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WASHINGTON Dark chocolate is known to help prevent heart disease, but eating too much of it may be not so good for your body weight. But never fear! Scientists are looking for a way to concentrate dark chocolates helpful ingredients in supplemental pills.

Cocoa contains chemicals called flavanols that may help reduce the risk of strokes and heart attacks by lowering blood pressure and bad cholesterol levels and improving the bodys use of insulin.

Washington chocolatier Steve Koumanelis said that is one reason dark chocolate is increasingly popular among his customers.

A lot of people are gravitating towards dark chocolate because they just decide they love it, and they also have been reading all about the health benefits of dark chocolate, said Koumanelis.

But those benefits have not been confirmed by studies involving large numbers of people. Also, during the manufacture of chocolate, many flavanoids are destroyed, while sugar and saturated fats are added to contribute to flavor.

Scientists now want to learn the benefits of flavanols in their unadulterated form. They plan a four-year study of 18,000 adults, who will take capsules of pure cocoa flavanols, in what is being called the largest test of its kind.