Black tea is made from the leaves of a bush called Camellia sinensis. A process called oxidation turns the leaves from green to a dark brownish-black color. Oxidation means the leaves are exposed to moist, oxygen-rich air.
Tea manufacturers can control the amount of oxidation. Black tea is a fully oxidized tea. Green tea comes from the same plant, but is not oxidized.
Black tea is also full of healthy substances called polyphenols. Polyphenols are antioxidants that can help protect your cells from DNA damage.
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.