Consuming foods rich in flavonols may help preserve memory and cognition over time, according to a study published in November 2022 in the journal Neurology.
This work adds to the growing body of evidence about the importance of what we eat. A diverse diet of fruits and vegetables is essential for cognitive and physical functioningsays Thomas Holland, assistant professor at the Rush University Medical Center (Chicago, United States).
Flavonols are a subclass of flavonoids, a class of compounds with anti-inflammatory properties found in onions, kale, lettuce, tomatoes, apples, grapes and berries, among others, as well as in tea and wine. (How to adopt an anti-inflammatory diet to prevent chronic diseases)
Holland and colleagues collected data from a cohort of Chicago residents of about 960 participants, with an average age of 81, who were followed for 7 years. The majority (75%) were women.
The participants completed a questionnaire each year on the frequency of their consumption of certain foods and took annual tests of cognition and memory. They also indicated their level of education, the time they spent on physical activities and mental activities such as reading and playing games.
The participants were divided into five groups based on the amount of flavonols they consumed. The group with the lowest consumption had an intake of about 5 mg and the group with the highest consumption had an intake of 15 mg, which is equivalent to one cup of green leafy vegetables.
To determine rates of cognitive decline, the researchers used a global cognition score summarizing 19 cognitive tests. The average score ranged from 0.5 for people with no cognitive problems to 0.2 for people with mild cognitive impairment and -0.5 for people with Alzheimer’s disease. (TEST: Alzheimer’s, mild cognitive impairment, normal memory loss?)
After adjusting the data for factors that may influence memory decline, the score of people with the highest flavonol intake showed a 32% decrease in the rate of cognitive decline compared to people with the lowest contribution.
Flavonols are antioxidants that neutralize free radicals that can cause cell damage, known as oxidative stress.
They also have anti-inflammatory properties. Inflammation is a natural process necessary for certain immune responses, but prolonged or excessive activation of the immune system can cause harm.
Researchers looked specifically at four types of flavonols: kaempferol, quercetin, myricetin, and isorhamnetin.
Participants with the highest intake of kaempferol, which is found in kale, beans, tea, spinach and broccoli, had a 32% reduced rate of cognitive decline compared to those with the lowest intake of kaempferol.
Those with the highest intake of quercetin, found in tomatoes, kale, apples and tea, had a 30% reduced rate of cognitive decline compared to those with the lowest intake.
Those with the highest intake of myricetin, found in wine, kale, oranges and tomatoes, had a 31% reduced rate of cognitive decline compared to those who consumed the least.
Dietary isorhamnetin was not related to cognition.
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Psychomedia with sources: American Academy of Neurology, Neurology, Medscape.
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