loan and then can’t pay if off in the first place. I don’t know what else is going on there and so I just prefer to not go there.

        2. well, crap, there goes the idea of adding almond milk and vegan protein powder to my smoothies.. or I eat the berries the other half of the day instead, but blech.. what sweetener should I cut the veggie smoothie without berries? I guess I could eat them twice a day. Hmm.. i really want to see a study about almond/soy milk and berries to be sure it’s the protein and fat and not something else about the animal product (taking into account S’s comment below that this soymilk-berry interference might not exist).

  2. I quit drinking bovine breast milk (and all dairy) about 6 years ago. Humans don’t even drink their own breast milk past age 1 or so. Yet people have been sold on the idea that we should drink the breast milk from an animal of a different species. For what … the calcium? HaHaHa! That’s what the power of a big money lobby can do … slowly kill you.

    1. What component of the milk is the culprit?
      Does raw milk dairy behave the same as pasteurized milk (I can safely eat the former but the latter gives me asthma)
      And is the effect the same if you eat blueberries and dairy (well aged cheese) in different meals?

      1. I would imagine raw and pasteurized would have the same effect. I’d also imagine that the effect would only occur if the dairy and berries were infested in the same meal, but good question. Even so, though, I would imagine that snacking on cheese between meals would use up a lot of antioxidants in your body, so maybe it would still have an impact but in a less direct way.

      2. I have the same question. The raw milk, grass-fed folks are going to chalk this up to ‘conventional, pasteurized’ dairy.

  3. I make a fruit salad with berries, banana, ground flax seed and Kite Hill Almond Yogurt. It’s made from almond milk. It is really good. They make a plain variety too.

    1. The problem with all store-bought yogurt, both dairy and plant-based, is that they contain added sugar, usually a lot of it. I used to eat plant-based ice cream and yogurt but quit because of the issue of sugar.

      1. Kite Hill has a plain, no sugar variety. This is good, add your own fruit. It’s just an option for those that want to avoid dairy and still like the creamy texture and probiotics in yogurts.

      1. Yes! The soy question is finally being addressed!
        I’m hoping it does not have a similar effect as soy blends so nicely with berries!

    1. Dr Greger answered the question of soy milk blocking the benefits of green tea in this video https://nutritionfacts.org/video/soymilk-suppression/ There are other mentions of it in green tea videos.

      As an aside, the price of bleberries (berries in general) is riculously high here, and not worth a couple of points on the blood pressure scale. Fortunately, adhering to a healthy plant based diet and getting lots of exercise plus taking time for meditation daily works wonders in lowering BP effectively. Thank you Dr Greger and team.

        1. Yes they’re pretty expensive here too which is why I rarely get fresh berries :( But I consume frozen berries daily and they’re actually more fresh if frozen right after harvesting. Still, I love snacking on fresh berries, wish prices would go down.

      1. Frozen blueberries sprinkled on green salad taste great! They melt by time they are consumed–and keep their shape!
        Ditto frozen raspberries.

        I’ve also been experimenting with berry concentrates in salad dressings.

      2. Argh! Been drinking black tea with soy milk for a couple of years, thinking I’ve been bathing my body in phyto-nutrients, but according to the video, no. Thanks for the info. Time to man up and drink my tea straight up.

    2. An earlier video says soy milk nullifies it also. I suspect it is most liquid protein or protein dissolved in fluid that might be the culprit. It could also be merely a fraction of the protein like a certain amino acid. Who knows but I’m not taking any chances. No liquid that has protein in it for at least 4 hours before or later. I suspect solid forms like flax or walnuts or beans for that matter wouldn’t effect it. It takes too long for them to break down into their amino acid constituents so therefore it seems to be not long enough for the anthocyanin to mingle with eventual liquid protein. I wish there was one more study to confirm all this….just using logic at this point.

      1. Bob, I don’t believe there is any video on this site saying that soy acts the same. I believe you’re thinking of soy milk interefering with tea antioxidants (which apparently was a Petri dish study which I think is good to keep in mind but still would not mix soy with tea). And where are you getting your 4 hours idea? Sounds extreme and kind of going against nature as in if berry antioxidants were that sensitive, I don’t think most throughout history would have received their benefits and that’s simply not the case.

  4. What about plant based fat? Does that have a negative effect on nutrient absorption from berries? I typically will make a smoothie with either fresh or frozen organic berries and add coconut flesh for good fat, along with coconut water and a little vanilla extract, as well as some leafy greens, and have a delicious and what I’m thinking is a very nutritious smoothie. Is the problem fat in general, or just dairy-based fat? And what is additionally confusing is that fat is shown to enhance absorption of nutrients from vegetables.

