Many of the headlines spread across the Internet on soy would have you believe that soy contributes to cancer, contains “anti-nutrients,” and is growing C cup breasts on every male out there. Some of these, if you read past the title, do agree that soy has many potential benefits when consumed in the unprocessed forms.
This means avoiding GMO soy (this is getting more and more difficult–best best is to go organic as much as possible) and avoiding processed soy such as TVP. That means that the veggie burger or veggie dog that’s been reheated in the microwave is probably not going to do the wonderful things for you that you think it is. It means using forms of soy such as edamame, tofu, miso, tempeh and soy milk.
This also means that, to get the full advantage of soy, we may need to avoid antibiotics (there it is again–yet another damaging effect of indiscriminate antibiotic use). The isoflavones in soy can get converted in the gut to their aglycone form by the right types of bacteria. The aglycone form is believed to be the most potent and protective version of the compounds. This is likely why Asain populations who were raised on soy and have more of the correct blend of bacteria in their gut, get more protection from soy.
While soy does have some potential to affect the thyroid in some sensitive individuals (although there is some question that this is only in those with lowered iodine status), the health benefits in the published medical litarature are quite vast. Specifically, the outcomes and risk of certain hormone dependent cancers such as breast and prostate have some pretty massive protective effects.
This particular study looks at the potential of soy to protect against the radiation damage seen with treatment of prostate cancer. This may occur by preventing cancer cells from protecting themselves, leaving them more susceptible to the radiation damage, while at the same time protecting innocent bystander cells. Not a bad combination.
http://www.sciencedirect.com/science/article/pii/S0891584911002802