Total and specific polyphenol intakes in midlife are associated with cognitive function measured 13 years later.J Nutr. 2012 Jan; 142(1):76-83.JN
Polyphenols, and in particular flavonoids, are omnipresent plant-food components displaying biochemical properties possibly beneficial to brain health. We sought to evaluate the long-term association between total and class-specific polyphenol intake and cognitive performance. Polyphenol intake was estimated using the Phenol-Explorer database applied to at least six 24-h dietary records collected in 1994-1996 as part of the SU.VI.MAX (Supplémentation en Vitamines et Minéraux Antioxydants) study. The cognitive performance of 2574 middle-aged adults participating in the cohort was assessed in 2007-2009 using the following four neuropsychological tests: phonemic and semantic fluency, the RI-48 Cued Recall test, the Trail Making test, and Forward and Backward Digit Span. Inter-correlations among the test scores were estimated with principal component analysis. Associations between polyphenol intake and cognition were assessed by multivariate linear regression and ANCOVA. In multivariate models, high total polyphenol intake was associated with better language and verbal memory (P = 0.01) but not with executive functioning (P = 0.09). More specifically, intake of catechins (P = 0.001), theaflavins (P = 0.002), flavonols (P = 0.01), and hydroxybenzoic acids (P = 0.0004) was positively associated with language and verbal memory, especially with episodic memory assessed by the RI-48 test. In contrast, negative associations between scores on executive functioning and intake of dihydrochalcones (P = 0.01), catechins (P = 0.01), proanthocyanidins (P = 0.01), and flavonols (P = 0.01) were detected. High intake of specific polyphenols, including flavonoids and phenolic acids, may help to preserve verbal memory, which is a salient vulnerable domain in pathological brain aging. Further investigations are needed to clarify the observed negative associations regarding executive functioning.