    1. I wonder too. My husband eats the same thing everyday: cooked whole oat groats with 1/2 c. fresh blueberries, ground flax seed, chopped walnuts, then he covers it with homemade almond milk. (A lot of plant-based fats!) Darn blueberries are the most expensive item in the list and he won’t eat frozen. Hope we’re not wasting $$ thinking he’s getting optimal nutrition. He says this is his favorite meal of the day!

      1. I personally doubt that other plant protein and fats block the effect, but I’m still desperately looking forward to Dr. Greger’s next video on this and hope he talks about more than just soy.

    1. This to me is very, very important question. I all but stopped milk and dairy, but have been using Almond Milk in my smoothies and oatmeal.

  5. https://www.womansday.com/health-fitness/wellness/a54037/yogurt-blood-pressure/

    Eating Yogurt Could Be the Key to Reducing High Blood Pressure:

    ke low-fat milk and cheese are already known to reduce the risk of high blood pressure in at-risk adults, say the researchers, but this is the first to look at the independent effect of yogurt alone. In fact, the team of doctors found a positive link between daily servings of milk and cheese and lower risk of high blood pressure, but according to Buendia, this was not as strong as the effect of yogurt.

    1. Greg: paragraph 2, line 2 states that this is a new study funded by the National Dairy Council. I guess if you really don’t want to give the stuff up, you can always convince yourself that there’s absolutely no conflict of interest with this study what so ever. SMH

      1. Nancy,
        Thanks for finding and exposing this conflict of interest! This technique of “suppliers funding biased research studies” is so deceptive. And the news media will tout these studies without checking for bias. It’s no wonder the general public is confused.

    2. What did the yogurt etc replace in the diet? If it replaced, meat, burgers, full fat dairy etc etc, then it may well have reduced blood pressure RELATIVE to those foods. This is a pretty standard technique used in industry funded study – compare your product to ones that are known to be even worse

      1. Well, there are all sorts of misleading techniques Tom. You can find them everywhere.

        This is another classic case of cherry-picking the evidence. Anthocyanins (blueberries, etc) are flavonoids that are absorbed in quite a unique manner amongst the polyphenols.
        It has been reported that milk affects bioavailability of anthocyanins, but this is also true for sucrose (Mulleder et al, 2002), carbohydrates (Nielsen et al, 2003, Walton et al, 2009), and other flavonoids such as quercetin (Walton et eal, 2006). Foods containing quercetin include: apples, peppers, red wine, berries (blueberries, bilberries, blackberries and others), tomatoes, cruciferous veggies, including broccoli, cabbage and sprouts, leafy green veggies, including spinach, kale, citrus fruits, onions. The more observant will note that blueberries themselves contain a flavonoid (quercetin) that also has the potential to modify the bioavailability of its other beneficial flavonoids. So, why selectively pick on milk? It is not the most objective means of of presenting the scientific evidence. In the absence of further evidence it is reasonable to assume milk per se is not necessarily the ‘culprit’. Other possibilities are sugar, carbohydrates and other flavonoids, all of which exist in a host of foods other than milk.
        If history is any guide, new research will be released which demonstrates the milk or milk fat (see below) improves the bioavailability of blueberry polyphenols.

        …..not all studies show a negative impact of milk addition to food on polyphenol absorption. Keogh et al.[48]monitored the concentration of catechin and epicatechin in the blood after consumption of chocolate polyphenols with and without milk proteins. Results showed that milk protein did not influence the average plasma polyphenol concentration after ingestion. …

        https://www.ncbi.nlm.nih.gov/pubmed/17995820

        ……a recent in vitro digestion study by Cebaci et al. reported that whole or skim milk decreased the total phenolic content of blueberries as well as an oatmeal and blueberry mix, but does not impact the potential bioavailability measured by a co-digestion assay.

