GLASGOW, Scotland (Reuters) - Good news for chocoholics. The treat favored by millions may also be good for you, US researchers said Monday.

Chocolate contains compounds called flavonoids that can help maintain a healthy heart and good circulation and reduce blood clotting--which can lead to heart attacks and stroke.

``More and more, we are finding evidence that consumption of chocolate that is rich in flavonoids can have positive cardiovascular effects,'' Carl Keen, a nutritionist at the University of California, Davis, told a science conference.

``We not only have observed an increase in antioxidant capacity after chocolate consumption, but also modulation of certain compounds which affect blood vessels.''

Antioxidants are substances that help reduce the effects of cell-damaging free radicals in the body. Fruits, vegetables, nuts and whole grains are high in antioxidant vitamins such as C and E.

Keen presented research on the effects of chocolate on blood clotting to the British Association for the Advancement of Science conference here. The study was funded by the confectionery maker Mars Inc.

NOT ALL CHOCOLATE CREATED EQUAL

Flavonoids in chocolate are derived from cocoa, which is rich in the compounds. Some research has shown that a small bar of dark chocolate contains as many flavonoids as six apples, 4.5 cups of tea, 28 glasses of white wine and two glasses of red wine.

But Dr. Harold Schmitz said there are variations in the levels of flavonoids in chocolate and cocoa products depending on the production process, during which many flavonoids can be destroyed.

``All chocolates are not created equal in regards to flavonoid content,'' Schmitz, a scientist with Mars, told a news conference.

Flavonoids are thought to reduce the risk of cardiovascular disease, the leading cause of death in many industrialized countries, by reducing platelet aggregation--when blood platelets combine into a sticky mass and form clots.

But the British Heart Foundation said that although chocolate contains flavonoids, it also has high levels of saturated fats and sugar.

``Fruits and vegetables contain much higher levels of flavonoids, plus many other beneficial nutrients without the fat content,'' the foundation said.

``So the message is, enjoy a little chocolate in moderation, but ensure you eat five portions of fruit and vegetables daily to get all the flavonoids you need without the added fat,'' it advised.

Keen and his colleagues measured the impact of chocolate on platelets in the blood in 25 volunteers.

The researchers collected blood samples from volunteers who ate 25 grams (0.9 ounces) of chocolate with a high flavonoid content and other volunteers who ate bread. They took blood samples from both groups 2 and 6 hours after they ate the chocolate or bread to measure their platelet activation.

Volunteers who consumed the chocolate had lower levels of platelet activity, which would reduce the probability of having a blood clot. The scientists found no change in the group that ate the bread.

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