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Vol. LVII, No. 21
October 21, 2005

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Researchers Ask, 'Is Chocolate Good for You?'

Chocoholics everywhere have reveled in recent reports that dark chocolate might actually be good for their health. Sound like the beginning of a new health craze? Well, the jury is still out on the long-term health benefits of consuming dark chocolate, but there are some promising findings about this sweet indulgence.

What is it about dark chocolate that is potentially good for you? Believe it or not, chocolate is a complex substance containing a number of valuable compounds including sterols, fiber, minerals and flavonoids. The compound currently of most interest is flavonoids, antioxidants found in a number of foods such as red wine, green tea, apples, and yes, chocolate. What do these antioxidants do? Preliminary evidence suggests that they can ward off vascular disease (vascular disease is a precursor to heart attacks, strokes, diabetes, dementia and hypertension), in part, by helping the body make or preserve a chemical called nitric oxide, which improves blood flow. Cocoa is a particularly rich source of flavonoids, and dark chocolate typically contains a higher percentage of cocoa than other types of chocolate. Basically, the darker the chocolate, and the more bitter, usually the better.

Drs. Michael Quon and Rajaram Karne, researchers at the National Center for Complementary and Alternative Medicine, are excited by the possible benefits of chocolate. Quon, who is chief of NCCAM's intramural diabetes unit, explains, "Chocolate is a tasty food that also has the potential for improving metabolic and cardiovascular physiology. It's what we call a functional food — a food that has potential health benefits." These researchers are interested in the benefits of a particular flavonoid found in cocoa called epicatechin. They believe this is the active ingredient in chocolate that is beneficial for cardiovascular health.

To test this hypothesis, NCCAM is currently recruiting volunteers for a clinical trial (see advertisement on p. 15) that will examine the effects of dark chocolate on blood pressure and insulin sensitivity in patients with hypertension. They want to know if the epicatechin in chocolate can help decrease insulin resistance in hypertensive patients, which would in turn increase the production of nitric oxide. Nitric oxide helps prevent the constriction of the arteries and capillaries in the body, increasing blood flow and improving vascular function. The outcome of this study will begin to answer questions about the benefits of consuming dark chocolate. Because cardiovascular and metabolic diseases are intricately linked, epicatechin may prove to be a valuable preventive for a host of conditions including diabetes, obesity, hypertension and cardiovascular disease.

Before you rush out to buy your favorite candy bar, however, there are a few things you should know. Most chocolate is not flavonoid-rich. In fact, the process used to make chocolate often destroys much of its antioxidant properties. Consumers usually have no way of knowing whether a chocolate product is flavonoid-rich. Quon cautions, "It is premature to say that people should be eating chocolate for health benefits — most studies have only shown short-term benefits." There is potential, however, and that is what NCCAM plans to examine more closely in its dark chocolate clinical trial. So chocoholics don't despair — there is still hope.