Including in the daily diet foods or drinks that contain antioxidant flavonols –a type of flavonoids–, such as fruits and vegetables, tea or wine, can help delay memory deterioration, according to research that has just been published. publish in Neurology, the medical journal of the American Academy of Neurology. Flavonols are a type of flavonoid, a group of phytochemicals found in plant pigments that have beneficial health effects.
“It is exciting that our study shows that making specific dietary choices can lead to a slower rate of cognitive decline,” said study author Thomas M. Holland, MD, of Rush University Medical Center in Chicago. “Something as simple as eating more fruits and vegetables and drinking more tea is an easy way for people to play an active role in maintaining their brain health.”
The study involved 961 people with an average age of 81, without dementia, who were followed for an average of seven years and answered a questionnaire each year reporting how often they ate certain foods. In addition, they completed annual memory and cognitive tests, which included recalling lists of words and recalling numbers and putting them in the correct order. They answered questions about other factors, such as their level of education, how much time they spent in physical activities, and mentally engaging activities like reading and playing games.
Study shows association between higher amounts of flavonols in the diet and slower cognitive decline
The participants were divided into five equal groups based on the amount of flavonols in their diet. The average dietary intake of total flavonols for these individuals was approximately 10 mg per day. The group with the lowest intake ate about 5 mg per day, and the group with the highest ate an average of 15 mg per day, which is equivalent to about a cup of dark, leafy greens.
The researchers used an overall global cognition score that summarizes 19 cognitive tests to determine rates of cognitive decline. The mean score ranged from 0.5 for people without thinking problems, 0.2 for people with mild cognitive impairment, and -0.5 for people with Alzheimer’s disease.
Antioxidant and anti-inflammatory properties protect cognition
After adjusting for factors that might influence the rate of memory decline, such as gender, age, and smoking, the researchers found that the cognitive score of individuals with the highest intake of flavonols decreased at a rate of 0.4 units per decade more slowly than people whose intake was the lowest. Holland notes that this is likely due to the inherent antioxidant and anti-inflammatory properties of flavonols.
The study also divided the flavonol class into four components: kaempferol, quercetin, myricetin, and isorhamnetin. The main foods that provided the most amount of nutrient in each category were:
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Kale, beans, tea, spinach, and broccoli for kaempferol
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Tomatoes, Kale, Apples, and Tea for Quercetin
- Tea, wine, kale, oranges, and tomatoes for myricetin
- Pears, olive oil, wine, and tomato sauce for isorhamnetin
People with the highest kaempferol intake had a 0.4 unit per decade slower rate of cognitive decline compared with those in the lowest group. Individuals with the highest quercetin intake had a 0.2 unit per decade slower rate of cognitive decline compared to those in the lowest group. And people with the highest myricetin intake had a 0.3 unit per decade slower rate of cognitive decline compared with those in the lowest group. Dietary isorhamnetin was not linked to global cognition.
Holland explained that while the study shows an association between higher amounts of flavonols in the diet and slower cognitive decline, it does not prove that flavonols directly cause a slower rate of cognitive decline.
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