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. A recent study published in December 2005 showed that just 2 cups of tea may lower the risk of ovarian cancer by 46 percent in women.