        ….some studies have shown that the addition of dietary fat may also increase the bioaccessibility of polyphenols (Ortega, Reguant, Romero, Macia, & Motilva, 2009),

        …..Bioavailability of pelargonidin 3-O-glucoside was higher when strawberries were consumed with cream due to positive effect of the fat in cream on the absorption of strawberries in metabolism ( Mullen et al., 2008). …

        I believe Dr Greger would be well advised to exert the same caution as the experts in this matter. The following was written 6 years ? after the research study he is relying upon:

        ‘Prior to exerting their bioactivity, these compounds must be made bioavailable, and considerable differences may arise due to their matrix release, changes during digestion, uptake, metabolism, and biodistribution, even before considering dose‐ and host‐related factors. Though many insights have been gained on factors affecting secondary plant metabolite bioavailability, many gaps still exist in our knowledge. In this position paper, we highlight several major gaps in our understanding of phytochemical bioavailability, including effects of food processing, changes during digestion, involvement of cellular transporters in influx/efflux through the gastrointestinal epithelium, changes during colonic fermentation, and their phase I and phase II metabolism following absorption.’

        Mind the gap—deficits in our knowledge of aspects impacting the bioavailability of phytochemicals and their metabolites—a position paper focusing on carotenoids and polyphenols
        Torsten Bohn, et al. July 2015,

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5033009/

        In regards to the addition of milk to tea. The quoted Langley-Evans study conducted in 2009 involved only 9 subjects, and is inconsistent with the majority of other studies conducted. It is fair to say this is a controversial subject, with a great number of contradictory findings. Not that you would know this if you blindly accepted the outlier example Dr G has chosen. As we have previously discussed, it becomes a matter what one tests for, and how. For example, early in-vitro research demonstrated that the addition of milk to tea reduced the presence of beneficial polyphenols. This was the accepted wisdom for a decade until subsequent in-vivo research discovered that the minerals in milk initially increase the bioavailability of polyphenols when added to tea. However, this bioavailability is reversed during early digestion, but subsequently reversed again further into the digestive process. So, it rather depends on timing. In summary, the evidence now suggests there is a net increase in bioavailability of tea polyphenols with the addition of milk. Quoting the earlier incomplete and somewhat discredited evidence, and ignoring corrected subsequent evidence is unhelpful.

        Tea also improves FMD (a measure of blood pressure), and early research suggested this was adversely affected by the addition of milk. Subsequent research demonstrated that the addition of milk to tea actually enhanced FMD.

        The following is the gist of a discussion we had earlier on this subject on this forum:

        It is wrong to recommend against the addition of milk to tea (black or green) or coffee, particularly based upon the 2007 and 2013 research studies, Lorenz et al, and Nesteo et al. Both are in-vitro studies failed to include the consider the effect of the milk-bound polyphenols once digested in the human gut, which Lorenz subsequently conceded should have been done. This makes them completely worthless research studies. Subsequent research (Xie et al, Oct 2013, Moser et al, December 2014) indicates that when adding milk to tea (i.e., pre-consumption) milk minerals immediately increase tea flavanol bioaccessibility, milk protein (casein) reduce tea flavanol bioaccessibility – but the latter is completely reversed during human digestion (post consumption). Thus, the addition of milk increases (not decreases) the net bioavailability of tea polyphenols. Milk should be added to tea and coffee to obtain the maximum benefit of tea polyphenols.

        Reference 1: Moser et al, Dec 2014

        Milk protein, most notably S-CSN, significantly decreased (p < 0.05) bioaccessibility of flavan-3-ols relative to JK buffer controls (10 relative to 32%). Interestingly, the presence of milk minerals significantly increased (p < 0.05) flavan-3-ol bioaccessibility compared to that of controls (32 relative to 18%). These data combined with SDS-PAGE and fluorometric analyses suggest that both milk proteins and minerals may alter flavan-3-ol bioaccessibility, but normal GI digestion appears to minimize the impact of specific protein interactions.

        http://www.sciencedirect.com/science/article/pii/S0963996914006188

        Reference 2: Xie et al, Oct 2013

        To summarize, these data suggest that milk addition may increase catechin bioavailability by enhancing their transepithelial absorption and uptake from green tea extract.

        http://www.sciencedirect.com/science/article/pii/S0963996912003079

        ‘The results suggest that addition of milk may not obviate the ability of black tea to modulate the antioxidant status of subjects and that consumption of black tea with/without milk prevents oxidative damage in vivo’.

        https://www.ncbi.nlm.nih.gov/pubmed/16020939

        FMD

        Catechins in black tea appear to be improve FMD. However, flavan-3-ols include not only catechin, but also epicatechin gallate, epigallocatechin, epigallocatechin gallate, proanthocyanidins, theaflavins and thearubigins. The bioavailability of most if not all of these flavanols are improved with the addition of milk to black tea.

