Campbell cites the work and words of some of the leading breast cancer research groups in the world: “there is overwhelming evidence that estrogen levels are a critical determinant of breast cancer risk.” Estrogen directly participates in the cancer process and tends to indicate the presence of other female hormones that play a role in breast cancer risk. Increased levels of estrogen and related hormones are a result of the consumption of typical Western diets, high in fat and animal protein and low in dietary fiber.
Earlier onset of puberty and later onset of menopause adds eight or nine reproductive years of blood estrogen exposure to American women compared to Chinese women, who have only one fifth rate of breast cancer of American women. The idea that breast cancer is centered on estrogen exposure is profound because diet plays a major role in establishing estrogen exposure. This suggests that the risk of breast cancer is preventable if we eat foods that will keep estrogen levels under control.
In other words, eating a diet that's rich in whole, plant-based foods with little to no animal-based foods reduces risk of getting breast cancer.
- Campbell, T.C., and Campbell, T.M. The China Study, Dallas, BenBella Books, Inc., 2006, p. 159-161.