A team from Japan and the USA investigated the association between green tea consumption and risk of gastric cancer.
The researchers included a total of 26,311 residents of northern Japan (11,902 men and 14,409 women 40 years of age or older) in the study. Each completed a questionnaire that included questions about the frequency of green-tea consumption.
During 199,748 person-years of follow-up, 419 cases of gastric cancer (in 296 men and 123 women) were identified.
Cox regression analysis was used to estimate the relative risk of gastric cancer according to the consumption of green tea.
| No association between green-tea consumption and gastric cancer risk was found amongst 26,311 individuals.|
| New England Journal of Medicine |
The team found that green-tea consumption was not associated with the risk of gastric cancer.
The relative risks, calculated after adjustment for confounding factors, 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, 1.0, and 1.2, respectively.
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, 1.0, and 1.4.
Dr Yoshitaka Tsubono, of the Tohoku University Graduate School of Medicine, Sendai, Japan, concluded on behalf of the group, "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 this population-based, prospective cohort study in Japan, we found no association between green-tea consumption and the risk of gastric cancer."