Higher Dietary Non-enzymatic Antioxidant Capacity Is Associated with Decreased Risk of All-Cause and Cardiovascular Disease Mortality in Japanese Adults

Background Few studies have assessed associations of non-enzymatic antioxidant capacity (NEAC) in the overall diet with all-cause or specific mortality, and their results have been inconsistent. Objectives The present study investigated the association between dietary NEAC and all-cause or cause-specific mortality. Methods The study was a large-scale population-based prospective cohort study in Japan consisting of 42,520 men and 50,207 women aged 44-76 y, who had no history of cancer, stroke, ischemic heart disease, or chronic liver disease. We evaluated FFQ-based dietary NEAC with use of published databases in which the NEACs of individual foods were analyzed by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays. Dietary NEAC was calculated by multiplying the estimated NEAC with the consumed amount and summing up those values for all foods, and was categorized in quartiles. We identified death and cause of death with use of residential registry and death certificates. HRs and 95% Cls for death from the second survey, which was conducted from April 1995 to December 2014 were estimated with Cox proportional hazards regression analysis. Results After 1,498,308 person-years of follow-up, 12,978 total deaths occurred. The multivariable-adjusted HRs (95% Cls) for all-cause mortality for the highest compared with the lowest quartile of FRAP and ORAC were 0.85 (0.80, 0.89) and 0.84 (0.79, 0.89), respectively. Dietary NEACs were inversely associated with mortality from cardiovascular disease (CVD), but not from cancer. The multivariable-adjusted HRs (95% Cls) for CVD for the highest compared with the lowest quartile of FRAP and ORAC were 0.83 (0.75, 0.92) and 0.79 (0.70, 0.89), respectively. Conclusions Higher dietary NEACs from FRAP and ORAC were associated with lower risk of all-cause mortality and mortality from CVD in Japanese adults.