Association of the Oxidative Balance Score and Cognitive Function and the Mediating Role of Oxidative Stress: Evidence from the National Health and Nutrition Examination Survey (NHANES) 2011–2014

Oxidative stress is possibly related to cognitive function decline. The oxidative balance score (OBS) that combines pro- and antioxidant components from diet and lifestyle has been reported to be associated with age-related diseases. We aimed to investigate the association between OBS and cognitive function in older adults and explore whether oxidative stress mediated this relationship. A total of 1745 adults aged ≥60 y were included in the National Health and Nutrition Examination Survey (NHANES) 2011–2014. Cognitive function was measured using 4 tests: the immediate recall test, delayed recall test, animal fluency test (AFT), and digital symbol substitution test (DSST). Weighted multivariate linear regression and restricted cubic splines (RCS) analyses were used to evaluate the association between OBS and cognitive function, and mediation analysis was used to test the indirect effect of oxidative stress indicators on the association. The OBS was positively associated with AFT, DSST, and global cognitive function in older adults, and the beta estimates (95% CI) were 0.015 (0.008, 0.034), 0.009 (0.002, 0.025), and 0.030 (0.024, 0.074), moreover, RCS results suggested an approximately linear dose–response relationship between the OBS and these 3 tests. The highest quartiles of these 3 tests were also significantly correlated with OBS. Albumin, uric acid, and serum 25(OH)D concentrations were significant mediators of the relationship between OBS and cognitive function, and the overall mediation effect proportion was 36% when included in 1 model. OBS was positively correlated with cognitive function in older adults, and albumin, uric acid, and serum 25(OH)D concentrations could be the driving mediators of the association. The findings emphasize the importance of a healthy, antioxidant diet and lifestyle that contribute to cognitive function. J Nutr 20xx;x:xx.