A new study published September 2006 in the Journal of the American Medical Association (JAMA) showed that drinking green tea reduces the risk of all-cause mortality.
The study, which took place in Japan, followed 40,530 adults between the ages of 40 and 79 years who did not have a history of stroke, coronary heart disease, or cancer, for up to 11 years for all-cause mortality and up to 7 years for cause-specific mortality.
Intake of green tea, and other information such as diet, alcohol and tobacco use, weight and physical activity we ascertained from questionaires. Researchers compared those who drank 5 or more cups of green tea a day to those who drank one or few cups a day.
Interestingly, the green tea seemed to have a greater protective effect in women than in men. Women who drank 5 or more cups of green tea a day had a 23 percent lower risk of all-cause mortality, than those who drank just one cup of green tea a day or less. As well, women who drank 5 cups of green tea had a 31 percent lower risk of dying of cardiovascular disease (CVD) than those who only drank one cup of green tea a day or less. Stroke mortality for women was reduced by an astounding 62 percent. In men, all-cause mortality was reduced by 12 percent, cardiovascular disease mortality was reduced by 22 percent and stroke mortality was reduced by 42 percent.
Kuriyama, S., T. Shimazu, et al. (2006). "Green tea consumption and mortality due to cardiovascular disease, cancer, and all causes in Japan: the Ohsaki study." JAMA 296(10): 1255-65.