May reduce the risk of breast cancer in some populations

Soybeans are high in isoflavones, which are plant chemicals. Isoflavones are similar to the sex hormone estrogen and may bind weakly to estrogen receptors found on cells throughout the body. Because estrogen is considered to promote some forms of cancer, such as breast cancer, some experts feel that eating a lot of soybeans and isoflavones might be dangerous. Several observational studies have linked high consumption of soy products or isoflavones to an increased risk of breast cancer.

However, most similar research on Asian populations implies that a high diet of soybeans and soy products may lower the risk of breast cancer marginally. They also suggest that eating isoflavone-rich foods early in life may help protect against breast cancer later in life. Traditional Asian diets include more minimally processed soy foods such as tofu, tempeh, miso, and soy milk, whereas Western diets include soy-based meat substitutes or animal products with additional soy protein.