        The increase in FMD is only 3.5% with black tea. Similar increases in FMD follow consumption of a high-flavanol cocoa drink, oral ingestion of epicatechin, consumption of dark chocolate, and drinking of white and red wine. Subsequent to your quoted study the authors conceded it is probable the catechins in black tea that are bound to milk proteins (casein) subsequently break down in the gut to amino acids and peptides. At which point they may also have a positive effect on FMD. Unfortunately, this was not tested. Moreover:

        ‘We are also aware of the study by van het Hof et al.,6 who did not observe a difference in plasma catechin concentrations after consumption of black tea with or without milk’.

        https://academic.oup.com/eurheartj/article/28/10/1266/2887455

        The FMD study you refer to used skimmed milk, not whole milk. By your reasoning (your objection to milk proteins and minerals, see above) this would disqualify it as milk for the purposes of the experiment.

        In total, this makes their study next to worthless.

        Milk protein, most notably S-CSN, significantly decreased (p < 0.05) bioaccessibility of flavan-3-ols relative to JK buffer controls (10 relative to 32%). Interestingly, the presence of milk minerals significantly increased (p < 0.05) flavan-3-ol bioaccessibility compared to that of controls (32 relative to 18%). These data combined with SDS-PAGE and fluorometric analyses suggest that both milk proteins and minerals may alter flavan-3-ol bioaccessibility, but normal GI digestion appears to minimize the impact of specific protein interactions.

        This clearly demonstrates:

        1. By complexing, milk protein decreases the bioaccessability of flavan-3-ols in vitro

        2. However, milk minerals immediately increase flavanol bioaccesability

        3. Digestion overcomes the initial decrease of bioaccessability caused by milk proteins (casein).

        4. There is a net increase in bioaccessibility of tea flavanols with the addition of milk to tea.

        The good stuff in green tea are the flavanols – such as EGCG. They are bound by the addition of milk proteins. However this effect is reversed once processed by the gut. Indeed, cows milk may ultimately increase (not decrease) the bioavailability of these valuable flavanols:

        Milk protein, most notably S-CSN, significantly decreased (p < 0.05) bioaccessibility of flavan-3-ols relative to JK buffer controls (10 relative to 32%). Interestingly, the presence of milk minerals significantly increased (p < 0.05) flavan-3-ol bioaccessibility compared to that of controls (32 relative to 18%). These data combined with SDS-PAGE and fluorometric analyses suggest that both milk proteins and minerals may alter flavan-3-ol bioaccessibility, but normal GI digestion appears to minimize the impact of specific protein interactions.

        http://www.sciencedirect.com/science/article/pii/S0963996914006188

        Milk and Cocoa Drinks

        In a study on the effect of milk proteins on cocoa polyphenols, researcher's found that:

        ‘From a nutritional point of view, these data indicate that the β-Lg covalent modification by polyphenol alone do not support the hypothesis of a decrease in the bioavailability of polyphenols themselves (Scalbert & Williamson, 2000). This might also explain the maintenance of the antioxidant properties of cocoa polyphenols in cocoa-based beverages’.

        https://www.sciencedirect.com/science/article/pii/S0963996913003761

        Cocoa powder dissolved in milk as one of the most common ways of cocoa powder consumption seems to have a negative effect on the absorption of polyphenols; however, statistical analyses have shown that milk does not impair the bioavailability of polyphenols and thus their potential beneficial effect in chronic and degenerative disease prevention.

        https://www.ncbi.nlm.nih.gov/pubmed/18032884/

        In conclusion, milk powder did not influence the average concentration of polyphenols. While it slightly accelerated absorption, this is of no physiological significance.

        https://www.ncbi.nlm.nih.gov/pubmed/17995820

        ‘Cocoa powder dissolved in milk, as one of the most common ways of cocoa powder consumption, did not change the bioavailability of cocoa powder flavonoids in healthy humans [12]. Furthermore, lipid and protein rich meals did not affect the bioavailability of cocoa polyphenols. However the uptake of flavonols in humans could be increased significantly by concurrent consumption of carbohydrates [13].’

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2790109/

        1. Not too difficult to spot a dairy industry troll. Pete, your sole purpose for being on these boards seems to be to defend the dairy industry (at least based on the only comments of yours I’ve een). But when you’re asking people to ignore the well-established science all for a slew of cherry-picked nonsense you wish to present, you may want to choose a dumber audience.

            1. Waste of time debating him.
              —————————————————–
              Very true, because in researching a something, he follows a study by examining follow-up studies. Pete Granger has no peer on NF.o that I’ve seen, for doing in-depth research.

