Eating more flavonoids may slow aging and boost brain health, study finds

By Tarun Sai LomteReviewed by Susha Cheriyedath, M.Sc.Feb 20 2025

New research suggests a simple dietary change—boosting flavonoid-rich foods—can help older adults stay stronger, sharper, and more resilient as they age.

Study: Associations between flavonoid-rich food and flavonoid intakes and incident unhealthy aging outcomes in older U.S. males and females. Image Credit: DIVA.photo / Shutterstock

In a recent study published in The American Journal of Clinical Nutrition, researchers assessed associations between the intake of flavonoids and flavonoid-rich foods and aging outcomes in older adults.

Aging results from the accumulation of cellular and molecular damage, leading to a gradual reduction in physical and mental capacity, higher disease susceptibility, and death. While life expectancy has increased over time, the proportion of these added years spent in good health has been constant. Identifying the determinants of healthy aging is critical for evidence-based strategies aiming for longer and healthier lifespans.

Flavonoids represent a group of bioactive compounds in plant-based foods and have gained substantial attention for their impact on healthy aging. Abundant in apples, tea, citrus, berries, red wine, and dark chocolate, flavonoids exhibit oxidative stress-reducing, anti-inflammatory, and neuroprotective properties, suggesting these foods may contribute to alleviating physiological decline associated with age.

About the study

In the present study, researchers investigated associations between the intake of flavonoids and flavonoid-rich foods with aging outcomes. They used data from two large cohorts: the Nurses’ Health Study (NHS) and Health Professionals Follow-up Study (HPFS). The NHS recruited female nurses aged 30–55, whereas the HPFS recruited male health professionals aged 40–75.

Participants completed questionnaires about their medical history and lifestyle. Based on the questionnaire data, NHS and HPFS subjects were followed up from 1990 to 2014 and 2006 to 2018, respectively. Participants with missing data or extreme energy intake levels were excluded; only those aged 60 years or above were included in the analyses. Participants completed food frequency questionnaires (FFQs) at baseline and every four years.

Time-updated and changes in the intakes of a flavodiet score (FDS), which aggregates the intake of key flavonoid-rich foods and beverages (tea, apples, oranges, blueberries, strawberries, grapefruit, and red wine), and time-updated intakes of flavonoids and their sub-classes were computed from FFQs. Besides, participants undertook a short-form health survey (SF-36).

Frailty was assessed from SF-36 using the FRAIL scale, which considers five criteria: weight loss ≥ 5%, reduced aerobic capacity, fatigue, poor strength, and the presence of five or more chronic diseases. Mental health was assessed using multiple tools, including SF-36, the Geriatric Depression Scale (GDS-15), and the Center for Epidemiologic Studies Depression Scale (CESD-10), rather than just SF-36 alone. Physical function was assessed from SF-36. The team used multivariable-adjusted Cox proportional hazard models to evaluate associations with incident frailty, poor mental health, and physical impairment.

Findings

The analytic sample comprised 62,743 NHS and 23,687 HPFS subjects. Over the follow-up, there were 11,369, 8,944, and 22,419 incident cases of frailty, poor mental health, and physical impairment in the NHS. In the HPFS, there were 1,957, 1,669, and 4,165 incident cases of frailty, poor mental health, and physical impairment, respectively.

In the NHS, subjects with the highest FDS were never smokers, more physically active, more likely to take multivitamins, and had a lower alcohol intake but a higher energy intake than those with the lowest scores. Likewise, HPFS subjects also showed similar trends, except that those with the highest FDS had a lower body mass index (BMI) and body weight, higher alcohol consumption, and were less likely to have hypertension.

The highest FDS in the NHS was associated with a 15% reduced risk of frailty, a 12% lower risk of poor mental health, and a 12% lower risk of physical impairment compared to those with the lowest FDS. The highest intake of total flavonoids was associated with a 14% reduced risk of frailty and an 11% lower risk of poor mental health and physical impairment. However, in the HPFS, associations were weaker, with the strongest link being between a higher FDS and a reduced risk of poor mental health.

The highest intakes of flavonoid-rich foods (particularly tea, apples, blueberries, and red wine) in the NHS were associated with lower risks of all outcomes. In men (HPFS), fewer associations were observed, but tea and blueberries, as well as moderate intake of red wine, were linked to a reduced risk of poor mental health. Unlike in women, no significant associations were found between flavonoid intake and frailty or physical impairment in men.

In the NHS, the highest intakes of each flavonoid sub-class were associated with reduced risks of all outcomes. Consistently, there were fewer associations for flavonoid sub-classes in the HPFS. Further, an increase in FDS by three servings per week in the NHS was associated with an 8% lower risk of poor mental health, an 11% lower risk of frailty, and a 7% lower risk of physical impairment.

By contrast, a decrease in FDS by seven servings per week was associated with an 18% increased risk of frailty and a 7% higher risk of physical impairment in women. In men, a decrease in FDS by at least seven servings per week was linked to a 60% increased risk of poor mental health. Conversely, an increase in FDS by three servings per week was associated with a 15% lower risk of poor mental health in men.

Conclusions

In summary, habitually high flavodiet scores (FDS) and increases in flavonoid-rich food intake were associated with a modestly reduced risk of physical impairment, poor mental health, and frailty in women; however, in men, the primary benefit observed was a reduced risk of poor mental health rather than improvements in frailty or physical function.

The results indicate that flavonoid-rich foods such as tea, apples, blueberries, and red wine could be a simple strategy to support healthy aging. Importantly, the study suggests that maintaining or increasing flavonoid intake over time, rather than just habitual intake, may be crucial for preventing mental and physical decline, especially in women.

A key public health implication of this research is that increasing flavonoid-rich food intake by three servings per day could translate to a 6–11% reduction in risks of frailty, physical impairment, and poor mental health in women, and a 15% reduction in poor mental health risk in men. This highlights a practical and achievable dietary strategy for supporting healthy aging.