Association between the composite dietary antioxidant index and metabolic syndrome: evidence from NHANES 2003-2018.

OBJECTIVE: A healthy and nutritional diet has been considered a promising approach to improve many adverse clinical outcomes. However, current evidence of the association of the intake of composite dietary antioxidants with metabolic syndrome (MetS) is limited. The current study was performed to explore the effect of the composite dietary antioxidant index (CDAI) on MetS and its components based on the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2018.

MATERIALS AND METHODS: The dietary consumption was evaluated using the 24-hour diet recall method, and a previously validated approach that included six antioxidants was used to calculate CDAI. The National Cholesterol Education Program-Adult Treatment Panel III (NCEP ATP III) was applied to evaluate MetS. ORs and 95%CIs were computed by logistic regression. The association between CDAI and MetS was determined by subgroup analyses and restricted cubic spline (RCS) regressions.

RESULTS: This study included 24,705 individuals; approximately 18,378 (74.39%) participants were determined to be without MetS and 6,327 (25.61%) with MetS. After considering all confounders, compared to individuals of the lowest quartile of CDAI, those of the highest quartile showed a 31% lower risk of MetS (OR, 0.69, 95% CI: 0.57-0.82). RCS revealed a non-linear relationship between CDAI and MetS risk.

CONCLUSIONS: A non-linear association was found between CDAI and decreased MetS risk, which indicated that selective combined intake of antioxidants could be a promising and effective approach to preventing MetS for the public.