All concerns related to soy intake have been set to rest. Soy contains high levels of isoflavones—plant compounds that are similar to estrogen. This raised concerns that consuming soy might increase risk for breast and prostate cancers. But evidence does not support any increase in cancer risk related to soy foods. In fact, research from Tufts University found intake of soy foods is associated with increased survival in women with hormone-receptor-negative breast cancer, but women who have or have had breast cancer should check with their doctor before increasing soy intake. The idea that soy intake may “feminize” men has also been disproven.
If you are being treated for hypothyroidism, you should follow the advice of your healthcare professional, but the vast majority of studies agree intake of soy foods as part of a varied diet does not increase risk for thyroid issues.
Soy protein is equivalent to animal protein in amino acid make-up, and it comes with health-promoting fiber, omega-3 and omega-6 fatty acids, vitamins such as B6, thiamine, and folate, minerals including calcium and iron, and phytochemicals. Replacing less healthy choices—like red and processed meats, refined carbohydrates, and sugar-sweetened beverages—with soy foods—like tofu, edamame, and soymilk, is good for heart health, and higher intake of soy food is associated with greater variety of health-promoting gut bacteria.
