The following benefits have been reported about Green Tea:  (note that virtually all of these can also be said about Resveratrol and Red Wine grape extracts, since they both contain highly-concentrated polyphenols)

Heart Disease

- Lowers cholesterol, blood pressure, and prevents platelet aggregation.

Diabetes

- Promotes insulin regulation and blood sugar regulation

Cancer

- Inhibits initiation, promotion, and the progression of cancer

Immune System

- Enhances immunity

Neurological and Mental Function

- Enhances memory and cognitive functions. May help prevent senility and Alzheimer’s disease