A natural compound found in blueberries, tea, grapes and cocoa may enhance memory in humans, according to a new study published in the May 30 issue of The Journal of Neuroscience. The enhancement can be even more significant in those who do physical exercise regularly.

Epicatechin, one of chemicals known as flavonols, improves cardiovascular function in people and increase blood flow in the brain, early studies have found.

In the current study, Henriette van Praag, PhD, and colleagues at the Salk Institute and Mars, Inc. found that mice that ate a diet with epicatechin and did exercise had a better memory.

The researchers found the combination of exercise and a diet with epicatechin prompted structural and functional changes in the dentate gyrus, a part of the brain involved in learning and memory.

"This finding is an important advance because it identifies a single natural chemical with memory-enhancing effects, suggesting that it may be possible to optimize brain function by combining exercise and dietary supplementation," says Mark Mattson, PhD, at the National Institute on Aging.

For the study, the researchers fed two groups of mice a typical diet with epicatechin and another without the supplement.   Half of the mice in each group run on a wheel for two hours each day.

After one month, mice were trained to find a platform hidden in a pool of water. Those who ate the diet with epicatechin remembered the location for a longer time than those who ate the diet without epicatechin.

The mice with better memory were found to have greater blood vessel growth in the dentate gyrus and developed more nerve cells.    The researchers suggest that the compound enhances the ability of the cells to communicate.

Further studies show that epicatechin and exercise together affected the expression of genes important for learning and memory and decreased the activity of genes that participate in inflammation and neurodegeneration.

The results suggest that a diet rich in flavonols may help lower the risk of neurodegenerative disease or cognitive disorders that occur during the course of aging.

"A logical next step will be to study the effects of epicatechin on memory and brain blood flow in aged animals," says van Praag, "and then humans, combined with mild exercise."

The study was supported by the US Defense Department's Defense Advanced Research Projects Agency and epicatechin was provided by Mars, which markets a flavonol-rich line of chocolate.