Green Tea Consumption and Stomach Cancer Risk: A Meta-Analysis.
- Author:
Hyunseok KANG
1
;
Sun Young RHA
;
Kyung Won OH
;
Chung Mo NAM
Author Information
1. Department of Epidemiology and Biostatistics, Graduate School of Public Health, Yonsei University, Seoul, Korea.
- Publication Type:Meta-Analysis ; Original Article
- Keywords:
Green tea;
Stomach cancer;
Meta-analysis
- MeSH:
Bias (Epidemiology);
Population Characteristics;
Stomach;
Stomach Neoplasms;
Tea
- From:Epidemiology and Health
2010;32(1):e2010001-
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.
