Will ingesting too much soy increase your risk of cancer? According to Dr. Jaya Juturi, Texas Health Presbyterian of Dallas oncologist and breast cancer specialist, “the long-term effects of soy are still unknown.” These unknown factors are leading more physicians, including Juturi, to advise patients against taking supplemental soy pills, especially survivors of hormonally responsive breast cancer.
The American Cancer Society recommends a moderate diet of soy-based foods for preventative health. So what’s the discrepancy? “Soy has many benefits, such as protein,” says Juturi. “However, soy is plant-derived estrogen (an organic compound called isoflavones). For people, especially cancer survivors, who eat soy-based foods and take soy supplements, the higher levels of estrogen may prove to be too much.” The results are still unknown, she stresses, but “think of it this way: We avoid microwaving plastic containers because of a potential risk. This falls under a similar category.”
It takes an inordinate amount of soy to pose a likely risk, Juturi says. “But I would avoid taking soy supplements with an unknown amount of isoflavones, particularly substances unapproved by the Federal Drug Administration.”