 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 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 happen to have other healthy habits, and that's the real reason they did better. I mean, after all, you're probably more likely to sprinkle blueberries on an oatmeal than 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 benefits 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's 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 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. And now, 131 is still too high. I mean, 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's 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. What? Wait, what? I just showed you two studies where there was this gorgeous effect. I mean, 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, and they just mixed the blueberry powder with water. However, the blueberries in the non-significant effect studies were prepared with yogurt or 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-fighted nutrients 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 the 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 antioxidant 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 fighting nutrients, but not others. So did it really matter that much, though? Here's the spice in the bloodstream after blueberries with water, and here's how much is absorbed with milk. Okay, so less, but check out what happened 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 maybe be less of a bump, right? You can say that again, not just less, but less than when 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, and this suggests that there may be some nutrient blocking involvement from the dairy fat as well.