Researchers conducted an analysis on 40,530 Japanese citizens in northeastern Japan for 11 years to determine if green tea has protective effects against all-cause mortality, cardiovascular diasease and cancer. Tea consumption was collected using a self-administered questionnaire and was found to be inversely associated with all-cause mortality and to cardiovascular disease mortality. Compared with participants who consumed less than 1 cup/day, 5 or more cups/day reduced all-cause and CVD mortality by 16% and 26%, respectively. This effect was stronger in women than in men. No mortality reduction was observed for cancer.
Kuriyama, S; Shimazu, T. et al. Green Tea Consumption and Mortality Due to Cardiovascular Disease, Cancer and All Causes in Japan:the Ohsaki Study. JAMA, Sept. 13, 2006. Vol. 296, No. 10.