Association between Dietary Flavonoid Intake and the Likelihood of Frailty in Middle-Aged and Older Adults: A Population-Based Analysis from the National Health and Nutrition Examination Survey (NHANES)

Objectives

Flavonoids are of particular interest for their antioxidant property and anti-inflammatory, and a therapeutic potential for age-related diseases has been suggested. Frailty is becoming a global public health concern due to an increasingly aging population. We aimed to evaluate the association between dietary flavonoid intake and the likelihood of frailty in middle-aged and older adults.

Design

A US nationally representative cross-sectional study.

Setting

National Health and Nutrition Examination Surveys database.

Participants

Of the 8159 adults aged 50 years and older.

Measurements

This study used data from NHANES (2007–2010 and 2017–2018). Dietary flavonoid intake data were obtained from a 24-h recall interview. Frailty was measured using a 53-item frailty index (FI) and diagnosed as FI > 0.21. We used survey-weighted logistic regression models to assess the association between flavonoid intake and odds of having frailty. The dose-response association between flavonoid intake and frailty was estimated using a survey-weighted restricted cubic spline (RCS) model.

Results

Among the 8159 adults (63.42 ± 0.20 years), 2551 (31.3%) had frailty. The RCS depicted a U-shaped association between total flavonoid intake and frailty. Compared with those in the lowest quintile (≤14.55 mg/day), participants in the fourth total flavonoid intake quintile (84.13–313.51 mg/day) had the lowest likelihood of frailty with an OR (95% CI) of 0.65 (0.51–0.84). The likelihood of frailty decreased until 220 mg/day, with 2% (0.8%–4.1%) lower odds of frailty per 10 mg higher total flavonoid intake, which increased thereafter. Similarly, the U-shaped relation with frailty was observed for five flavonoid subclasses (flavan-3-ols, flavanones, flavones, flavonols, isoflavones), while a roughly negative linear relation was observed for the other flavonoid subclass (anthocyanidins).

Conclusion

U-shaped associations with frailty for dietary intake of total flavonoids and flavonoid subclasses (flavan-3-ols, flavanones, flavones, flavonols, and isoflavones) were observed in middle-aged and older US adults.