Following a ‘flavodiet’ protects brain health as you age, study finds | Canada Voices

Mounting research suggests that what you eat plays an important role in preventing dementia.

Greater adherence to a Mediterranean diet, for example, has been tied to a lower risk of cognitive disorders and Alzheimer’s disease. Diets plentiful in whole plant foods have been shown to offer the strongest protection against dementia in middle-aged and older adults.

Higher intakes of flavonoids, bioactive compounds found in fruits, vegetables and other plant foods, have also been associated with lower risk of dementia.

Now, a new observational study – the largest to date – supports the cognitive benefits of a flavonoid-rich diet.

According to the researchers, eating a diet with a high “flavodiet” score offers significant protection against dementia, especially in people at high genetic risk and those with hypertension or symptoms of depression.

What to know about the study, plus which flavonoid-rich foods – and how many daily servings – may provide the most benefit.

Flavonoids and brain health

Flavonoids are a family of over 5,000 plant compounds (phytochemicals). They’re categorized into subclasses based on their chemical structure, which influences their specific health properties.

Flavonoids are thought to protect brain cells by reducing inflammation, fending off free radical damage, improving blood flow to the brain and inhibiting the harmful effects of beta-amyloid, sticky proteins that form plaques and destroy brain cells.

The latest research

The study, published online Sept. 18 in the journal JAMA Network Open, investigated the relationship between daily flavonoid intake and dementia risk among 121,986 male and female participants in the U.K. Biobank, an ongoing study of more than 500,000 adults across the United Kingdom.

Participants, ages 40 to 70, provided demographic, health and lifestyle information through questionnaires and verbal interviews. Genetic testing was done to calculate participants’ genetic risk scores for dementia.

Dietary data was collected twice during the study. A unique “flavodiet” score was calculated for each participant by adding up daily intakes of key contributors to each flavonoid subclass: tea (black and green), red wine, apples, berries, grapes, oranges, grapefruit, sweet bell peppers, onions and dark chocolate.

During a follow-up period of 9.4 years, 882 participants had developed dementia.

Overall, comparing the highest to lowest flavodiet score, consuming an additional six daily servings of flavonoid-rich foods was associated with a 28-per-cent lower risk of developing dementia in all participants.

The findings also revealed that a high flavonoid diet guarded against dementia in people with a non-modifiable risk factor (genetics) and in those with modifiable risk factors (depression or hypertension).

When the researchers considered specifically participants at high genetic risk, consuming an additional six servings a day of flavonoid-rich foods was tied to a 43-per-cent lower dementia risk.

Among those who reported symptoms of depression at the study’s outset, eating six additional flavonoid-rich foods a day was associated with a 48-per-cent lower risk. And for participants with hypertension, dementia risk was reduced by 30 per cent for those who ate six extra flavonoid-rich food servings a day.

Tea, berries and red wine drive study findings

The greatest protection was seen in participants who ate at least two of the following each day: five 6.5-ounce servings of black or green tea, one 6-ounce serving of red wine and half a serving of berries (two to three tablespoons).

Doing so was linked to a 38-per-cent lower dementia risk compared to participants who didn’t achieve any of these ideal intakes, which were defined as the average daily intake of participants who were the highest consumers of these foods.

This finding was supported by the researchers’ analysis of flavonoid subclasses. Anthocyanins, flavan-3-ols and flavone subclasses, of which tea, red wine and berries are among top contributors, showed the strongest protection against dementia.

The current data on alcohol intake and dementia risk are unclear. Canada’s current health guidance is to consume no more than two standard drinks per week for minimal to low risk of negative health consequences. One standard drink is equivalent to 5 ounces of wine, 12 ounces of 5 per cent beer or 1.5 ounces of 80-proof spirits.

Finding flavonoids

According to the researchers, the study results “highlight the benefits of consuming a range of flavonoid-rich foods for lowering dementia risk.”

Include a variety of flavonoid subclasses in your regular diet. These include anthocyanins (berries, red grapes, cherries, red cabbage), flavan-3-ols (green tea, black tea, cocoa), flavonols (onions, kale, arugula, broccoli), flavanones (citrus fruit), flavones (bell peppers, celery, parsley) and isoflavones (soybeans, tofu, chickpeas, peanuts).

Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on X @LeslieBeckRD