14 Oct 1998

A diet rich in certain fruits and vegetables is known to protect against cancer and heart disease, and now a new animal study in the October Journal of Neuroscience suggests nutrition can also stall the decline of brain function that comes with advancing age. In the study, led by James Joseph, Chief of Neuroscience at the U.S. Department of Agriculture Human Nutrition Research Center, rats were fed the daily human equivalent of a pint of strawberries or a generous spinach salad—both loaded with antioxidants—for eight months and then examined for aging-related effects on brain function. When placed in a Morris Water Maze, a common test of memory function, the rats performed signficantly better than age-matched controls. At the molecular level, these rats' neurons were protected against declines in neuronal signal transmission. Antioxidants protect cells against the ravages of free oxygen radicals. The brain is thought to be particularly vulnerable to oxygen radicals because it is relatively deficient in antioxidants, and because neurons, unlike other cells in the body, do not divide and renew themselves after birth, but must last for a human life span, accumulating damage along the way. In future studies, the researchers plan to study other antioxidant-rich foods such a blueberries, and to investigate whether antioxidants can actually reverse the effects of aging on the brain.—June Kinoshita