Some scientists think that specific antioxidants in tea, including polyphenols and catechins, may help prevent some types of cancer. For example, some research shows that women who regularly drink black tea have a much lower risk of ovarian cancer than women who do not.
But more research is needed. So far, research has shown that black tea does not lower the risk of breast, stomach, or colorectal cancer.
Increasing evidence hints that the antioxidants in black tea may reduce atherosclerosis (clogged arteries), especially in women. It may also help lower the risk of heart attack and cardiovascular disease.