Chocolate—in Moderation—May Lower Blood Pressure
Put down that box of bon-bons, and back away slowly. Despite the promising results of a recent study linking dark chocolate with lower blood pressure, it's too soon to recommend that everyone start eating the stuff—especially since Americans are used to consuming large quantities.
Yes, there is mounting evidence that some of the chemicals called flavanols concentrated in cocoa products may help your heart. And the most recent research, published in the Journal of the American Medical Association, certainly adds support. The study, by researchers at the University Hospital of Cologne in Germany, randomly assigned 44 older adults with early, untreated hypertension or warning signs of it to eat a small amount of dark chocolate or an equal amount of white chocolate—which, lacking cocoa, has no flavanols—every day for 18 weeks.
The white-chocolate group experienced no changes, but the dark-chocolate eaters saw their average systolic blood pressure (the top number in a blood pressure reading) drop by almost 3 points, and their diastolic pressure (the bottom number) drop by almost 2 points. That may not sound like much, but because hypertension is so common, those kinds of changes across a population are estimated to cut the risk of stroke mortality by 8 percent and of all-cause mortality by 4 percent. (Other, less rigorous studies have found even greater effects.)
The change in the dark-chocolate group, says study author Dirk Taubert, a pharmacologist, is about the same as the change seen by people adhering to the anti-hypertension DASH diet, which restricts fat and cholesterol (and is therefore considerably more difficult to follow than advice to eat chocolate).
But the study focused on such a small amount of chocolate for a reason. "If you eat too much of it, you gain weight, which can produce hypertension," says Taubert. So anyone looking for an excuse to eat a Hershey's Special Darkbar would have to make that bar last almost a week to get the benefits shown in this study without also risking the unfavorable effects of fat and sugar. "The low and regular dose is important," says Taubert. So is the darkness: The sweeter and milkier your chocolate is, the less cocoa it has—and the fewer beneficial chemicals.
It's also unclear from this small study whether the same benefits will show up in different populations, like people with established hypertension or younger folks. And no one really understands precisely which of these flavanols is responsible for the benefits. So researchers are focusing on isolating that specific component and figuring out how to give it in a consistent form, then testing its effects in different populations, says Alice Lichtenstein, director of the cardiovascular nutrition lab at the Friedman School of Nutrition at Tufts University.
So you won't find the government recommending you eat chocolate anytime soon. But in the meantime, if you are already a chocolate fiend and don't have a weight problem, you can continue to enjoy it in moderation, says Lichtenstein. Assuming you've got the willpower to do so.