You’ve probably heard people say, “An apple a day keeps the doctor away.” Here’s a modern version, however: “An apple a day keeps dementia away.”
A new long-term study indicates that consumption of adequate amounts of flavonoid-containing food lowers the risk of developing Alzheimer’s disease and Alzheimer’s-related disease. The study examined almost 3,000 people ages 50 or older over 20 years for consumption of foods high in flavonoids and the incidence of developing Alzheimer’s and other dementias.
Flavonoid-rich foods and drinks include apples, onions, pears, berries, wine, tea and everyone’s favorite — dark chocolate. Many plants and fruits contain flavonoids, which give the food bright colors. Flavonoids are polyphenols, and there are over 6,000 different types split into six categories: isoflavones, flavanols, flavan-3-ols, flavones, flavonones and anthocyanidins. These chemicals are powerful antioxidants that enhance immune function and reduce inflammation. Diets rich in flavonoids have positive effects on weight, cardiovascular disease, diabetes, cancer prevention and neurodegenerative diseases.
This current study focused on the impact of diet on the risk of cognitive decline in older age. The researchers used surveys and medical exams to follow this large patient group, who were part of the Framingham Heart Study. The researchers included only the patients who didn’t show cognitive decline at the start of the study.
For the study, the researchers recorded consumption of each of the six different types of flavonoids and the amount of each one consumed relative to the rest of the group. Patients in these groups were examined for flavonoid consumption and the onset of Alzheimer’s disease and Alzheimer’s-related disease.
The results were the first obtained for a long-term study examining this topic. The results showed that patients consuming low levels of flavonols had up to twice the risk of developing dementia. Flavonols are found in tea, especially green tea, pears, apples, onions and cranberries.
Those who had diets low in anthocyanins had a four-fold increase in the incidence of dementia. Anthocyanins are found in strawberries, red wine, blueberries and other red, blue or purple foods.
The scientists set the lowest level of consumption at the 15th percentile for the group, for example, this meant the patients each consumed no berries each month, 1.5 apples per month, and no tea.
The study had several limitations. The dietary data was self-reported, the study group included mostly Caucasian people and other factors such as smoking, obesity or educational levels could have influenced the results.
Even with these limitations, this study describes some important links to neurodegenerative diseases that are a major public health concern in the United States. With almost six million people living with dementia and an aging population, we welcome any and all approaches to preventing this devastating disease.
For now, eat your berries and apples and relax with a cup of tea and the occasional glass of red wine and know that you are protecting your neurological health.