Sweetpea, soy is not meant to be consumed in that way. The only 'safe' soy is fermented soy, like tofu etc. I found a website which articulates it better than I could.

1.
Soy’s loaded with oxalic acid. Think kidney stones–not to mention heart problems, immune deficiency, brain hiccups, etc. 2. Another part of soy’s manifest charms is phytates, which throw a monkey wrench into absorbing protein–along with the vital minerals calcium, iron, zinc and magnesium. We don’t go very far, very well without a goodly supply of protein and minerals.
3. And the phytates are not alone! Soy is estrogenic, so called because it mimics estrogen–keeping the real thing from its proper role whilst causing estrogen dominance–male or female. It can cause premature puberty in little girls, lifelong low testosterone for little boys, breasts in men and a closetful of symptoms in women. Estrogen is part of endocrine function, and when it’s out of whack, the rest of the endocrine system ends up in the ditch, too.
Plus, soy interferes with thyroid function. Big time. Soy can cause hypothyroid problems all by itself.
5. And soy excites our brain to death. Literally. Which can play havoc with memory. And throw our bodies into a tailspin, inviting disease to come for a visit. Speaking of which, there’s some kind of connection between extreme brain excitement and autoimmune diseases. Right now it’s just an attention-getting coincidence, but research should be coming along.


We already eat too much soy as a result of eating too much processed food - soy is used as a fuller in nearly all packaged foods except for those ones sold explicitly as soy free. Most of that soy is grown in the US, where Genetically Modified Soy is common. So we already have an overload of soy in our systems and we don't need to be adding to it by drinking soy milk as well.