Green tea consumption and mortality in Japanese men and women: a pooled analysis of eight population-based cohort studies in Japan

The aim of our study was to assess the association between green tea consumption and all-cause and cause-specific mortality in a pooled analysis of eight Japanese population-based cohort studies. Pooled hazard ratios (HR) and 95% confidence intervals (CI), derived from random effects models, were used to evaluate the associations between green tea consumption, based on self-report at baseline, and risk of all-cause and cause-specific mortality. During a mean follow-up of 17.3 years, among 313,381 persons, 52,943 deaths occurred. Compared with individuals who consumed < 1 cup/day, those in the highest consumption category (≥ 5 cups/day) had a decreased risk of all-cause mortality [the multivariate-adjusted HR was 0.90 (95% CI 0.87-0.94) for men and 0.82 (0.74-0.90) for women]. A similar inverse association was observed for heart disease mortality [HR 0.82 (0.75-0.90) for men, and 0.75 (0.68-0.84) for women], and cerebrovascular disease mortality [HR 0.76 (0.68-0.85) for men, and 0.78 (0.68-0.89) for women]. Among women, green tea consumption was associated with decreased risk of total cancer mortality: 0.89 (0.83-0.96) for the 1-2 cups/day category and 0.91 (0.85-0.98) for the 3-4 cups/day category. Results for respiratory disease mortality were [HR 0.75 (0.61-0.94)] among 3-4 cup daily consumers and [HR 0.66 (0.55-0.79)] for ≥ 5 cups/day. Higher consumption of green tea is associated with lower risk for all-cause mortality in Japanese, especially for heart and cerebrovascular disease. Moderate consumption decreased the risk of total cancer and respiratory disease mortality in women.