              Personally I don’t drink milk or eat yogurt because it disagrees with me, but I respect and admire Mr. Granger as a proficient researcher.

              1. Pete Granger has no peer on NF.o that I’ve seen, for doing in-depth research.
                ——————————————————————————————————-
                No offense, Tom.

  6. The combination of blueberries and yogurt brings the point of prebiotics ( blueberries) needed to support the action of probiotic. Commercial yogurts with berries is based on the old observation from Institute Pasteur Paris how yogurt improves immunology and vascular system. I was part of a team evaluating the effect of blueberries extracts impact on retinal vessels from patients with diabetes. I know well Auvergne, and yes, I recalled having seen old people with extremely good sight, and eating blueberries, having blueberries tea leaves etc. British pilots were eating blueberries to fly to Germany without lights during WWII. The compilation of these old observations and scientific observation helped me to continue the French family tradition to eat berries every day. I add berries in plain low fat or fat-free yogurt with avocado, to support the combination pre-probiotic, antioxidant and anthocyanins. We need all that to slow aging, and it works.

    1. Claude, if you haven’t actually watched the video, I suggest that you do. It states the opposite of what you’re advocating.

    2. Hey Claude, a fun historical tidbit for you: the whole ‘British pilots eat berries to improve their eyesight’ was a lie the British military propagated to hide the development of radar technology from the Germans

      1. Or perhaps the lie, lies with the person who said it was a lie.

        I know there have been questionable studies done that say the bilberries didn’t work, but they were tested on modern-diet people (if tested on people at all.) The actual WWII pilots were eating a 1930-40s wartime diet… a 70 year gap. It is possible the bilberries helped them but maybe any modern day subjects have something in their diet that moots the need for the bilberry benefit.

        Anyway the “eyesight lie” the British put out to hide the fact they had radar was that carrots were what were giving the pilots the advantage, not bilberries.

  7. What component of the milk is the culprit?
    Does raw milk dairy behave the same as pasteurized milk (I can safely eat the former but the latter gives me asthma)
    And is the effect the same if you eat blueberries and dairy (well aged cheese) in different meals?

    1. Chris,
      Thank you for your questions. I do not believe it is known to what extent the protein and the fat are the culprits. We do know from this study that something in the milk is inhibiting the phytonutrients in the blueberries. Since cheese retains the protein and the fat from milk my best guess is that it too would be a problem (although I do not think there have been any studies to determine this).You may be interested in the following studies regarding raw milk. https://nutritionfacts.org/questions/raw-milk-versus-pasteurized-milk/

  8. I remember the older video on this site that says Soy milk can prevent absorption of antioxidants too. Wonder if there are any updates on plant based milks and absorption of antioxidants?

    1. Fatima, that was specific to the antioxidants in tea, however this is an urgent question that I’m really hoping gets addressed ASAP as most WFPB dieters seem to pair berries with plant milk or plant protein and fat.

  9. I can hardly wait for the soy yogurt – blueberries study. I consume that combination about 1 or 2 times a week and love it. I also eat blueberries alone for a snack. I wonder if consuming each one (soy and blueberries) alone about an hour apart would be better? But blueberries sweeten unsweetened soy yogurt and I don’t want to use sugar. Please hurry with that study.

  10. Laughing.

    Nope, I am not going to even watch a negative blueberry video at all.

    I can already feel the “superhero placebo effect” which gets me to eat them slipping away, even though I don’t eat them in yogurt.

    Actually, this is timely for me. I started giving them to my dog and he ate them pretty well the first few days, but now leaves them on the bottom of the dish and eats around them.

    And I was pondering Coconut Yogurt or Almond Yogurt or Soy Yogurt, hoping he would eat them in that.

    But I am not kidding, I had been doing well eating even a whole cup of blueberries as long as I use the grape training wheel food combination, but my dog got sick and I started feeding them to him. Then, he stopped eating them and I stopped eating them.

    Will work on it later.

    It isn’t the blueberries fault.

    1. My dog eats berries and fruit mixed with oatmeal. He loves his fruits and veggies at age 16. You might try that. He also loves broccoli and cauliflower stems cut up which may also help your dog. Good luck.

  11. He has been looking well, since he came home, but, I think he looks less well today.

    I know it is a situation where I need a miracle, because I will have to heal the cancer, before his organs shut down.

    1. Deb, we have holistic vets here who use an herb called artemisinin in dogs with cancer with good results. They use curcumin and some mushrooms mixes also.
      Don’t know the dose of artemisinin, but you can probably find out.

