Green tea contains polyphenols which give its antioxidant properties. Green tea ranks as high as or higher than many fruits and vegetables in the ORAC score, a score which measures antioxidant potential of plant-based foods.
Numerous studies have demonstrated the anti-cancer properties of polyphenols.
Some studies indeed suggested that tea's polyphenols may reduce risk of gastric, esophageal and skin cancers if one consumes 4 to 6 cups daily. Other laboratory studies have found that polyphenols help prevent blood clotting and lower cholesterol levels.
Personally I'm not sure if I can drink 4 - 6 cups of green tea daily
My patients always ask me about green tea and I always said a cup or 2 won't hurt at all - if you like the taste :-)
Take Care.