Flavonoid-rich foods key to healthy ageing

High consumption of flavonoid-rich foods may support healthy ageing, suggests a study that used data from the Nurses’ Health Study (NHS) and Health Professionals Follow-up Study (HPFS).

The analyses included participants from both studies who had reached ≥60 years. The final analysis comprised 62,743 females (NHS) and 23,687 males (HPFS). Participants filled out questionnaires pertaining to their lifestyle and medical history at baseline and every 2 years. They were followed from 1990 to 2014 (NHS) and from 2006 to 2018 (HPFS). [Am J Clin Nutr 2025;121:972-985]

NHS cohort

In this group, 11,369 incident cases of frailty, 22,419 incident cases of physical impairment, and 8,944 cases of poor mental health were documented over 24 years of follow-up.

Compared with participants with the lowest flavodiet scores, those with the highest scores had lower risks of developing frailty, impaired physical function, and poor mental health after multivariate adjustments (hazard ratios [HRs]_Q5vsQ1, 0.85, 0.88, and 0.88, respectively).

According to the investigators, the flavodiet score was developed as a composite measure that captures overall adherence to a diet rich in flavonoid-containing foods, providing a more holistic perspective and facilitating public health translation. [BMC Med 2023;21:181]

The highest intake of total flavonoids was also associated with lower risks of frailty, impaired physical function, and poor mental health after adjusting for multiple covariates (HRs_Q5vsQ1, 0.86, 0.89, and 0.89, respectively).

When looking at individual flavonoid-rich foods, the highest consumption of tea, red wine, blueberries, apples, and oranges/orange juice were associated with an 11–21 percent lower risk of developing frailty. The highest intakes of red wine, blueberries, apples, strawberries, and oranges/orange juice were associated with a 4–14 percent lower risk of physical impairment. The highest intakes of apples, strawberries, oranges/orange juice, and grapefruits/grapefruit juice were associated with a 10–15 percent lower risk of poor mental health.

The association between habitually high intake of flavonoid-rich fruits and lower frailty risk echoes evidence showing an inverse association between fruit intake and frailty. [Am J Clin Nutr 2020;112:1540-1546] Also, in Asian populations, regular tea intake is tied to lower frailty risk. [J Am Med Dir Assoc 2023;25:259-265.e3; Front Nutr 2022;9:987911]

“[Findings from the evaluation of flavonoid-rich foods] suggest that increasing the consumption of flavonoid-rich foods and beverages, such as tea, red wine, and fruits, during midlife may play a preventive role in delaying the onset of frailty among females,” the investigators said.

“Notably, previous evidence demonstrating the positive influence of red wine polyphenols on ageing-related declines in physical exercise in rats aligns with our findings, emphasizing the potential of flavonoids to mitigate impairments in physical function among ageing individuals,” they added.

The link between consistently high intake of flavonoid-rich fruits and lower risk of poor mental health correlates with data reflecting the benefit of fruit intake for mental health. [Nutrients 2020;12:115; Nutrients 2021;13:1447]

HPFS dataset

The documented incident cases of frailty, physical impairment, and poor mental health among males were 1,957, 4,165, and 1,669, respectively, over 12 years of follow-up.

In this cohort, moderate intakes of total flavonoids were tied to lower risk of impaired physical function (HR_Q5vsQ1, 0.88).

Lower risk of poor mental health was observed with the highest flavodiet score intake (HR_Q5vsQ1, 0.82), highest tea and blueberry intake (HRs_Q5vsQ1, 0.86 and 0.85, respectively), and moderate average red wine intake (HR_Q5vsQ1, 0.71).

Evidence indicates that tea flavonoids and their metabolites may reduce the risk of depression through multiple pathways. [Nutrients 2019;11:1361] The reduced risk of poor mental health tied to higher blueberry intake augments evidence linking cognitive and mood benefits to blueberries. [Antioxidants (Basel) 2021;10:507]

The association seen between wine intake and lower incidence of poor mental health aligns with data linking moderate wine consumption to a reduced incidence of depression, but heavy drinking could elevate risk. [BMC Med 2013;11:192]

“It is important to note that although less consistent associations were found among males in the HPFS, this should not discount the potential impact of flavonoids on ageing outcomes within this demographic,” the investigators stressed. They attributed the lack of association to the shorter follow-up time, leading to reduced statistical power and fewer events.

“Additionally, the lower prevalence of current smokers among males, in contrast to females, is noteworthy, given evidence indicating that associations between flavonoids and various health outcomes are more pronounced in smokers than nonsmokers,” they added.

Simple modifications may have a great impact

Taken together, these findings imply that habitual intake of key flavonoid-rich foods may augment healthy ageing by mitigating the risks of frailty, impaired physical function, and poor mental health.

“From a public health standpoint, a modest yet achievable adjustment, involving an increase of three servings/day in flavonoid-rich foods, translated to 6–11 percent lower risk across all three outcomes in females and 15 percent lower risk of poor mental health in males,” said the researchers.

“Overall, these findings underscore the potential for simple dietary modifications to impact overall quality of life and contribute to the optimization of healthy ageing,” they concluded.

They called for further investigations, including evaluations of sex-specific associations.