Myth: Soy foods contain plant estrogens that are bad for your health

Fact: I get questioned about this on a weekly basis – more than any other topic. So I am going to take this opportunity to assure readers that the majority of scientific evidence suggests that soy consumption has health benefits. Soybeans contain isoflavones, weak estrogen-like substances made by plants. Much of the concern about soy’s safety relates to breast cancer risk, however studies consistently suggest there is no increased risk from soy foods in people either with or without breast cancer. On the contrary, some evidence suggests that consumption of soy products is protective, including this large study of breast cancer survivors which concluded that a higher consumption of soy isoflavone was associated with reduced total mortality. There have also been widely-circulated stories that soy may undermine male fertility however research, including this University of Guelph study, has not established significant effects.

Soy products contain many nutrients including protein, fibre, calcium, magnesium, potassium, riboflavin, thiamin, folate and iron. When consumed in the amounts contained in common foods like tofu, edamame (green soybeans), soy nuts and soy beverages, soy can safely be included as part of a healthy and balanced diet. The impact of taking soy supplements on a long term basis is less clear and should be avoided until more research is done.