According to a study published in Neurology, several fruits and vegetables, as well as tea and wine, are sources of antioxidant flavonols, which may delay the rate at which memory deterioration occurs.

The trial included 961 participants without dementia, with an average age of 81, and followed up for seven years. Every year the participants answered the questionnaire on their dietary habits and underwent annual tests of their cognitive and memory abilities. They were also questioned about their education, how often they exercised, and how much time they spent on brain-stimulating activities. 

The study considered the four components of flavonol: kaempferol, quercetin, myricetin, and isorhamnetin. The population was split into five equal groups depending on how many flavonols they consumed. The lowest group took about 5 mg daily, whereas the highest group took an average of 15 mg daily. The average daily dietary intake of total flavonols for the study population was around 10 mg. Researchers used a total global cognition score representing the results of 19 cognitive tests to calculate rates of cognitive decline.

The findings showed that the rate of cognitive deterioration was less by 0.4 units per decade in those with the highest consumption of kaempferol than in those who had least intake. Those who took the most quercetin had a 0.2 units per decade slower rate of cognitive decline than those who consumed the least. Furthermore, the rate of cognitive decline was 0.3 units per decade for those who consumed the most myricetin, which was lower than the rate for those who consumed the least.

The study does not establish that flavonols themselves are directly responsible for a slower rate of cognitive decline, but it does demonstrate a relationship between higher dietary flavonol intake and slower cognitive decline.

(Source: https://theprint.in/health/antioxidant-flavonols-linked-to-slower-memory-decline-study/1271192/)