Relationship between Composite Dietary Antioxidant Index and Aging

Background: Numerous studies have demonstrated a close relationship between antioxidant-rich diets and comorbidities as well as mortality. However, the relationship between such diets and aging remains unclear. The purpose of this study was to investigate the association between the Composite Dietary Antioxidant Index (CDAI) and aging. Methods: All participants were from the National Health and Nutrition Examination Survey (NHANES) 2001–2010. Phenotypic age was calculated using a formula and subtracted from the chronological age to determine the aging. When the phenotypic age exceeded the chronological age, it was considered as aging. A weighted logistic regression model was employed to explore the relationship between CDAI and aging. Restricted cubic splines (RCSs) were used to examine the potential nonlinear relationship between them. Subgroup analysis and joint analysis were conducted to explore the effect of modifiers in these relationships. Results: A total of 19,212 participants (weighted: 165,285,442 individuals) were included in this study. The weighted logistic regression model showed a significant correlation between CDAI and the risk of aging (OR = 0.90, 95% CI: 0.84–0.96). RCS analysis revealed an L-shaped dose–response relationship between CDAI and the risk of aging. Subgroup analysis indicated that the association between CDAI and aging was more pronounced in middle-aged individuals and non-smokers. The joint analysis demonstrated that although smoking accelerated aging among participants, a high CDAI diet could still offset these damages. Conclusions: The association between high CDAI and reduced risk of aging is particularly significant in young and middle-aged individuals and non-smokers. Consuming foods rich in CDAI components may potentially lower the risk of aging.