Daily supplementation with mushroom (Agaricus bisporus) improves balance and working memory in aged rats.

Decline in brain function during normal aging is partly due to the long-term effects of oxidative stress and inflammation. Several fruits and vegetables have been shown to possess antioxidant and anti-inflammatory properties. The present study investigated the effects of dietary mushroom intervention on mobility and memory in aged Fischer 344 rats. We hypothesized that daily supplementation of mushroom would have beneficial effects on behavioral outcomes in a dose-dependent manner. Rats were randomly assigned to receive a diet containing either 0%, 0.5%, 1%, 2%, or 5% lyophilized white button mushroom (Agaricus bisporus); after 8 weeks on the diet, a battery of behavioral tasks was given to assess balance, coordination, and cognition. Rats on the 2% or 5% mushroom-supplemented diet consumed more food, without gaining weight, than rats in the other diet groups. Rats in the 0.5% and 1% group stayed on a narrow beam longer, indicating an improvement in balance. Only rats on the 0.5% mushroom diet showed improved performance in a working memory version of the Morris water maze. When taken together, the most effective mushroom dose that produced improvements in both balance and working memory was 0.5%, equivalent to about 1.5 ounces of fresh mushrooms for humans. Therefore, the results suggest that the inclusion of mushroom in the daily diet may have beneficial effects on age-related deficits in cognitive and motor function.