Flavanols are the chemicals in chocolate, as well as in wine and teas, that are responsible for many of the nutritional bonuses that it offers, including improved circulation and general heart health. These antioxidants have also been shown to increase the flow of blood to the brain in research presented to the American Association for the Advancement of Science. Increased blood flow to the brain has been associated with improved cognitive performance in healthy people, as it carries more oxygen to the brain than when high-flavanol cocoa is not eaten. Since one of the symptoms of dementia is a decrease in the flow of blood to the brain, scientists think that cocoa that is high in flavanols could be used to decrease the impact of the disease.
Unfortunately, many commercial chocolates are low in flavanols, so you probably won't experience any of the benefits demonstrated by this study if you eat an extra Snickers bar. The reason for this is that flavanols add a bitter taste to chocolate, which many manufacturers - especially of sweet milk chocolates - prefer to eliminate from their final products. An exception to this is CocoaVia, which is specifically infused with flavanols. CocoaVia aside, the highest concentration of flavanols is found in cocoa, meaning that dark chocolate is a better choice for your health than milk chocolate, but a cup of hot cocoa is going to be your best bet.
A team of scientists from the U.S. and Germany
have pinned down one of the chemicals responsible for chocolate's positive effects on the heart. While it's been known
for some time that a group of chemicals called flavanols--found in tea, wine and cocoa--are good for the vascular
system, these recent findings identify a specific chemical, epicatechin, as linked to improved circulation and heart
health. Scientists from University of California, Davis, Harvard Medical School and the Heinrich-Heine University of
Duesseldorf, Germany published the results of their study in the January 17 issue of the 
