Association between adherence to the Japanese diet and all-cause and cause-specific mortality: the Japan Public Health Center-based Prospective Study

Purpose The present study aimed to examine the association between adherence to the Japanese diet and the subsequent risk of all-cause and cause-specific mortality using a large-scale cohort from settings all over Japan. Methods We analyzed data from a cohort study of 92,969 Japanese adults aged 45-74 years, covering 11 public health center areas nationwide. We collected dietary information using a validated 147-item food frequency questionnaire. Adherence to the Japanese diet consisting of eight components (high intake of rice, miso soup, seaweeds, pickles, green and yellow vegetables, fish, and green tea; low intake of beef and pork) was assessed using 8-item Japanese Diet Index (JDI8) score, with scores ranging from 0 to 8. The Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for all-cause and cause-specific mortality. Results During a median follow-up of 18.9 years, we documented 20,596 deaths. A higher JDI8 score was significantly associated with a lower risk for all-cause and cardiovascular disease (CVD) mortality. The multivariable-adjusted HR of all-cause and CVD mortality for the highest JDI8 score group (score of 6-8) versus the lowest JDI8 score group (score of 0-2) were 0.86 (95% CI 0.81-0.90,Ptrend < 0.001), and 0.89 (95% CI 0.80-0.99,Ptrend = 0.007), respectively. Conclusions Adhering to the Japanese diet, as assessed by the JDI8, was associated with a decreased risk of all-cause and CVD mortality among adults living in multiple areas across Japan.

Automated summary

The study found that adherence to the Japanese diet, as assessed by the JDI8 score, was associated with a lower risk of all-cause and cardiovascular disease mortality among adults living in various areas across Japan.