Some people claim green tea is loaded with antioxidants. However, there is new science suggesting that antioxidants are not good because our bodies seem to need to fight free radicals without special dietary supplementation beyond vitamins.
The whole matter of anxioxidants in tea resolving free radicals is controversial at this time. And, even if green tea does have antioxidant properties, it's unlikely it is in sufficient quantity to be of real value to health Steve Holman Review
Like so many other "natural" remedies, their health value is more wishful thinking from the lunatic fringe (naturopaths, homeopaths, etc) than real. If you have questions, talk with your doctor.