A Japanese diet and 19-year mortality: National integrated project for prospective observation of non-communicable diseases and its trends in the aged, 1980

Few studies have examined the association between Japanese diet and mortality outcomes. We analysed the relationship between a healthy Japanese diet and all-cause and cause-specific mortality using the database from the National Integrated Project for Prospective Observation of Non-Communicable Diseases and its Trends in the Aged, 1980. At baseline in 1980, data were collected on study participants aged ≧30 years from randomly selected areas in Japan. We defined a measure of a healthy reduced-salt Japanese diet based on seven components from FFQ. The total score ranged from 0 to 7, with 0 being least healthy and 7 being most healthy. Participants were divided into approximate tertiles of dietary scores (0-2, 3 and 4-7 scores). After excluding participants with co-morbidities, we followed 9086 participants (44% men) for 19 years. There were 1823 all-cause and 654 cardiovascular deaths during the follow-up. With the dietary score group 0-2 serving as a reference, the Cox multivariate-adjusted hazard ratios for groups with scores 3 and 4-7 were 0.92 (95% CI 0.83, 1.04) and 0.78 (95% CI 0.70, 0.88) for all-cause mortality (trend P<0.0001), and 0.91 (95% CI 0.75, 1.10) and 0.80 (95% CI 0.66, 0.97) for cardiovascular mortality (trend P = 0.022). Adherence to a healthy reduced-salt Japanese diet was associated with an approximate 20% lower rate of all-cause and cardiovascular mortality.