Antioxidant-Rich Diets Associated with Reduced Mortality Risks： Findings from NHANES Cohort

Abstract Background The composite dietary antioxidant index (CDAI) reflects an individual's dietary intake of antioxidants. This study aimed to investigate the association between CDAI and mortality outcomes. Methods Data from 18,046 adults aged 18–80 years were analyzed from the US NHANES 2011–2018. CDAI was calculated from dietary vitamins A, C, E and minerals selenium, magnesium and zinc. All-cause and cancer mortality were ascertained through 2019. Cox models evaluated CDAI-mortality associations. Results Increasing CDAI quartiles were associated with decreasing all-cause mortality risk (high vs low Q4 vs Q1 HR 0.699, 95% CI 0.579–0.844, p < 0.001). A similar trend was observed for cancer mortality (Q4 vs Q1 HR 0.727, 95% CI 0.507–1.044, p = 0.084). Stronger associations were found in males. Conclusions Higher CDAI, reflecting greater dietary antioxidant intake, was associated with lower all-cause and cancer mortality. CDAI may be a useful tool for assessing antioxidant status and health outcomes. Further research is warranted on potential gender differences.