A recent study has confirmed past research showing that women can lower their risk for breast cancer by consuming soy products.
Soy contains high levels of phytoestrogens, or plant estrogens. Soy products have been shown to lower levels of estrogen in the blood, thereby reducing an individual’s risk of estrogen-linked diseases such as breast cancer, heart disease, and osteoporosis.
Researcher Lee-Jane Lu and colleagues at the University of Texas Medical Branch in Galveston explained that higher levels of estrogen cause greater proliferation among breast cells. “This may help explain why soybean consumption seems to protect against breast cancer,” Lu explained.
Doctors have long hypothesized as to why Asian women’s risk of breast cancer is so much lower than that of Western women, and many suspected that diet might hold the clue. Western women’s fat intake is much higher than that of Asian women, who eat more fish, vegetables, and soy products.
In the recent study, three groups of women drank 36 ounces of soy milk every day for periods of between one and five months. Researchers conducted tests and found that, in each of the three groups, soy milk caused the women’s estrogen levels to decline by 30-40%. In one of the groups, women’s levels of the hormone progesterone also decreased.
Study authors urged further research to determine how much, and how often women should consume soy products.