A number of studies have found evidence that fruits and vegetables help fight age-related cognitive decline, and this has been thought to be due to their antioxidant and anti-inflammatory effects. A new study shows there may be an additional reason why polyphenols benefit the aging brain. One reason why the brain works less effectively as it gets older is that the cells (microglia) that remove and recycle biochemical debris not only fail to do their housekeeping work, but they actually begin to damage healthy cells. Polyphenols restore normal housekeeping, by inhibiting the action of a protein that shuts down the housekeeping (autophagy) process.
While many fruits and vegetables are good sources of polyphenols, berries and walnuts, and fruit and vegetables with deep red, orange, or blue colors, are particularly good.
Poulose, S. & Joseph, J. 2010. Paper presented at the 240th National Meeting of the American Chemical Society.