Green tea is enjoyed by millions worldwide, with Asia leading the way in consumption. As the health benefits of green tea have become better known, the use of green tea as a dietary supplement in the U.S. is on the increase. Science has learned a great deal about how green tea works. Green tea has a high content of “polyphenols”, naturally occurring compounds that exhibit an ability to protect the cardiovascular system, largely by functioning as antioxidants. But do these protective effects, as discovered in animal studies and “in vitro” (test-tube) experiments, translate to demonstrable health benefits? A large-scale population-based study was undertaken in Japan to find out.
The Ohsaki National Health Insurance Cohort Study followed 40,530 adults from 1995 to 2005. As reported in the Journal of the American Medical Association, the findings revealed that “green tea consumption was inversely associated with mortality due to all causes and due to cardiovascular disease.” In plain language, the statistics on green tea drinking showed that death rates decreased proportionally with the frequency of consumption. While overall mortality and cardiovascular mortality was lower, death due to cancer was unaffected. “Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer,” the report concludes.
Extracts of green tea are available in dietary supplements that contain concentrated amounts of polyphenols. Green tea supplements provide a convenient and practical alternative to drinking copious amounts of green tea on a daily basis.
Hsieh SR, et al. Molecular targets for anti-oxidative protection of green tea polyphenols against myocardial ischemic injury. Biomedicine 2014;4:23 Epub 2014 Nov 20.
Kuriyama S. et al. Green tea consumption and mortality due to cardiovascular disease, cancer, and all causes in Japan: the Ohsaki study. JAMA 2006 Sep 13;296:1255-65.