The Right Kind of Chocolate Is Heart Healthy

Dark Chocolate, Cocoa Help Keep Blood Flowing

Research points to the health benefits of dark chocolate including heart health and an enhanced blood flow.

But before you run out to the local chocolate shop, here's a word of caution: not all chocolate is heart healthy. White chocolate, which a Harvard researcher points out is "not really chocolate at all," and milk chocolate may expand the hips rather than help blood flow. And none of the instant cocoa mixes in the local grocery store contain the flavonoids that improve blood vessel function.

Yet, even with those cautions, researchers at the Nineteenth Annual Scientific Meeting of the American Society of Hypertension are enthusiastic about the chocolate potential. "It seems like the general public has known more about the benefits of chocolate than the scientific community has," says Naomi Fisher, MD, associate professor of medicine at Harvard Medical School in Boston. While noting that humans have been drinking cocoa for more than 2,000 years, Fisher notes that European researchers are more enthusiastic about the health benefits of dark chocolate than researchers in the U.S.

Flavonoids May Be Reason:

Fisher says that the flavonoids in cocoa may help prevent stiffening of blood vessels, a common side effect of aging.

In one study, 27 healthy adults were given a special cocoa drink containing high levels of flavonoids. While the cocoa had a modest effect in younger adults, "it was associated with a significant benefit in adults over age 50," she says.

She says the most likely explanation for the benefit is that the cocoa controls activation of an enzyme called nitric oxide synthase, which helps keep blood vessels open and blood flowing.

In another chocolate study, Charalambos Vlachopoulos, MD, of Athens Medical School, reports that eating a candy bar with 100 grams of dark chocolate also makes blood vessels work better. Vlachopoulos asked 17 healthy volunteers to eat a candy bar made by the Nestle Company and then used ultrasound to measure the blood flow in their arteries. To rule out any possible benefit from the act of chewing, the volunteers were then asked to "simulate chewing" and had blood flow measured again.

He says that blood flow measurements taken after the volunteers ate chocolate were much better than after the simulated chewing. Vlachopoulos thinks that flavonoids explain the difference. He says red wine has a high flavonoid concentration that may explain its heart benefit but "dark chocolate has even more flavonoids," suggesting that dark chocolate may provide a health benefit as good as, or better than red wine.