A natural compound found in cocoa, blueberries, tea and grapes enhances memory in mice, especially when combined with exercise, according to newly published research.

The compound, called epicatechin, is one of a group of chemicals called flavonols which have previously been shown to improve cardiovascular function and increase blood flow to the brain.

Salk Institute researcher Henriette van Praag and her colleagues found a combination of exercise and a diet of epicatechin also promoted functional changes in a part of the brain involved in the formation of learning and memory.

The findings, published in the May 30 issue of The Journal of Neuroscience, suggest a diet rich in flavonols could help reduce the effects of neurodegenerative illnesses such as Alzheimer's disease or cognitive disorders related to aging.

Van Praag and her team fed some mice a regular diet and supplemented the diet of the others with the compound. The researchers also had half the mice in each group run on a wheel for two hours a day. After a month the mice were trained to find a platform hidden in a pool of water.

Those that ran on the wheel and consumed epicatechin remembered the location of the platform for longer. These mice also had greater blood vessel growth in the dentate gyrus, the area of the brain associated with memory.

Mice that consumed the compound but did not exercise still showed enhanced memory, but not as much as those that also exercised.