Higher Nutritional Adequacy Is Associated With Lower All-Cause Mortality: Findings From the J-MICC Cohort Study

Background : Although nutrient intake has been associated with mortality, little is known about the effect of nutritional balance in the diet on mortality. We evaluated the association between a nutritionally balanced diet and all-cause, cancer, and cardiovascular disease (CVD) mortality in a Japanese cohort. We hypothesized that participants with nutritionally adequate diets would have lower risks of all-cause, cancer, and CVD mortality. Methods : In the longitudinal Japan Multi-Institutional Collaborative Cohort Study, we included 65,407 participants (mean age: 55.0 years; 52.0% women) without cancer and CVD at baseline. The nutritional adequacy score, obtained using a validated food frequency questionnaire, was calculated based on the intake of eight beneficial nutrients and two nutrients to be restricted. A Cox proportional hazard model was used to estimate the hazard ratios and 95% confidence intervals of each quintile of the nutritional adequacy score, in relation to all-cause and cause-specific mortality, using the first quintile as reference. Results : After adjusting for age and other potential confounding factors, the nutritional adequacy score was linearly and significantly associated with lower all-cause, cancer, and CVD mortality risks in men (p<0.001, p=0.001, p=0.04, respectively); no association was found in women (p=0.74, p=0.50, p=0.96, respectively). Results of the subgroup analyses that excluded participants who died within 3 years of baseline and those with disease remained largely unchanged from the main results. In the Japanese population, a more nutritionally balanced diet was significantly linearly associated with a decreased all-cause mortality risk in men. Conclusions : These findings may facilitate the establishment of dietary recommendations for enhancing life expectancy in Asia.