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If you compare the artery function of those who don’t eat meat to those who do, the healthy ability of arteries to dilate and let more blood flow is significantly better among those eating vegetarian––and not just by a little; we’re talking four times better. Well duh, vegetarians tend to be younger, smoke less, be slimmer, and have lower rates of diabetes, high cholesterol, high blood pressure, and heart disease. But, the researchers controlled for all that. They only let healthy nonsmokers into the study, and recruited a group of meat-eaters who were about just as slim, on average, about the same blood pressures, even practically the same cholesterol––a really healthy cohort on omnivores. Yet they still got their arteries handed to them by the vegetarians, and the longer someone was meat-free, the better. The degree of superior artery function correlated with the number of years eating meat-free. Instead of their artery function worsening over time as they aged, it got better the longer they ate that way. This suggests that vegetarian diets, by themselves, have a direct beneficial effect on artery function, and may help to account for the lower incidence of atherosclerosis and cardiovascular mortality.

Since researchers were able to control for other known risk factors, they figured it must be the food. But what aspect of the food? Is it simply the lack of the deleterious effect of meat? Or could it also be because the vegetarians may simply be eating more whole healthy plant foods––for example, up to a serving a day more vegetables?

When researchers compared two crappy meals, Sausage and Egg McMuffins to Frosted Flakes, and found the fatty meal impaired artery function within hours, but the sugary meal didn’t, they blamed the fat. But it may just be the animal fat, since high-fat whole plant foods like nuts don’t have the same effect. In fact, if you look at a systematic review of all the randomized controlled trials on the effect of nut consumption on artery function, you find that nuts actually make things better over time.

Enough to counter the artery-crippling effects of a salami sandwich? Let’s find out. And the answer is yes for walnuts, but no for almonds. Just like there are some fruits that are better than others––like blueberries over bananas––there are some nuts that are better than others. And walnuts appear to be the blueberries of nuts.

What about the blueberry of berries? Blueberries themselves. A randomized, controlled, crossover trial of cooked blueberries, raw blueberries, or no blueberries at all. If you feed people buns made out of white flour, eggs, butter, and salt, and fill them full of mostly sugar and eggs, you get a gradual drop in artery function over the next six hours. But add the equivalent of a cup of wild blueberries to that same bun, and instead, you get a big boost in artery function––almost as if you had just mixed the blueberries with water.

About the same amount of strawberries failed to rescue artery function from the likes of two cheese blintzes, with whipped cream, a sugary syrup, egg, and bacon. But that is quite the heavy load to bear.

What about açai berries versus a meal with a similar amount of fat? One and a half-frozen smoothie packs with half a small banana in water were able to significantly rehabilitate arterial function, compared to a control smoothie with the same banana and water colored to look like the açai one––though obviously it would have tasted differently. This group of researchers went all out and performed a double-blind randomized controlled trial with raspberries, measuring artery function after two hours and then 24 hours after drinking about ¾ of a cup of frozen red raspberries (about 187g) blended with water (or about a cup and a half), versus a placebo drink meant to match both color and taste. The fake berry drink had no effect on artery function, but the other two did.

Note the ¾ cup dose seemed to work just as well as the cup and a half dose, which is what you see with blueberries: the benefits plateau after about a cup.

The bottom line is that consumption of dietarily achievable amounts of red raspberries acutely improves artery function for up to 24 hours. You say, “Yeah, but by the end of the day, you’re only up like one percent.” Ah, but at a population level, each one percent increase is associated with a 12 percent reduction in risk of a cardiovascular event like a heart attack or stroke. All from just having a berry smoothie.

What about berry juice? Five different concentrations of cranberry juice were used, along with a placebo control evidently indistinguishable in color and taste. The 25 percent cranberry juice drink gave a little bump at two hours; the 50 percent juice was still working eight hours later. The 75 percent juice, the one that was nearly pure juice, and the ultra-concentrated juice also improved artery function within hours of consumption. But this, like that last raspberry study, just involved straight berries without some artery-crushing meal.

Would berry juice be able to stop artery dysfunction caused by a high-fat meal this unhealthy, squeezing down artery function within hours? Researchers created a cocktail of grapes, lingonberry, blueberry, strawberry, and black Aronia berry, and were able to turn this, into this. No significant change after the high-fat meal. Of course, if you had just drunk those berries alone, you’d probably get an improvement, but it’s better than nothing.

Well, what about something a little less exotic than black Aronia berries? What about OJ? Participants were provided a high-fat meal of ham and cheese croissants, along with a cup of either water, orange juice, green tea, or red wine. The arteries didn’t much like the croissants, and OJ was useless, as was a cup of green tea and red wine. So, it’s probably best to not eat ham and cheese croissants in the first place.

In fact, drinking orange juice with a fatty meal could actually make things worse. If you give people bacon and cheese muffins with or without orange juice, the OJ can lead to a prolongation of elevated fat in the blood, as your body preferentially burns for energy all the rapidly-absorbed free sugars in the juice––meaning sugars not encased in cells walls like in whole fruit.

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