There is a long article about soy in menshealth, here are two snippets from that article.
http://www.menshealth.com/nutrition/...gative-effects
James Price's breasts had been painful and swollen. It looked as if gum balls were implanted underneath each nipple. The slightest touch triggered throbs.
For Price, a retired U.S. Army intelligence officer who once flew attack helicopters in Vietnam, these changes were more than just physically uncomfortable. "Men aren't supposed to have breasts," he says today in a quiet Texas drawl. "It was like my body was feminizing."
A lean and wiry man, the breast development stood in stark contrast to the rest of his body. But it was not Price's only symptom. His beard growth had slowed, he'd lost hair from his arms, chest, and legs, and he'd stopped waking up with morning erections. "My sexual desire disappeared," he says. "My penis—I won't say it atrophied, but it was so flaccid that it looked very small in comparison with the way it used to be. Even my emotions changed."
...............................filler here.......................
"Of course, most medicines have side effects. And when you consume soy protein, you're actually courting the Mr. Hyde side of two natural drugs: genistein and daidzein. Both act so similarly to estrogen that they're known as phytoestrogens (plant-produced estrogens). Soybeans couldn't care less about human sex characteristics—genistein and daidzein may have evolved to act as chemical defenses against fungi and grazing animals. (They aren't very effective deterrents, apparently, since soy meal is widely used to feed livestock.) But when humans consume these compounds in high enough quantities, they may experience gender-bending nightmares like James Price's. What's more, studies of these phytoestrogens in leading peer-reviewed medical journals suggest that even lower doses—such as the amount in the 25-gram soy protein target cited by the FDA—have the potential to wreak hormonal havoc."
Edit: The guy was drinking like 3 qts of soymilk a day lol