Antioxidant in Fruits, Vegetables, Tea Linked to Lower Risk of Alzheimer’s
A new study has found that people who eat more foods with the antioxidant flavonol, which is found in nearly all fruits and vegetables, as well as tea, may be less likely to develop Alzheimer’s years later.
Flavonols are a type of flavonoid, a group of phytochemicals found in plant pigments known for its beneficial effects on health, researchers explained.
“More research is needed to confirm these results, but these are promising findings,” said study author Thomas M. Holland, M.D., of Rush University in Chicago. “Eating more fruits and vegetables and drinking more tea could be a fairly inexpensive and easy way for people to help stave off Alzheimer’s dementia.
“With the elderly population increasing worldwide, any decrease in the number of people with this devastating disease, or even delaying it for a few years, could have an enormous benefit on public health.”
The study included 921 people with an average age of 81 who did not have Alzheimer’s dementia. They filled out a questionnaire each year on how often they ate certain foods. They were also asked about other factors, such as their level of education, how much time they spent doing physical activities, and how much time they spent doing mentally engaging activities, such as reading and playing games.
The group was followed for an average of six years, with yearly tests to see if they had developed Alzheimer’s dementia.
The researchers reported they used various tests to determine that 220 people developed Alzheimer’s dementia during the study.
The researchers found that the average amount of flavonol intake in U.S. adults is about 16 to 20 milligrams per day. In the study, people in the lowest group had an intake of about 5.3 mg per day, while the highest group consumed an average of 15.3 mg per day.
The study’s findings showed that people who consumed the highest amount of flavonols were 48 percent less likely to later develop Alzheimer’s dementia than the people in the lowest group, after adjusting for genetic predisposition and demographic and lifestyle factors.
Of the 186 people in the highest group, 28 people, or 15 percent, developed Alzheimer’s dementia, compared to 54 people, or 30 percent, of the 182 people in the lowest group, according to the researchers.
The results were the same after researchers adjusted for other factors that could affect the risk of Alzheimer’s, such as diabetes, previous heart attack, stroke, and high blood pressure.
The study also broke the flavonols down into four types: isorhamnetin, kaempferol, myricetin and quercetin. The top food contributors for each category were: Pears, olive oil, wine, and tomato sauce for isorhamnetin; kale, beans, tea, spinach, and broccoli for kaempferol; tea, wine, kale, oranges, and tomatoes for myricetin; and tomatoes, kale, apples, and tea for quercetin.
According to the researchers, people who had a high intake of isorhamnetin were 38 percent less likely to develop Alzheimer’s, as well as those with a high intake of myricetin. Those with a high intake of kaempferol were 51 percent less likely to develop dementia. However, quercetin was not tied to a lower risk of Alzheimer’s dementia.
Holland noted that the study shows an association between dietary flavonols and Alzheimer’s risk, but does not prove that flavonols directly cause a reduction in disease risk.
Other limitations of the study are that the food frequency questionnaire, although valid, was self-reported, so people may not accurately remember what they eat. The majority of participants in the study were white people, so the results may not reflect the general population, the researcher added.
The study was published in Neurology, the medical journal of the American Academy of Neurology.
Wood, J. (2020). Antioxidant in Fruits, Vegetables, Tea Linked to Lower Risk of Alzheimer’s. Psych Central. Retrieved on December 3, 2020, from https://psychcentral.com/news/2020/02/01/antioxidant-in-fruits-vegetables-tea-linked-to-lower-risk-of-alzheimers/153870.html