  12. I think I am starting to see the effects of intermittent fasting this week.

    I am still eating the same food, pretty much.

    And I haven’t been exercising.

    I don’t weigh myself every day, but I weighed myself today and I think I lost 4 pounds this week.

    I was losing 2 pounds a week.

    That is double the results, just eating breakfast a few hours later.

    1. I think part of the difference suddenly is that I am doing the time restriction narrower, not on purpose.

      I spend the morning rushing around preparing things for my dog and it pushed my start eating time from noon until two.

  13. I make my berry smoothies with fats from flax and/or hemp, typically… thoughts on plant fats with berries?

    And what about berries and soy milk or even just whole soy? I ask since soy milk also interferes with tea.

  14. Yogurt is not that good for you anyhow. Sure it contains ‘probiotics’ but most of them are destroyed in the stomach because yogurt also contains protein which stimulates more acid production in the stomach to digest the protein. And SURPRISE, yogurt itself DOES NOT NATURALLY CONTAIN acidophilus. That is added after the milk is cultured with Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus which are the two bacteria that actually make all yogurt. Any additional bacteria are added later and are not part of the yogurt culturing process. If a person wants to culture their own probiotic beverage without dairy then I would consider “water kefir”. Info is available online. All you will need to order is some water kefir grains. Cultured vegetables such as sauerkraut, pickles, and kim-chi do also supply probiotics to the diet IF they are preservative free, require refrigeration, and preferably do not list vinegar on the ingredient list (as this means all of the vinegar in the finished product came from the culture process.

    1. Yes yogurt is a pointless little thing isn’t it… at best.
      Don’t forget that the best probiotics are found on the surface of plant foods! And washing does not get rid of them.

    2. I want to add that I really enjoy eating blueberries in the ‘Summertime Oatmeal’ recipe found in How Not to Die Cookbook. It is my favorite way to eat oatmeal now.

  15. Didn’t notice if this was covered in the comments yet but I put cashew yogurt in my smoothie along with blueberries (and a million other plant based things…). I’m assuming (hoping ?) that the effect discussed in the video is restricted to dairy and there isn’t some similar effect that results from fermented nut fats, though I guess the upcoming video on soy yogurt will be applicable.

    1. I’m thinkIng if it’s shown that soy does not have any blocking effects then it would be applicable to all other high protein/fat plant foods. But if it is shown to have a blocking effect, it won’t mean all other things do as well. So hopefully in that or an upcoming video all this will be addressed.

  16. I recall a few years ago a researcher presented the findings of feeding dark chocolate to rats which was beneficial. He said that using milk chocolate was not beneficial however. Looks like milk’s countering of beneficial effects isn’t confined to blueberries.

  17. Hey, I love your work Mr Greger will you be making more videos on sugar soon? as the focus is on sugar now and there’s a lot of research coming out.

    There is someone who is trying to prove to me that sugar is a bigger cause to heart disease than saturated fat or cholesterol due to this study:

    http://www.clinsci.org/content/early/2017/09/15/CS20171208

    Apparently it’s peer reviewed and my referenced metabolic ward experiment studies have no weight because “studies of a certain type relating to diets over long periods struggle to provide factual evidence”.

    I’d love some help on this.

    Thank you sir.

    1. This is a wonderfulillustration of the twisted thinking that staurated fat and keto advocates emply to try to justufy their dietary choices.

      The study is about non-alcholic fatty liver disease not cardiovascular disease. It simply ‘provides new evidence that liver fat accumulation leads to a differential partitioning of hepatic TAG into large and small VLDL subclasses, in response to high and low intakes of sugars.’ This hardly demonstrates that sugar is a bigger risk factor for cardiovascular disease than eg saturated fat.

      I doubt if your friend is open to considering all the relevant evidence or to rational discussion of what it means. All such people do, in my experience, is quickly dismiss all evidence they don’t like with some glib but meaningless phrase like the one you have just quoted, and then insist on discussing an obscure out of context study like this one which they inexplicably seem to believe proves their case based on a peculiar 2+2=4 logic which only they find convincing.

