Yang Gong, Shu Xiao-Ou, Li Honglan, Chow Wong-Ho, Ji Bu-Tian, Zhang Xianglan, Gao Yu-Tang, Zheng Wei
Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville TN 37232-2587, USA.
Cancer Epidemiol Biomarkers Prev. 2007 Jun;16(6):1219-23. doi: 10.1158/1055-9965.EPI-07-0097.
Tea and its constituents have shown anticarcinogenic activities in in vitro and animal studies. Epidemiologic studies, however, have been inconsistent. We prospectively evaluated the association between green tea consumption and colorectal cancer (CRC) risk in a cohort of 69,710 Chinese women aged 40 to 70 years. Information on tea consumption was assessed through in-person interviews at baseline and reassessed 2 to 3 years later in a follow-up survey. During 6 years of follow-up, 256 incident cases of CRC were identified. The multivariate relative risk of CRC was 0.63 (95% confidence interval, 0.45-0.88) for women who reported drinking green tea regularly at baseline compared with nonregular tea drinkers. A significant dose-response relationship was found for both the amount of tea consumed (Ptrend = 0.01) and duration in years of lifetime tea consumption (Ptrend = 0.006). The reduction in risk was most evident among those who consistently reported to drink tea regularly at both the baseline and follow-up surveys (relative risk, 0.43; 95% confidence interval, 0.24-0.77). The inverse association with regular tea drinking was observed for both colon and rectal cancers. This study suggests that regular consumption of green tea may reduce CRC risk in women.
在体外和动物研究中，茶及其成分已显示出抗癌活性。然而，流行病学研究结果并不一致。我们前瞻性评估了69710名年龄在40至70岁的中国女性队列中绿茶消费与结直肠癌（CRC）风险之间的关联。通过在基线时的面对面访谈评估茶消费信息，并在2至3年后的随访调查中重新评估。在6年的随访期间，确定了256例结直肠癌新发病例。与不定期饮茶者相比，在基线时报告经常饮用绿茶的女性患结直肠癌的多变量相对风险为0.63（95%置信区间，0.45 - 0.88）。对于茶的消费量（P趋势 = 0.01）和终生饮茶年限（P趋势 = 0.006）均发现了显著的剂量反应关系。在基线和随访调查中均持续报告经常饮茶的人群中，风险降低最为明显（相对风险，0.43；95%置信区间，0.24 - 0.77）。在结肠癌和直肠癌中均观察到与经常饮茶的负相关关系。这项研究表明，经常饮用绿茶可能会降低女性患结直肠癌的风险。
