Flavonol Intake and Cognitive Decline in Middle-Aged Adults.

Cognitive decline occurs with age and may be slowed by dietary measures, including increased intake of dietary phytochemicals. However, evidence from large and long-term studies of flavonol intake is limited. Dietary intakes of flavonols were assessed from a large biracial study of 10,041 subjects, aged 45-64, by analysis of a food frequency questionnaire administered at visit 1 of triennial visits. Cognitive function was assessed at visits 2 and 4 with the following three cognitive performance tests: the delayed word recall test, the revised Wechsler Adult Intelligence Scale digit symbol subtest, and the word fluency test of the Multilingual Aphasia Examination. The change in each score over 6 years was calculated, and a combined standardized change score was calculated. Generalized linear models controlled for age, ethnicity, gender, education level, energy intake, current smoking, physical activity, body mass index, diabetes, and vitamin C intake. Total flavonols across quintiles of intake were positively associated with preserved combined cognitive function (P<.001). This pattern with preserved combined cognitive function was consistent for the three major individual flavonols in the diet, myricetin, kaempferol, and quercetin (each P<.001). The positive association with total flavonols was strongest for the digit symbol subtest (P<.001). In this cohort, flavonol intake was correlated with protected cognitive function over time.