By Nora Simmons

If you and your partner are having trouble conceiving, a soy-rich diet may be partially to blame. A small study from the Harvard School of Public Health found that men who ate roughly half a serving of soy food a day (about 1 cup of soy milk or one serving of tofu every other day) had significantly lower sperm concentrations than men who didn’t eat soy.

Before purging your pantry, consider that Jeffrey Bland, PhD, FACN, founder of the Institute for Functional Medicine, thinks one or two individuals may have skewed the test results. “Some individuals have a stronger hormonal response to soy products; it’s similar to people who have a gluten allergy. This is the exception, not the norm.” To limit soy, substitute lentils, rice milk, and whole grains, says Jeannie Gazzaniga-Moloo, PhD, RD, and avoid products that list soy protein isolate (a more concentrated form of soy) as an ingredient.