title: Green tea consumption and risk of stomach cancer: a meta-analysis of epidemiologic studies.
abstract: This meta-analysis investigated the quantitative association between the consumption of green tea and the risk of stomach cancer in epidemiologic studies using crude data and adjusted data. We searched MEDLINE, EMBASE and the Cochrane Review in August 2007. All the articles searched were independently reviewed and selected by 3 evaluators according to predetermined criteria. A total of 13 epidemiologic studies were included. When all the case-control and cohort studies were pooled, the odds ratios (OR) [corrected] of stomach cancer for the highest level of green tea consumption when compared with the lowest level of consumption were shown to be 1.10 (95% confidence interval (CI), 0.92-1.32) using the crude data and 0.82 (95% CI, 0.70-0.96) using the adjusted data.In the meta-analyses of case-control studies, no significant association was seen between green tea consumption and stomach cancer using the crude data (odds ratio (OR), 0.79; 95% CI, 0.58-1.07) [corrected], but green tea was shown to have a preventive effect on stomach cancer using the adjusted data (OR, 0.73; 95% CI, 0.64-0.83) [corrected]. In the meta-analyses of the recent cohort studies, the highest green tea consumption was shown to significantly increase stomach cancer risk using the crude data (RR, 1.59; 95% CI, 1.16-2.18), but no significant association between them was seen when using the adjusted data (RR, 1.04; 95% CI, 0.93-1.17). Unlike the case-control studies, no preventive effect on stomach cancer was seen for the highest green tea consumption in the meta-analysis of the recent cohort studies. Further clinical trials are needed.
authors.affiliation: Smoking Cessation Clinic, Center for Cancer Prevention and Detection, National Cancer Center, Goyang, Korea. msk@ncc.re.kr
authors.forename: Seung Kwon
authors.initials: SK
authors.lastname: Myung
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Bae
authors.forename: Seung Min
authors.initials: SM
authors.lastname: Oh
authors.forename: Yeol
authors.initials: Y
authors.lastname: Kim
authors.forename: Woong
authors.initials: W
authors.lastname: Ju
authors.forename: Joohon
authors.initials: J
authors.lastname: Sung
authors.forename: Yeon Ji
authors.initials: YJ
authors.lastname: Lee
authors.forename: Jeong Ah
authors.initials: JA
authors.lastname: Ko
authors.forename: Jong Im
authors.initials: JI
authors.lastname: Song
authors.forename: Hyuck Jae
authors.initials: HJ
authors.lastname: Choi
mesh_terms: D016022:Case-Control Studies; D015331:Cohort Studies; D004032:Diet; D006801:Humans; D012107:Research Design; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000517:prevention & control*; D013662:Tea
chemical_list: D013662:Tea