      However, if he claims to be interested in the mechanisms by which certain nutrients affect cardiovascular disease risk, you could try mentioning these to him which show the damaging effects of high saturated fatty acid (SFA) diets on the endothelium

      ‘Conclusion— High SFA caused deterioration in FMD compared with high PUFA, MUFA, or CARB diets. Inflammatory responses may also be increased on this diet.’
      http://atvb.ahajournals.org/content/25/6/1274.full

      ‘Consumption of Saturated Fat Impairs the Anti-Inflammatory Properties of High-Density Lipoproteins and Endothelial Function’
      https://www.sciencedirect.com/science/article/pii/S0735109706013386

      ‘These results indicate that the capacity of the endothelium to release t-PA is lower in middle-aged and older adults who habitually consume a diet high in saturated fat. In conclusion, endothelial fibrinolytic dysfunction may underlie the increased atherothrombotic disease risk with a diet high in saturated fat.’
      https://www.ajconline.org/article/S0002-9149(14)01311-3/abstract

      But damaging the endothelium isn’t the only way, SFA consumption increases risk – research group from the Montreal Heart Institute in Canada, led by Dr. Nicolas Bousette, evaluated the impact of palmitate and oleate on cellular fatty acid absorption, triglyceride synthesis, intracellular lipid distribution, ER stress, and cell death in primary cardiomyocytes. This is the first time that such phenomena were observed in cells directly derived from the heart, validating a critical role for saturated fatty acids in the development of heart diseases.
      https://medicalxpress.com/news/2015-04-saturated-fatty-acids-heart.html
      ‘Saturated fatty acids induce endoplasmic reticulum stress and apoptosis independently of ceramide in liver cells.’
      https://www.degruyter.com/view/j/ersc.2015.2.issue-1/ersc-2015-0004/ersc-2015-0004.xml

        1. Thank you so much Nancy. I just wish I would proof-read them before I post them but I always seem to be in a rush to be somewhere else

          2+2=5 logic!

  18. I have a coupe of questions. What is considered processed food? Is there anything not processed or tampered with anymore? Including vegetables. And is there anyway we can have sustainable food for everyone on this earth?

      1. Hi Andy, technically even grinding up an herb or seed is “processing” it, but when people refer to processed foods which we should avoid or drastically limit, they’re typically referring to commercial foods made from ingredients stripped of nutrition such as bleached flour, and with a lot of unhealthy addditives.

        Yes it’s definitely possible to sustainably feed the world through plant based eating and organic is the most sustainable farming method for various reasons despite the grotesque slew of propaganda put out there by Monsanto and other GMO corporations.
        I have the numbers saved but I’m on my phone right now, so I can only say that it’s been estimated that if the U.S alone ended animal agriculture, it could feed millions of people. For some common sense perspective, it takes about 16 lbs of grain to produce 1lb of “beef.” And on a global scale, animal agriculture is the number 1 cause for deforestation (palm oil is another huge one). You’ll likely see desperate arguments about soy and land use, but what will be missing from those arguments is the fact that 90 or more than 90% (tired and going on memory) of the worlds soy is grown for “livestock.”
        I highly suggest the documentary Cowspiracy if you haven’t seen it already, there’s lots of animal agriculture industry backlash as there always is when light is being shed on a multibillion dollar industry but the numbers are out there and it really just comes down to common sense.

    1. “And is there anyway we can have sustainable food for everyone on this earth?”

      In my opinion, to meet your requirement of sustainable and healthy for everyone we must be willing to accept frozen, dried, even fermented along with fresh… There are untold amounts of good food that is thrown away because of over-preparation or just no way to keep it fresh until consumption.

      We can help this somewhat by growing vertically and indoors, but even that probably results in an overabundance of fresh due to close proximity of harvest. (You can stagger harvest when grown indoors by staggering planting, but even then it is expected to over-produce as future need is a moving target)

      To keep things in balance we have to accept preservation as somewhat healthy. And since we are all different in our make-up, there just is no one true healthy diet.

    2. I’ve heard either Dr. Greger or someone with Forks Over Knives say that processed food is that from which something is removed and/or to which something has been added.

      1. According to that definition, turmeric powder, which Dr. Greger recommends, is a processed food. So is amla powder. So are other south Asian spices like cloves, cumin, cardamon.

        1. I thought that amla powder was simply ground whole dried Indian Gooseberries, and turmeric powder is simply whole ground turmeric root. Ditto for black pepper etc. Ideally, in high quality spices nothing is added and nothing is taken away. Read the nutrition label to see if anything has been added before buying though.

  19. Hello Dr. Greger,

    A lot of the smoothies I love either use almond milk or soy milk. Do these negate the benefits of berries? I remember that in your video on soy milk put to the test vs. tea, it turned out that soy milk canceled out the benefits of tea just as much as milk did, because its proteins appear to bind up the polyphenols.

