Many components of a plant-based diet might reduce breast
cancer risk. The fiber component of fruit and vegetables, particularly
insoluble fiber, may bind with estrogens and lead to
excretion, which reduces serum estrogen concentrations (34). A
greater intake of soluble fiber, generally associated with a diet
characterized by a lower glycemic load, may help maintain lower
concentrations of glucose, insulin, and insulin-like growth factors
(35, 36). Many fruit and vegetables are also high in antioxidants
or contain phytochemicals which have been shown to inhibit the
growth of breast cancer cells (37, 38).