Nutrition studies have shown a reduced risk of developing dementia from a diet rich in foods containing flavonoids. Significant benefits were observed in those at a high genetic risk or suffering from hypertension and depression. A recent study was conducted in the UK by Amy Jennings and colleagues published in JAMA Network Open.
This included data from 121,986 adults aged 40 to 70 years recruited in the UK Biobank between 2006 and 2010. Using a 24-hour computerized dietary assessment during follow-up averaging 9.2 years, researchers assessed the participants' intake of flavonoid-rich foods. The principal outcome of interest was all-cause dementia, and researchers also investigated interactions between flavodiet scores, genetic risk, hypertension, and depressive symptoms.

The flavodiet score was established through evaluation of the level of consumption versus foods that are rich with flavonoids, namely: anthocyanins, flavonols, flavones, and flavan-3-ols, which can be found in food items such as tea, berries, and red wine. The dietary intake score was drawn from the participant's history as obtained through 24-hour dietary interviews. Researchers sorted participants into quintiles based on their flavodiet scores, the highest quintile indicating the highest consumption of flavonoid-rich foods.
• Risk of developing all types of dementia was reduced by 28% in flavodiet adherence (AHR, 0.72; 95% CI, 0.57-0.89) and increased by 24% in a comparison of flavodiet adherence.
• Individuals at high genetic risk for dementia had a 43% reduced risk with high flavodiet adherence (AHR, 0.57; 95% CI, 0.42-0.78).
• The participants with depressive symptoms had the most significant risk reduction in dementia (AHR, 0.52; 95% CI, 0.33-0.81), and it is possible that flavonoid-rich diets might be of particular benefit to this susceptible population.
• The greatest level of risk reduction was observed among those with at least 2 portions per day of the following: 5 cups of tea, 1 glass of red wine and 0.5 portions of berries.
Higher intakes of certain subclasses of flavonoids-the anthocyanins, flavan-3-ols, flavonols, and flavones-were significantly associated with a reduced risk of dementia. Foods such as tea, berries, and red wine are rich in these flavonoid compounds and were the major sources of participants' overall flavonoid intakes. Increasing daily intake of these foods may be neuroprotective and reduce the risk of dementia.
This study has shown that higher adherence to a diet rich in flavonoids is significantly associated with a lower risk of dementia, especially among subjects at high genetic risk for dementia, hypertension, and depressive symptoms.
Reference:
Jennings, A., Thompson, A. S., Tresserra-Rimbau, A., O’Neill, J. K., Hill, C., Bondonno, N. P., Kühn, T., & Cassidy, A. (2024). Flavonoid-rich foods, dementia risk, and interactions with genetic risk, hypertension, and depression. JAMA Network Open, 7(9), e2434136. https://doi.org/10.1001/jamanetworkopen.2024.34136