Study Links Antioxidant Flavonol With Lower Risk of Alzheimer’s

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“An apple a day keeps the doctor away,” may ring a bit more true after a recent study by researchers at Rush University Medical Center.

While eating fruits and vegetables already has proved to keep people healthy in their everyday lives, the Rush researchers show it may also help the mind as a person ages. Specifically, it may aid in the prevention of Alzheimer’s disease dementia.

People who eat or drink more foods with flavonol, which is found in nearly all fruits and vegetables, plus tea and wine, may be less likely to develop Alzheimer’s dementia, according to the Rush researchers. They published the results of their study in the Jan. 29 online issue of Neurology.

“More research is needed to confirm these results, but these are promising findings,” said study author Thomas M. Holland, MD, of the Rush Institute for Healthy Aging. “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.”

Participants monitored over several years

Flavonols are a type of flavonoid, a group of phytochemicals found in plant pigments. They are known for their beneficial effects on health due to their antioxidant and anti-inflammatory properties.

A total of 921 people with an average age of 81 participated in the Neurology study. These participants did not have Alzheimer’s dementia when starting the study.

Participants filled out a questionnaire each year about how often they ate certain foods. They were also asked about other factors such as education, physical activities and how much time they spent doing mentally engaging activities.

Participants were tested yearly for an average of six years to see if they had developed Alzheimer’s dementia. Over the duration of the study, 220 people developed the disease. Participants then were divided into five groups based on their flavonol consumption.

The study found that participants in the group with the highest flavonol consumption were 48% less likely to develop Alzheimer’s dementia later on in life than participants with the lowest level. Of the 186 people in the highest group, 28 people, or 15%, developed Alzheimer’s dementia, compared to 54 people, or 30%, of the 182 people in the lowest group.

The researchers adjusted for genetic predisposition, demographic and lifestyle factors. The results were the same after researchers adjusted for other factors that could affect the risk of Alzheimer’s dementia, such as diabetes, heart attack, stroke and high blood pressure.

Are these foods on your grocery list?

In the study, Holland also broke down the flavonols into four types. The following were the top food contributors in each category:

  • Isorhamnetin: pears, olive oil, wine and tomato sauce
  • Kaempferol: kale, beans, tea, spinach and broccoli
  • Myricetin: tea, wine, kale, oranges and tomatoes
  • Quercetin: tomatoes, kale, apples and tea

The study showed that people who had high intake of isorhamnetin were 38% less likely to develop Alzheimer’s. Those with high intake of kaempferol were 51% less likely to develop dementia. Those with high intake of myricetin were 38% less likely to develop dementia. 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.

The study was supported by the National Institutes of Health, National Institute on Aging and U.S. Department of Agriculture Research Service.

For more information read the study here.

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