Alcohol consumption and suicide mortality among Japanese men: the Ohsaki Study.

The risk of suicide is well known to be increased among heavy alcohol drinkers. However, whether the risk is increased or decreased among light drinkers is still under debate. We investigated this association in a population-based sample of men in Japan. The Ohsaki Study was a population-based, prospective cohort study among Japanese adults aged from 40 to 79 years. Between October and December, 1994, 22,804 men in Miyagi Prefecture, Japan, completed a questionnaire on various health-related lifestyles, including alcohol drinking. During the subsequent 7 years follow-up, 73 participants committed suicide. We used the Cox proportional hazards regression model to estimate the hazard ratio (HR) for suicide mortality according to the quantity of alcohol consumed daily, with adjustment for potential confounders. There was a statistically significant positive and linear association between the amount of alcohol consumed and the risk of suicide: the multivariate HRs in reference to nondrinkers (95% confidence interval) were 1.2 (0.5-2.7), 1.5 (0.7-3.4), and 2.4 (1.2-4.6) in current drinkers who consumed /=45.6g of alcohol per day, respectively (P-trend=.016). Even after the early death cases were excluded, a significant linear association was observed between alcohol consumption and the risk of suicide, with the risk of suicide also being nonsignificantly higher among the light drinkers than among nondrinkers (multivariate HR=1.7). This prospective cohort study indicated a positive linear association between alcohol consumption and the risk of suicide, and the suicide risk among the light drinkers was not decreased as compared with that in nondrinkers.

Green tea consumption and mortality due to cardiovascular disease, cancer, and all causes in Japan: the Ohsaki study.

CONTEXT: Green tea polyphenols have been extensively studied as cardiovascular disease and cancer chemopreventive agents in vitro and in animal studies. However, the effects of green tea consumption in humans remain unclear. OBJECTIVE: To investigate the associations between green tea consumption and all-cause and cause-specific mortality. DESIGN, SETTING, AND PARTICIPANTS: The Ohsaki National Health Insurance Cohort Study, a population-based, prospective cohort study initiated in 1994 among 40,530 Japanese adults aged 40 to 79 years without history of stroke, coronary heart disease, or cancer at baseline. Participants were followed up for up to 11 years (1995-2005) for all-cause mortality and for up to 7 years (1995-2001) for cause-specific mortality. MAIN OUTCOME MEASURES: Mortality due to cardiovascular disease, cancer, and all causes. RESULTS: Over 11 years of follow-up (follow-up rate, 86.1%), 4209 participants died, and over 7 years of follow-up (follow-up rate, 89.6%), 892 participants died of cardiovascular disease and 1134 participants died of cancer. Green tea consumption was inversely associated with mortality due to all causes and due to cardiovascular disease. The inverse association with all-cause mortality was stronger in women (P = .03 for interaction with sex). In men, the multivariate hazard ratios of mortality due to all causes associated with different green tea consumption frequencies were 1.00 (reference) for less than 1 cup/d, 0.93 (95% confidence interval [CI], 0.83-1.05) for 1 to 2 cups/d, 0.95 (95% CI, 0.85-1.06) for 3 to 4 cups/d, and 0.88 (95% CI, 0.79-0.98) for 5 or more cups/d, respectively (P = .03 for trend). The corresponding data for women were 1.00, 0.98 (95% CI, 0.84-1.15), 0.82 (95% CI, 0.70-0.95), and 0.77 (95% CI, 0.67-0.89), respectively (P<.001 for trend). The inverse association with cardiovascular disease mortality was stronger than that with all-cause mortality. This inverse association was also stronger in women (P = .08 for interaction with sex). In women, the multivariate hazard ratios of cardiovascular disease mortality across increasing green tea consumption categories were 1.00, 0.84 (95% CI, 0.63-1.12), 0.69 (95% CI, 0.52-0.93), and 0.69 (95% CI, 0.53-0.90), respectively (P = .004 for trend). Among the types of cardiovascular disease mortality, the strongest inverse association was observed for stroke mortality. In contrast, the hazard ratios of cancer mortality were not significantly different from 1.00 in all green tea categories compared with the lowest-consumption category. CONCLUSION: Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer.