Oolong teas are partially oxidized. This process creates a flavor between green teas (not oxidized) and black teas (fully oxidized). Oolong enthusiasts appreciate the lingering, mellow flavor. This tea is rich in antioxidant which is said to be a very strong dilator of blood vessels. As the antioxidant may help the blood flow more easily through arteries it is very useful to assist protecting against heart attacks strokes and cancer. Studies showed that women who drink oolong tea can reduce risk of ovarian cancer by 46%.