BACKGROUND
Zinc could be a target nutrient in the prevention of physical impairment and frailty in older adults due to its anti-inflammatory/antioxidant properties. However, prospective studies evaluating this inquiry are scarce. Thus, we aimed to assess the association between zinc intake and impaired lower-extremity function (ILEF) and frailty among community-dwelling older adults.
METHODS
We examined 2,963 adults aged ≥60 years from the Seniors-ENRICA cohort. At baseline (2008-2010) and subsequent follow-up (2012), zinc intake (mg/d) was estimated with a validated computerized face-to-face diet history and adjusted for total energy intake. From 2012 to 2017, the occurrence of ILEF was ascertained with the Short Physical Performance Battery, and of frailty according to the Fried phenotype criteria. Analyses were conducted using Cox proportional hazard models adjusted for relevant confounders, including lifestyle, comorbidity, and dietary factors.
RESULTS
During follow-up, we identified 515 incident cases of ILEF and 241 of frailty. Compared to participants in the lowest tertile of zinc intake (3.99-8.36 mg/d), those in the highest tertile (9.51-21.2 mg/d) had a lower risk of ILEF [fully-adjusted hazard ratio (95% confidence interval): 0.75 (0.58-0.97); p for trend: 0.03] and of frailty [0.63 (0.44-0.92); p for trend: 0.02]. No differences in the association were seen by strata of socio-demographic and lifestyle factors.
CONCLUSIONS
Higher zinc intake was prospectively associated with a lower risk of ILEF and frailty among older adults, suggesting that adequate zinc intake, that can be achieved through a healthy diet, may help preserve physical function and reduce the progression to frailty.