Associations of Nutritional Health Risk With Cognitive Function in Older Korean Adults: The Mediating Roles of Lower Body Strength and Depression

Aim Malnutrition is associated with cognitive decline, but the causal relationship is unknown. This population‐based study of 9885 older Korean adults investigated the mediating roles of lower body strength (LBS) and depression on the relationship between nutritional health risk (NHR) and cognitive function. Methods Cognitive function was evaluated using the Korean version of the Mini‐Mental State Examination. NHR was assessed using the Nutrition Screening Checklist. LBS was measured with a modified sit‐to‐stand test. Depression was defined as having a Korean version of the Geriatric Depression Scale (GDS‐K) score of ≥ 8. A mediation analysis was conducted to determine the relationship between NHR and cognitive function, with LBS and depression acting as mediators. Results Age ( β = −0.120, p < 0.001), education ( β = 0.226, p < 0.001), smoking ( β = −0.502, p < 0.001), income ( β = 0.001, p < 0.001), marital status ( β = −0.244, p < 0.001), NHR ( β = −0.421, p < 0.001), LBS ( β = −1.90, p < 0.001), and GDS‐K ( β = −0.043, p = 0.0502) were significant predictors of cognitive function. NHR has an indirect effect on cognitive function through its impact on LBS ( β = −0.013, 95% confidence interval [CI] = −0.020 to −0.006) and GDS‐K ( β = −0.017, 95% CI = −0.033 to −0.007). NHR is also directly related to cognitive function ( β = −0.067, 95% CI = −0.103 to −0.030). Conclusions Our study findings suggest that NHR is associated with cognitive decline both directly and indirectly via its impact on LBS and GDS‐K.