Green tea consumption and gastric cancer in Japanese: a pooled analysis of six cohort studies. Issue 10 (7th June 2009)

• Record Type: Journal Article
• Authors: Inoue, M; Sasazuki, S; Wakai, K; Suzuki, T; Matsuo, K; Shimazu, T; Tsuji, I; Tanaka, K; Mizoue, T; Nagata, C; Tamakoshi, A; Sawada, N; Tsugane, S
• Is Part Of: Gut. Volume 58:Issue 10(2009)
• Page Start: 1323
• Page End: 1332
• Publication Date: 2009-06-07
• Subjects: Gastroenterology -- Periodicals; 616.33
• DOI: 10.1136/gut.2008.166710
• Languages: English
• ISSNs: 0017-5749

Abstract

Abstract : Background: Previous experimental studies have suggested many possible anti-cancer mechanisms for green tea, but epidemiological evidence for the effect of green tea consumption on gastric cancer risk is conflicting. Objective: To examine the association between green tea consumption and gastric cancer. Methods: We analysed original data from six cohort studies that measured green tea consumption using validated questionnaires at baseline. Hazard ratios (HRs) in the individual studies were calculated, with adjustment for a common set of variables, and combined using a random-effects model. Results: During 2 285 968 person-years of follow-up for a total of 219 080 subjects, 3577 cases of gastric cancer were identified. Compared with those drinking <1 cup/day, no significant risk reduction for gastric cancer was observed with increased green tea consumption in men, even in stratified analyses by smoking status and subsite. In women, however, a significantly decreased risk was observed for those with consumption of ⩾5 cups/day (multivariate-adjusted pooled HR = 0.79, 95% confidence interval (CI) = 0.65 to 0.96). This decrease was also significant for the distal subsite (HR = 0.70, 95% CI = 0.50 to 0.96). In contrast, a lack of association for proximal gastric cancer was consistently seen in both men and women. Conclusions: Green tea may decrease the risk of distal gastric cancer in women.