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
Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 Japan.
Gut. 2009 Oct;58(10):1323-32. doi: 10.1136/gut.2008.166710. Epub 2009 Jun 7.
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.
To examine the association between green tea consumption and gastric cancer.
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.
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 > or =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.
Green tea may decrease the risk of distal gastric cancer in women.
先前的实验研究提出了绿茶许多可能的抗癌机制，但关于饮用绿茶对胃癌风险影响的流行病学证据相互矛盾。
研究饮用绿茶与胃癌之间的关联。
我们分析了六项队列研究的原始数据，这些研究在基线时使用经过验证的问卷来测量绿茶饮用量。计算各研究中的风险比（HRs），并对一组共同变量进行调整，然后使用随机效应模型进行合并。
在对总共219080名受试者进行的2285968人年的随访期间，共确诊3577例胃癌病例。与每天饮用<1杯绿茶的男性相比，即使按吸烟状况和肿瘤部位进行分层分析，增加绿茶饮用量也未观察到胃癌风险有显著降低。然而，在女性中，每天饮用≥5杯绿茶的女性胃癌风险显著降低（多变量调整后的合并HR = 0.79，95%置信区间（CI）= 0.65至0.96）。在远端肿瘤部位，这种降低也很显著（HR = 0.70，95% CI = 0.50至0.96）。相比之下，无论男性还是女性，近端胃癌均未发现有相关性。
绿茶可能降低女性远端胃癌的风险。
