Apparently good news for chocoholics - it may be good for you, U.S. researchers said on Monday at the British Association for the Advancement of Science in Glasgow. Chocolate contains compounds called flavonoids that can help maintain a healthy heart and good circulation and reduce blood clotting - which can cause heart attacks and strokes, Reuters reports. "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 damage of cancer-causing charged particles in the body. Fruits, vegetables, nuts and whole grains are high in antioxidant vitamins such as C and E. Flavonoids in chocolate are derived from cocoa, which is rich in the compounds. 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. But Dr Harold Schmitz said there are variations in the levels of flavonoids in chocolate and cocoa products depending on the production process, in which many flavonoids are destroyed. "All chocolates are not created equal in regards to flavonoid content," Schmitz, a scientist with confectionery maker Mars Inc, told a news conference. Flavonoids are thought to reduce the risk of cardiovascular disease by reducing platelet aggregation - when blood platelets combine into a sticky mass and form clots. A spokesman for the British Heart Foundation warned 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 spokesman continued. 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 two and six hours after they ate the chocolate and 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.