Getting blueberry extract daily for eight weeks reversed some loss of balance and coordination in aging rats. And it improved the animals' short-term memory, as did strawberry and spinach extracts, researchers reported in the Journal of Neuroscience, 1999 (vol. 19, pp. 8114-8121). The 19-month-old rats were the equivalent of 65- to 70-year-old humans. They ate the human equivalent of at least a half cup of blueberries daily.

The most significant findings are the improvements in coordination and balance, the researchers say, because little else has reversed deficits in motor function. They attribute the reversals largely to improvements in nerve cell signaling in the neostriatum—an area of the brain that controls both motor and cognitive function. The same researchers earlier reported that high-antioxidant fruits and vegetables prevented some loss of function in aging rats (see April 1999 Food & Nutrition Research Briefs).

The findings hold hope for older people. Memory and motor function are among the first to go in humans as well as rats. Blueberries score highest in the ORAC assay, with strawberries and spinach in the top seven. Other high scorers include prunes, raisins, kale, blackberries and raspberries. ORAC measures the ability of foods, blood plasma and just about any chemical mix to subdue oxygen free radicals in the test tube. These oxygen radicals can damage cell membranes, DNA and other delicate machinery and are blamed for many of the dysfunctions and diseases of aging.

In the study rats, motor function starts to decline at about 12 months and is obvious by 15 months. By 19 months, the length of time these rats are able to traverse a narrow rod before losing balance normally drops from 13 seconds for a young rat to 5 seconds. After getting the blueberry extract, the rats stayed on the rod for an average 11 seconds.

Daily doses of strawberry and spinach extracts improved short-term memory about as well as the blueberry extract, but none improved long-term memory. For humans, an example of short-term memory is the ability to remember a phone number long enough to dial it.