Dietary antioxidants have been suggested to play a protective role against chronic diseases. This prospective study aimed to examine the association between the composite dietary antioxidant index (CDAI) and the risk of type 2 diabetes (T2D), hypertension, and abdominal obesity. This prospective cohort study included 7357 adults aged ≥ 18 years who participated in the third and fourth phases of the Tehran Lipid and Glucose Study. Dietary intake was assessed using a validated 168-item food frequency questionnaire, and CDAI scores were calculated accordingly. Multivariable-adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for T2D, hypertension, and abdominal obesity across quartiles of CDAI. During the follow-up period, the incidence rates were 12.5% for T2D (mean follow-up: 10.8 ± 3.64 years), 23.4% for hypertension (mean follow-up: 10.0 ± 4.09 years), and 33.5% for abdominal obesity (mean follow-up: 10.1 ± 4.29 years). After adjustment for age, sex, physical activity, energy intake, education, marital and occupational status, smoking, and outcome-specific baseline clinical variables, higher CDAI scores were associated with a lower risk of T2D (HR = 0.68; 95% CI: 0.48–0.96; P for trend = 0.025), hypertension (HR = 0.65; 95% CI: 0.52–0.83; P for trend = 0.014), and abdominal obesity (HR = 0.53; 95% CI: 0.42–0.68; P for trend < 0.001). Higher adherence to a diet with greater antioxidant capacity, as reflected by higher CDAI scores, may be related to a reduced risk of T2D, hypertension, and abdominal obesity among Iranian adults.
Ahmadirad et al. (Sun,) studied this question.