Dietary intake of flavonols associated with global cognitive decline and multiple cognitive abilities

Authors: HOLLAND, THOMAS - Rush University; AGARWAL, PUJA - Rush University; WANG, YAMIN - Rush University; DHANA, KLODIAN - Rush University; LEURGANS, SUE - Rush University; SHEA, KYLA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; BOOTH, SARAH - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; RAJAN, KUMAR - Rush University; SCHNEIDER, JULIE - Rush University; BARNES, LISA - Rush University

Submitted to: Neurology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2022
Publication Date: 2/14/2023
Citation: Holland, T.M., Agarwal, P., Wang, Y., Dhana, K., Leurgans, S.E., Shea, K., Booth, S.L., Rajan, K.B., Schneider, J.A., Barnes, L.L. 2023. Dietary intake of flavonols associated with global cognitive decline and multiple cognitive abilities. Neurology. https://doi.org/10.1212/WNL.0000000000201541.
DOI: https://doi.org/10.1212/WNL.0000000000201541

Interpretive Summary: Flavonols are bioactive compounds found in fruits and vegetables that have anti-oxidant properties and have been in implicated brain health. The purpose of this study was to evaluate the association of dietary flavonol intake with cognition in 961 older adults over 7 years of follow-up. Cognition was assessed annually using a battery of tests that evaluated multiple cognitive domains. Higher total flavonol intakes were associated with a slower rate of overall cognitive decline. When individual flavonol constituents were analyzed separately, higher intakes of kaempferol and quercetin were associated with a slower rate of overall cognitive decline. Kaempferol is abundant in green leafy vegetables and quercetin is found in apples, onions, and berries. These findings suggest higher intakes of flavonol-rich foods may help maintain cognition in older adulthood.

Technical Abstract: Background and Objective: Previous research has examined the association between cognition and flavonoids: bioactives found in many foods and known to possess anti-inflammatory and antioxidant properties. We extend this research by investigating associations of dietary intakes of total flavonols and constituents (kaempferol, quercetin, myricetin, isorhamnetin) on the change in cognitive performance in global cognition, episodic memory, semantic memory, visuospatial ability, perceptual speed, and working memory. Methods: The study was conducted using 961 participants (aged 60 to 100 years) of the Rush Memory and Aging Project, a prospective cohort of community-dwelling Chicagoans who were followed for an average of 6.9 years. Diet was assessed by a validated semi-quantitative food frequency questionnaire. Cognitive performance was assessed annually with a battery of 19 standardized tests. Flavonol intake was analyzed as a continuous variable using linear mixed effects models. Cognitive domain scores were regressed on baseline calorie-adjusted flavonol variables. Results: Higher dietary intake of total flavonols and flavonol constituents were associated with a slower rate of decline in global cognition and multiple cognitive domains. In continuous models adjusted for age, sex, education, APOE-:4, late life cognitive activity, physical activity, and smoking, total flavonol intake was associated with slower decline in global cognition beta estimate=0.004 (95% CI=0.001, 0.006), episodic memory beta=0.004 (95% CI: 0.002, 0.006), semantic memory beta=0.003 (95% CI: 0.001, 0.007), perceptual speed beta=0.003 95% CI: 0.001, 0.004), and working memory beta=0.003 (95% CI: 0.001, 0.005) and marginally associated with visuospatial ability beta=0.001 (95% CI: -0.001, 0.003). Analyses of individual flavonol constituents demonstrated that intakes of kaempferol and quercetin were associated with slower global cognitive decline [beta=0.01 (95% CI: 0.006, 0.02) and beta=0.004 (95% CI: 0.0005, 0.007)], respectively. Myricetin and isorhamnetin were not associated with global cognition. Conclusion: Dietary intakes of total flavonols and several constituents may slow decline in global cognition and multiple cognitive domains with older age.