Soy and Male Fertility (November 2008)

Men who eat soy have fewer sperm than those who don’t, according to a new study. Soy foods such as tofu, soy milk and some veggie burgers have been shown to have many dietary benefits. But they happen to be high in isoflavones, a dietary compound that can act like estrogen. This is one reason soy is a suspected male infertility agent. The association was stronger for overweight and obese men with sperm counts on the higher end of the spectrum. Some previous studies have failed to find this link between isoflavones and sperm quantity. But, according to the authors, this is the largest human study to date. Source: Human Reproduction, July 23, 2008.