Cocoa compounds enhance a region of the brain that is used for memory. The dentate gyrus, a part of the hippocampus whose function declines in correlation to aging is therefore considered to be a possible source of age-related memory decline. A number of healthy men and women ages 50-69, were randomly assigned to receive either a high-flavanol diet or a low-flavanol diet for three months and underwent brain imaging and memory tests before and after the study. Researchers observed significant improvements in the function of the dentate gyrus in those who consumed the high-cocoa-flavanol drink as compared to the low-flavanol diet. It was found that a high-flavanol supplementation enhanced function, establishing that dysfunction is a major factor in age-related cognitive decline.