GREEN TEA CONSUMPTION AND THE RISK OF PANCREATIC AND COLORECTAL CANCERS

The effect of green tea drinking in reducing human cancer risk is uncl ear, though a protective effect has been reported in numerous animal s tudies and several epidemiologic investigations. Herein the hypothesis that green tea consumption may reduce the risk of cancers of the colo n, rectum and pancreas is examined in a large population-based case-co ntrol study conducted in Shanghai, China. Newly diagnosed cancer cases (931 colon, 884 rectum and 451 pancreas) during 1990-1993 among resid ents 30-74 years of age were included. Controls (n = 1,552) were selec ted among Shanghai residents and frequency-matched to cases by gender and age. Multivariate odds ratios (ORs) and 95% confidence intervals ( CIs) of each cancer associated with green tea consumption were derived after adjustment for age, income, education and cigarette smoking. Ad ditional adjustment for dietary items and body size was found to have minimal impact. An inverse association with each cancer was observed w ith increasing amount of green tea consumption, with the strongest tre nds for rectal and pancreatic cancers. For men, compared with non-regu lar tea drinkers, ORs among those in the highest tea consumption categ ory (greater than or equal to 300 g/month) were 0.82 for colon cancer, 0.72 for rectal cancer and 0.63 for pancreatic cancer, with p values for trend being 0.38, 0.04 and 0.04, respectively. For women, the resp ective ORs for the highest consumption category (greater than or equal to 200 g/month) were 0.67, 0.57 and 0.53, with the respective p value s for trend being 0.07, 0.001 and 0.008. Our findings provide further evidence that green tea drinking may lower the risk of colorectal and pancreatic cancers. (C) 1997 Wiley-Liss, Inc.