Abstract
BACKGROUND: Although Western studies have suggested that dietary carotenoids and flavonoids may reduce the risk of ageing-related physical frailty, evidence from prospective Asian studies is limited. We examined the association between midlife intake of these phytochemicals and risk of physical frailty among Chinese adults in Singapore. METHODS: This study included 10,738 participants from the population-based prospective cohort of the Singapore Chinese Health Study. Dietary information was collected using a validated 165-item semi-quantitative food frequency questionnaire at recruitment from 1993 to 1998 (mean age 51 years, range 45-60 years). During follow-up 3 interviews from 2014 to 2017, physical frailty was assessed using a modified version of the Cardiovascular Health Study phenotype (mean age 72 years, range 63-84 years). Multivariable logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI) for the associations between nutrient intake and physical frailty. RESULTS: Among the 10,738 participants in the current study, 58.3% were female. Over a mean (SD) follow-up period of 20 (1.9) years, 1,220 participants (11.4%) were identified as being physically frail. Higher baseline consumption of carotenoids and flavonoids were associated with lower odds of physical frailty at follow-up 3. Compared to those in the lowest quintiles, the ORs (95% CIs) for the association with physical frailty for those in the highest quintiles were 0.69 (0.55-0.85) for total carotenoids (p-trend = 0.001) and 0.80 (0.64-0.99) for total flavonoids (p-trend = 0.019). Specifically, total carotenoid intake showed significant inverse association with weakness defined by weak handgrip; the OR (95% CI) comparing extreme quintiles was 0.60 (0.49-0.72) (p-trend = 0.001). Conversely, flavonoid intake was inversely associated with slow timed-up-and-go test, with an OR (95% CI) of 0.83 (0.67-1.03) for the extreme quintiles (p-trend = 0.021). For individual nutrients, significant inverse associations between consumption and odds of physical frailty were found for alpha-carotene, beta-carotene and lutein among carotenoids, and for flavan-3-ols, flavonese and flavonols among flavonoids. CONCLUSION: Higher dietary intake of carotenoids and flavonoids during midlife may be beneficial in reducing physical frailty in later life.