Cocoa compound increases brain blood flow

February 26, 2007 at 12:17 pm

From San Francisco, at a meeting of the American Association for the Advancement of Science

Cocoa that retains compounds usually removed to soften the product’s flavor can significantly improve blood flow to the brain, say researchers. The finding could eventually lead to treatments for a variety of ills, including strokes and dementia.

Since the early 1990s, Norman Hollenberg of Harvard Medical School in Boston and his colleagues have been studying the Kuna, native people that live on islands off the Caribbean coast of Panama. Unlike typical Americans, the Kuna people have a low incidence of high blood pressure and their blood pressure doesn’t usually rise with age. These factors lower their risk of diseases associated with high blood pressure, such as heart attacks, diabetes, strokes, and some types of dementia.

Hollenberg’s team noticed that Kuna who moved away from the islands onto the Panamanian mainland lost this protection from high blood pressure. When the researchers searched for factors that differed between the island and mainland populations, they found that island Kuna drink several cups of cocoa during the day but that mainlanders typically don’t.

Unlike the cocoa sold in most U.S. stores, Kuna cocoa is only minimally processed, leaving in large quantities of compounds called flavonoids. Since these compounds have a bitter taste, they’re often removed from mass-produced cocoa.

In a recent study in the United States, Hollenberg and his colleagues gave cups of flavonoid-rich cocoa to a group of people age 50 or older. Other people received cocoa without flavonoids.

Tests showed that people who drank the flavonoid-rich beverage had about a 10 to 15 percent increase in blood flow to the brain. People who drank cocoa without flavonoids had no significant blood-flow increase.

Hollenberg notes that some U.S. chocolate manufacturers are starting to make bars and beverages that contain large quantities of cocoa flavonoids, which could provide some health benefits to consumers. In the future, he adds, researchers may develop highly potent pill versions of cocoa flavonoids to fight high blood pressure and associated diseases.