ABSTRACT Oxidative stress is a major contributor to chronic diseases such as cardiovascular disease (CVD) and cancer, and antioxidants may play a protective role. However, the link between overall dietary antioxidant intake, measured using the Composite Dietary Antioxidant Index (CDAI), and long‐term health outcomes remains unclear. This prospective cohort study investigated the association between CDAI and cause‐specific mortality, including CVD and cancer, as well as all‐cause mortality and CVD incidence, using data from 6484 adults (mean age: 48.38 years, 39.98% male) in the Mashhad Stroke and Heart Atherosclerosis Disorder (MASHAD) cohort. Dietary intake was evaluated using a validated food frequency questionnaire, and CDAI was calculated from six dietary antioxidants. Participants were followed for 10 years. Kaplan–Meier survival analysis showed that individuals in the third and fourth quartiles of CDAI had significantly lower cancer mortality ( p = 0.011) and cardiovascular mortality ( p = 0.021). Multivariable Cox regression revealed a significant inverse association between CDAI and cardiovascular mortality in the second (OR = 0.531; 95% CI: 0.391–0.884) and third (OR = 0.535; 95% CI: 0.321–0.892) quartiles, but not in the fourth (OR = 0.847; 95% CI: 0.537–1.337). Higher CDAI was also linked to lower cancer mortality in crude (OR = 0.424; 95% CI: 0.224–0.802), first (OR = 0.384; 95% CI: 0.198–0.747), and second (OR = 0.398; 95% CI: 0.202–0.785) models, though this association weakened after full adjustment (OR = 0.469; 95% CI: 0.165–1.331). No significant link was found between the highest CDAI quartile and all‐cause mortality ( p > 0.05). Overall, these findings suggest that moderate antioxidant intake may offer protective effects, particularly for cardiovascular outcomes.
Abdollahpour et al. (Thu,) studied this question.