Fish and Shellfish Consumption by Type and Risks of All-Cause and Cause-Specific Mortality in the Japan Public Health...

Although numerous studies have separately examined fish and shellfish intakes, fish types, and n-3 PUFAs in relation to mortality, few studies have concurrently evaluated these factors, and findings in Asia, including in the Japanese population with high fish consumption, remain inconsistent.

The aim of this study was to investigate the associations of unsalted fish and shellfish, n-3 PUFA-rich fish, and marine-derived n-3 PUFA consumption with all-cause and cause-specific mortality in a Japanese population.

We analyzed 90,944 individuals (42,150 males and 48,794 females) from the Japan Public Health Center-based Prospective Study who completed a validated food frequency questionnaire between 1995 and 1998. Energy-adjusted intakes were categorized into quintiles. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for all-cause and cause-specific mortality using Cox proportional hazards regression models adjusted for potential confounders.

After adjusting for covariates, a nonlinear association was observed between fish and shellfish intake and all-cause mortality in females, with the lowest mortality observed in Q4 [HR = 0.92(95% CI: 0.86, 0.98), P for nonlinearity = 0.022]. In males, higher intake of unsalted fish and shellfish was associated with a lower risk of cerebrovascular disease mortality in all quintiles except Q3 [Q2: HR = 0.78 (95% CI: 0.66, 0.92); Q4: HR = 0.77 (95% CI: 0.65, 0.91); Q5: HR = 0.84 (95% CI: 0.71, 0.99), P for nonlinearity = 0.017]. For n-3 PUFA-rich fish consumption, females had lower risks of all-cause (P for linear trend = 0.012) and cerebrovascular disease (P for linear trend = 0.005) mortality.

A moderate fish and shellfish intake is associated with lower all-cause mortality in females. Higher n-3 PUFA-rich fish intake is also associated with lower cerebrovascular disease mortality in females. Among males, higher unsalted fish and shellfish intake is associated with lower cerebrovascular disease mortality. These findings suggest that different fish types may be differentially associated with mortality outcomes.