New research does suggest that the more apples, berries and tea you consume, the lower your risk of Alzheimer’s disease and related dementias. This finding comes from a 20-year-long Tufts University study that included 2,801 people age 50 and older. It looked at their consumption of flavonoids, natural substances found in fruit and onions as well as in tea, red wine and dark chocolate. Low intake of apples, pears and tea was linked with twice the normal risk of developing dementia and low intake of blueberries, strawberries and red wine was associated with a risk that was four times higher than normal.
Study participants whose flavonoid intake was low consumed no berries, only one and a half apples and no tea per month. High intake meant consuming about 7.5 cups of blueberries or strawberries per month, eight apples and pears and 19 cups of tea.
Senior author Paul Jacques, a nutritional epidemiologist, said that with no effective drugs available for treatment of Alzheimer’s, preventing it with a healthy diet is important. He added that age 50 – the approximate age at which data from the study participants was first analyzed – isn’t too late in life to make positive dietary changes. (The risk of dementia starts to increase over age 70.) He said the study’s “take home message is, when you are approaching 50 or just beyond, you should start thinking about a healthier diet, if you haven’t already.”
First author Esra Shistar added that the study results reveal that the people who may benefit most from consuming more flavonoids are those who eat the least of the foods containing them, “and it doesn’t take much to improve levels. A cup of tea a day or some berries two or three times a week would be adequate.”
I agree that it isn’t difficult to add some tea and berries to your diet. We’ve known for some time that people who have high blood levels of homocysteine, a toxic amino acid, have twice the usual risk of developing Alzheimer’s disease. Homocysteine tends to be higher in people whose diets are high in animal protein; conversely, fruits and leafy green vegetables provide folic acid and other B vitamins that can help the body reduce homocysteine levels. It’s difficult to establish cause and effect but reducing animal protein and eating more berries and other plant foods – and drinking tea – are good for general health and may help to prevent or alleviate symptoms of Alzheimer’s.
Andrew Weil, M.D.
Paul F. Jacques et al “Long-term dietary flavonoid intake and risk of Alzheimer disease and related dementias in the Framingham Offspring Cohort.” The American Journal of Clinical Nutrition, April 20, 2020; DOI: 10.1093/ajcn/nqaa079