Currently, it appears quite possible that the two most dreaded diseases - cardiovascular disease and cancer - can be treated or prevented with the use of catechins, a group of polyphenol compounds found in tea leaves. This protective agent is found in the Australian gardens that grow tea. Some of the varieties of tea that contain catechins are White Tea, Green Tea, Oolong Tea (semi-fermented), and Black Tea (completely fermented). Black Tea and Oolong Tea are considered to be less effective for treatment because of their degrees of oxidation. 

Amongst other things, tea polyphenols help prevent deposits that narrow the arteries. Prostate cancer in men can be slowed down with a daily dose of Green Tea. Acute hepatic failure, caused by inflammation or oxidative stress, can also be healed with Green Tea.