Polyphenols for Brain and Cognitive Health

Polyphenols are known to influence a number of biological systems relevant to brain function. Converging evidence from epidemiology and randomized controlled trials suggests that polyphenol intake can both protect against age-related cognitive decline and enhance cognitive function (although dose and duration of intake appear critical). This research has included studies into the mood and cognitive effects of polyphenols within the diet and also on individual classes of polyphenols from sources including tea, cocoa, wine, and soy as well as nondietary botanical sources. These studies show that polyphenols can improve cognitive function and/or mood both acutely and chronically in populations with compromised cognitive function, and also in those who are cognitively intact. Recent research has revealed some of the biologically plausible systemic and central mechanisms contributing to these effects. These include benefits to cerebral blood flow and patterns of brain activation measured using functional imaging methodology. Taken together, this body of evidence suggests that polyphenols may be useful additions to lifestyle changes, which may help to offset dementia and cognitive ageing.