An apple a day may keep dementia away

A potent antioxidant abundant in apples and some other fruits and vegetables appears to protect brain cells against oxidative stress, a tissue-damaging process associated with Alzheimer's disease and other neurodegenerative disorders, according to a study of rat brain cells conducted by researchers at Cornell University, Ithaca, N.Y. The research adds strength to the theory that the risk of developing Alzheimer's and similar diseases may be reduced by dietary intervention.

"On the basis of serving size, fresh apples have some of the highest levels of [the antioxidant] quercetin when compared to other fruits and vegetables and may be among the best food choices for fighting Alzheimer's," contends C.Y. Lee, professor and chairman of the Department of Food Science & Technology. "People should eat more apples, especially fresh ones." He cautions that protecting against Alzheimer's using any food product is theoretical, while adding that genetics and environment also are believed to play a role in the disease. Despite these caveats, the researcher predicts that "eating at least one fresh apple a day might help."

The researchers subjected groups of isolated rat brain cells to varying concentrations of either quercetin or vitamin C. The cells then were showered with hydrogen peroxide to simulate the type of oxidative cell damage that is believed to occur with Alzheimer's. These results were compared to brain cells that similarly were exposed to hydrogen peroxide but were not pretreated with antioxidants.

Brain cells that were treated with quercetin had significantly less damage to cellular proteins and DNA than those treated with vitamin C and the cells that were not exposed to antioxidants. This demonstrates quercetin's stronger protective effect against neurotoxicity.

Even though quercetin is relatively stable during cooking, fresh apples are better sources since the compound mainly is concentrated in the skin of the fruit rather than the flesh, Lee points out. Products such as apple juice and apple sauce do not contain significant amounts of skin. In general, red apples tend to have more of the antioxidant than green or yellow ones, although any variety is a good source.

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