Dietary patterns and suicide in Japanese adults: The Japan Public Health Center-based Prospective Study

Abstract

Background: Although dietary patterns have been linked to depression, a frequently observed precondition for suicide, no study has yet examined the association between dietary patterns and suicide risk. Aims: To prospectively investigate the association between dietary patterns and death from suicide. Method: Participants were 40 752 men and 48 285 women who took part in the second survey of the Japan Public Health Centerbased Prospective Study (1995-1998). Dietary patterns were derived from principal component analysis of the consumption of 134 food and beverage items ascertained by a food frequency questionnaire. Hazard ratios of suicide from the fourth year of follow-up to December 2005 were calculated. Results: Among both men and women, a 'prudent' dietary pattern characterised by a high intake of vegetables, fruits, potatoes, soy products, mushrooms, seaweed and fish was associated with a decreased risk of suicide. The multivariable-adjusted hazard ratio of suicide for the highest v. lowest quartiles of the dietary pattern score was 0.46 (95% CI 0.28-0.75) (P for trend, 0.005). Other dietary patterns (Westernised and traditional Japanese) were not associated with suicide risk. Conclusions: Our findings suggest that a prudent dietary pattern may be associated with a decreased risk of death from suicide.