Consuming a flavonoid-rich diet is associated with a reduced risk for dementia, especially among individuals with a high genetic risk, hypertension, and depressive symptoms, according to study findings published in JAMA Network Open.

Researchers conducted a prospective, population-based cohort study to explore the association between a flavonoid-rich diet and dementia risk. Dietary data from adults aged 40 to 70 were sourced from the UK Biobank. Participants completed the Oxford WebQ, a validated dietary questionnaire, as well as a series of physical and biological assessments. The primary outcome was incident all-cause dementia. Multivariable Cox proportional hazards regression models were used to determine the associations between incident all-cause dementia and genetic risk, hypertension, and depressive symptoms.

A total of 121,986 participants (mean age, 56.1; women, 55.6%; White, 96.6%) were included in the study. A median 4.3 servings per day of flavonoid-rich foods, of which a median 2.7 servings per day were attributable to tea, were reported by participants. Over the course of a median follow-up of 9.4 years, a total of 882 cases of incident dementia occurred.

These findings suggest that simple dietary changes of increasing intakes of commonly consumed flavonoid-rich foods and drinks may lower dementia risk.

A mean difference of 6.2 servings per day of flavonoid-rich foods was reported between participants in the highest (quintile 5) and lowest (quintile 1) quintiles of the flavodiet score. Participants in the highest vs lowest quintiles of the flavodiet score were more physically active (median 1334 vs 1023 total excess metabolic equivalents), had a lower body mass index (BMI; median 25.8 vs 26.7 kg/m2), and experienced less socioeconomic deprivation (18.6% vs 23.8%).

Overall, participants with the highest vs lowest flavodiet scores had a lower risk for dementia (adjusted hazard ratio [aHR], 0.72; 95% CI, 0.57-0.89; P =.03).

Flavodiet score was not associated with dementia risk after tea, red wine, and berries were removed. Participants who met at least 2 vs 0 of the ideal intakes for tea, red wine, and berries had a lower dementia risk (aHR, 0.62; 95% CI, 0.46-0.84).

A higher (quintile 5) vs lower (quintile 1) flavodiet score was associated with a lower risk of developing dementia among participants at high genetic risk (aHR, 0.57; 95% CI, 0.42-0.78; P =.01), with depressive symptoms (aHR, 0.52; 95% CI, 0.31-0.81; P =.01), and with hypertension (aHR, 0.70; 95% CI, 0.52-0.94; P =.03), according to the results of stratified analyses.

Higher intakes (quintile 5 vs 1) of flavonoid subclasses were associated with a lower dementia risk, including:

  • Anthocyanins (aHR, 0.78; 95% CI, 0.62-0.97; P =.03);
  • Flavan-3-ols (aHR, 0.72; 95% CI, 0.58-0.89; P =.002);
  • Flavanols (aHR, 0.73; 95% CI, 0.59-0.91; P =.01); and,
  • Flavones (aHR, 0.71; 95% CI, 0.56-0.90; P =.03).

Study limitation include the reliance on self-reported dietary data, reduced generalizability of results to more diverse populations, and potential residual or unmeasured confounding.

“These findings suggest that simple dietary changes of increasing intakes of commonly consumed flavonoid-rich foods and drinks may lower dementia risk,” the study authors concluded.