A preliminary medical study has indicated that an ingredient in chocolate may improve the circulation of blood in the brain and heart.

Scientists at the American Association for the Advancement of Science discussed the findings Sunday at a convention in San Francisco, California.

They said flavinols, an anti-oxidant found in cocoa beans, can increase blood flow to the brain. But researchers caution us not to start eating chocolate for its health benefits.

They say the flavinols are removed from most chocolate because they have a bitter taste. Scientists say larger-scale testing is needed to back up the early research.

They also say eating high-calorie foods - like chocolate - can lead to health problems.

Some information for this report was provided by AP and Reuters.