Green Tea and the Risk of Gastric Cancer in Japan

Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
New England Journal of Medicine (Impact Factor: 55.87). 04/2001; 344(9):632-6. DOI: 10.1056/NEJM200103013440903
Source: PubMed


Although laboratory experiments and case-control studies have suggested that the consumption of green tea provides protection against gastric cancer, few prospective studies have been performed.
In January 1984, a total of 26,311 residents in three municipalities of Miyagi Prefecture, in northern Japan (11,902 men and 14,409 women 40 years of age or older), completed a self-administered questionnaire that included questions about the frequency of consumption of green tea. During 199,748 person-years of follow-up, through December 1992, we identified 419 cases of gastric cancer (in 296 men and 123 women). We used Cox regression to estimate the relative risk of gastric cancer according to the consumption of green tea.
Green-tea consumption was not associated with the risk of gastric cancer. After adjustment for sex, age, presence or absence of a history of peptic ulcer smoking status, alcohol consumption, other dietary elements, and type of health insurance, the relative risks associated with drinking one or two, three or four, and five or more cups of green tea per day, as compared with less than one cup per day, were 1.1 (95 percent confidence interval, 0.8 to 1.6), 1.0 (95 percent confidence interval, 0.7 to 1.4), and 1.2 (95 percent confidence interval, 0.9 to 1.6), respectively (P for trend=0.13). The results were similar after the 117 cases of gastric cancer that were diagnosed in the first three years of follow-up had been excluded, with respective relative risks of 1.2 (95 percent confidence interval, 0.8 to 1.8) 1.0 (95 percent confidence interval, 0.7 to 1.5), and 1.4 (95 percent confidence interval, 1.0 to 1.9) (P for trend=0.07).
In a population-based, prospective cohort study in Japan, we found no association between green-tea consumption and the risk of gastric cancer.

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    • "Chemopreventive activities of EGCG were associated with the inhibition of tumorigenic signaling including β-catenin, c-Myc, pAkt, cyclin D1, etc.84,85 However, a few studies which covered different areas in Japan did not observe a relationship between green tea consumption and stomach cancer.139,140 Several clinical trials with curcumin have been reported in GI cancers,141,142 among which curcumin could decrease lymphocytic glutathione-S-transferase86 and prostaglandin E2 production87 in patiens with colorectal cancer and reduce polyp number and size in patients with FAP.88 Resveratrol has potent anti-inflammatory and anticarcinogenic effect through mainly scavenge of free radicals, by which its unique aromatic structure.143 "
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    Gut and liver 03/2013; 7(2):137-49. DOI:10.5009/gnl.2013.7.2.137 · 1.81 Impact Factor
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    • "At the moment tea is the second most popular beverage in the world (after water) (Cheng, 2006). The detailed analysis of green tea is relevant in the terms of preventive effect on metastasis of lung, breast cancer (Ruhl et al., 2005) prevention of inflammation, thrombosis (as the reasons of primary heart attacks and cardiovascular diseases) (Tsubono et al., 2001), *Corresponding author. E-mail: "
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    • "Eighteen articles [11-13, 17, 19-32] were identified in the initial search with the above mentioned method. Six articles [16, 33-37] were identified from reference lists. "
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    ABSTRACT: Green tea has been suggested to have a chemopreventive effect against various cancers including stomach cancer. The aim of this study is to elucidate the relationship between green tea consumption and stomach cancer risk by meta-analysis. Eighteen observational studies were identified using MEDLINE, THE COCHRANE LIBRARY, RISS, and a manual search. Summary relative risks/odds ratios (RR/ORs) for the highest versus non/lowest green tea consumption levels were calculated on the basis of fixed and random effect models. Subgroup analyses were used to examine heterogeneity across the studies. The combined results indicate a reduced risk of stomach cancer with intake of green tea (RR/OR=0.86, 95% CI=0.74-1.00). Subgroup analysis with six studies that reported differences between the highest and lowest consumption levels equal to or greater than five cups/day revealed a statistically significant protective effect (RR/OR=0.68, 95% CI=0.53-0.87). Green tea appears to play a protective role against the development of stomach cancer. The results also suggest that a higher level of green tea consumption might be needed for a clear preventive effect to appear. This conclusion, however, should be interpreted with caution because various biases can affect the results of a meta-analysis.
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