    Does soy milk or almond milk block the benefits of berries as well? How does one propose this to be put to the test?

  20. Do we know for sure, it’s the protein (animal or plant) blocking the benefits or could it just be the calcium in dairy or fortified milks inhibiting the effects just as calcium does with iron etc.?

  21. Hi, Syd! Thanks for your question. Antioxidant bioavailability and mineral bioavailability are very different, so it is unlikely that calcium would inhibit effects of blueberries the same way it competes for absorption with iron. As Dr. G. states in the video, it may not be just the protein, since the effect is greater with whole fat milk than with skim milk, but the effect may also be due to the fat. Skim milk tends to be more concentrated in protein and calcium than whole milk, because removing the fat means that more remains of the other components in the same amount of milk, so these results seem to support my assertion that it is unlikely that the calcium is responsible for this effect. As Dr. G. is so fond of saying, however, “We don’t know, until we put it to the test!” I hope that helps!

  22. I have just watched the video of the Benefits of Blueberries for Blood Pressure May Be Blocked by Yogurt I have blueberries with Soya yogurt and wonder if the reduced benefits are the same with that as it is with milk yogurt.

    Many thanks

  23. Soy yogurt probably does not block the benefits of blueberries as long as it does not contain any dairy products. Keep in mind that soy yogurt is not a whole food and is processed, which is not good.

    Dr. Ben

  24. You mentioned anthocyanins, so I searched for the content of anthocyanins in raisins compared to other foods. Several reliable references cited raisin’s benefial health effects and high antioxidant content: https://www.ncbi.nlm.nih.gov/pubmed/20851304/ Polyphenol content and health benefits of raisins.
    https://www.ncbi.nlm.nih.gov/pubmed/23789931 Raisin consumption by humans: effects on glycemia and insulinemia and cardiovascular risk factors.

    However, I had a hard time tracking down anthocyanins specifically until I found a seemingly reliable reference by no less than the Raisin Advisory Board which stated: http://ispub.com/IJNW/10/1/6985/ Overview Of Antioxidants: Emphasis On Raisins
    “Blueberries, which are rich in antioxidants, have similar amounts of polyphenols to raisins (Hall C, personal communication, 2006). The average phenolic content of blueberries was 548.55 ± 89.317 mg/100 g compared to 514.39 ± 32.921 mg/100 g for raisins. The range for phenols in raisins was between 477.3 ± 103.2 mg/100g for Thompson, up to 799.4 ± 44.1 mg/100g for golden raisins. Sub-groups of these phenols differed between blueberries and raisins. Anthocyanins are almost non existent in raisins (< 2 mg/100g), whereas they are high in blueberries 89.22 ± mg/100g."
    It doesn't appear raisins are a reliable source of antocyanins, although they do have several other positive phenols like other purple fruits.

  25. I was really surprised NOT to find any reference to “Kefir” on my SEARCH of the nutritionfacts.org site. If ever any potential food source needed further scientific verification of all the claims for amazing benefits of consumption, “Kefir” tops the list. Not finding anything on nutritionfacts.org, I went to the internet.
    Wow, all the claims and tutorials available online were overwhelming. Purchase of various forms of “Kefir” are available everywhere online and even found some to purchase in my local supermarket.
    It was a 1 quart bottle of the “Lifeway” brand of “KEFIR cultured lowfat milk smoothie”. It claimed to contain 12 live, active probiotic cultures and containing “1 gram of added sugar per ounce”, flavored with “Pomegranate and other natural flavors” w/ 4 servings per quart (32 fluid ounce) container.
    I found the following link to a YouTube video on how to make Kefir and a listing of the purported benefits: https://www.youtube.com/watch?v=SH7L_ZfVU3A
    I found the following link to 135 scientific studies done between 1949 and 2017 on various aspects of Kefir:
    https://link.springer.com/article/10.1007/s12602-014-9168-0
    HELP! John R.

  26. Hi, John Randall. You are the second person today to ask about kefir. You are correct in stating that the topic has yet to be covered here on NF. I agree that it should be, and I have passed on the request. Dr. G. is very busy writing a new book right now, but he will return to making new videos when it is completed. There are many reasons not to recommend dairy products. You can find links to videos on dairy here:
    https://nutritionfacts.org/topics/dairy/
    I am curious, however, to learn more about water or other non-dairy kefir. Thanks for your request. Please stay tuned (patiently) for an answer!

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