Results from a prospective cohort study based in Chicago were recently published in Neurology, describing the associations between dietary flavonol intake and cognitive decline. Nearly 1,000 older adults (average age 81) without dementia were followed for approximately 7 years, as part of the Rush Memory and Aging Project. Using annual validated food frequency questionnaires (self-reported) and standardized assessments of cognitive performance, a greater intake of dietary flavonols was associated with a slower rate of global cognitive decline, including multiple aspects of cognitive function, i.e., episodic, semantic, and working memory, as well as perceptual speed. These associations persisted after multivariate adjustment for factors such as age, sex, education, APOE-ɛ4, late-life cognitive activity, physical activity, and smoking. An analysis of individual flavonols found both kaempferol and quercetin to be associated with slower global cognitive decline.
Although this analysis was not able to show causality or pinpoint the mechanisms of action, flavonols such as quercetin have previously demonstrated not only anti-inflammatory and antioxidant effects, but have been shown to promote autophagy, promote mitochondrial function, and to have antitau and anti-Aβ actions. It should be emphasized that a diet rich in multiple flavonols and other compounds is likely to have multiple targets, a distinct advantage to single drug/nutrient approaches given that cognitive decline and dementia are most certainly multifactorial.