An April 2020 study, the results of which have been widely published globally, and locally by The Times, stresses the value of eating more foods rich in flavonoids to protect against dementia in general and Alzheimer’s disease in particular.
Researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University in Massachusetts, looked at 2,801 participants aged 50 and older to investigate the relationship between eating foods containing flavonoids and the risk of developing Alzheimer’s disease, and other related dementias, over a period of nearly 20 years.
Flavonoids are natural substances found in plants, fruits, and vegetables, such as pears, apples, berries, onions, and plant-based drinks like tea and wine, as well as in dark chocolate. Flavonoids have previously been linked to a wide variety of health benefits, however previous studies which have looked at the link between nutrition and dementia have usually only looked at diet over a short period of time.
The findings of the new long-term study, published in the American Journal of Clinical Nutrition, showed that participants who had a low intake of three types of flavonoids appeared to have a higher risk of dementia than those with the highest intake.
The Times reported an AFP and Relaxnews story that showed, more specifically, those with a low intake of flavonoids (found in apples, pears and tea) or a low intake of flavonoid polymers (also in apples, pears and tea) appeared to have twice the risk of developing Alzheimer’s disease and related dementias, while a low intake of anthocyanins (found in blueberries, strawberries and red wine) was associated with a four-fold risk of developing Alzheimer’s disease and related dementias.
The researchers explain that a low intake was equal to no berries per month, around one-and-a-half apples per month and no tea. A high intake was equal to around 7.5 cups of blueberries or strawberries per month, eight apples and pears per month, and 19 cups of tea per month.
“Our study gives us a picture of how diet over time might be related to a person’s cognitive decline, as we were able to look at flavonoid intake over many years prior to participants’ dementia diagnoses,” said senior author Paul Jacques.
“With no effective drugs currently available for the treatment of Alzheimer’s disease, preventing disease through a healthy diet is an important consideration.”
“Tea, specifically green tea, and berries are good sources of flavonoids,” said first author Esra Shishtar. “When we look at the study results, we see that the people who may benefit the most from consuming more flavonoids are people at the lowest levels of intake, 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,” she said.
Jacques also added that even later in life at age 50, which was the age at which the participants first had their diets analysed, it’s still not too late to make positive diet changes.
“The risk of dementia really starts to increase over age 70, and the 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,” he said.
As the largest exporter of South African apples and pears, Tru-Cape Fruit Marketing is bolstered by news of these findings. Quality Manager Henk Griessel, says scientists have known for a long time that apples and pears have many health benefits and the role that flavonoids play in reducing inflammation is especially good for brain health. “Any news that increases the consumption of apples and pears is good news for us but I like to focus on the point the lead researcher makes: in the absence of medicine to treat Alzheimer’s disease, a healthy diet is proven to help and eating just eight apples or pears a month has been shown to reduce the risk of Alzheimer’s disease.”Click on this link to read the original study in full