Protective effects of berry polyphenols against age-related cognitive impairment

Abstract

A growing body of evidence suggests that dietary interventions may delay or halt the progression of age-related health disorders and cognitive decline. Among the components of the human diet, polyphenols from berries are essential micronutrients that have been particularly studied for improving cognitive functions. In the present review, we highlight the health impact of major polyphenolic classes found in berries: flavanols, anthocyanins and stilbenes, focusing on resveratrol. The reports of beneficial effects of berry consumption on age-related cognitive decline and associated neurobiological processes in animals and human are underscored. We then discuss the potential benefit of each category of polyphenols on memory impairment and in neurodegenerative diseases. Berry polyphenols improve several types of memory and have a global effect on brain plasticity, partly through their antioxidant activity and/or their effect on neuronal signal transduction and neuroinflammation. Interestingly, accumulated bioavailability data suggest that most polyphenols, or at least key metabolites, can access the brain in sufficient concentrations. Collectively, the data accumulated so far suggest that dietary polyphenols can modulate brain health and function, and strengthen the importance of fruit consumption for a healthy brain aging and the prevention of age-related diseases. However, further preclinical work is needed to determine the most neuroactive nutraceutical formulations, whether through the diet or supplement, to subsequently design and perform informative clinical trials.