The Right Kind of Chocolate Is Heart Healthy
Dark Chocolate, Cocoa Help Keep Blood Flowing
By Peggy Peck
Web MD Medical News Reviewed By Michael Smith, MD
on Thursday, May 20, 2004
May 20, 2004 (New York) -- Willie Wonka had the right idea. Chocolate -- at least dark chocolate -- is good for the heart and can improve blood flow.
But before you run out to the local Godiva 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 tells Web MD
that European researchers are
more enthusiastic about 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 tells Web MD that he, too, 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 it may provide a benefit as good as or
better than red wine.
Long-Term Effects?
Daniel T. Lackland, Dr PH, professor of medicine at the Medical University of South Carolina in Charleston, tells Web MD that it's intriguing to consider chocolate as a heart-healthy food, but he
points out that both studies demonstrate only an immediate benefit. "We don't know if there are long-term benefits or if chocolate could even prevent heart disease."
Moreover, Lackland says that many "chocoholics" are at risk for obesity, which could cancel out any benefit that the candy might provide.
Nonetheless, Lackland says that "other nutraceuticals like olive oil and omega-3-fatty acids have demonstrated long-term benefits. So it is possible that chocolate may also prove to be useful."
