Eating blueberries daily improves memory and executive function. (Krikorian et al., 2022)
Preventing cognitive decline is key to reducing the risk of dementia since there is no treatment for dementia currently. Positive lifestyle changes (e.g., proper nutrition) at the beginning of midlife possibly reduce neurodegenerative changes in late life.
Blueberries contain anthocyanins and proanthocyanidins (bioactive flavonoids), among other nutritional components that may have health benefits. Krikorian et al., 2022 randomized controlled trial evaluated the effect of eating blueberries on cognitive health in 33 middle-aged adult participants with overweight and subjective cognitive decline (i.e., at risk of future dementia).
An amount equal to 0.5 cups (roughly 85g) of the whole fruit was consumed daily in the frozen powder version for 12 weeks.
Daily blueberry supplementation improved executive function, memory, and fasting insulin but did not affect blood lipids.
Reference:
Krikorian R, Skelton MR, Summer SS, Shidler MD, Sullivan PG. Blueberry Supplementation in Midlife for Dementia Risk Reduction. Nutrients. 2022 Apr 13.