I’m unsure how soy has managed to get such a bad reputation. But there is no doubt that the internet has contributed to the idea that soy is bad for our health and increases the risk of cancer, thyroid problems, breasts on men and maybe even hangnails. It is a topic that I frequently have to address both in the community and in my office.
First, let me make a few things clear. We are talking about unprocessed soy, so NOT veggie burgers, TFP (textured vegetable protein) or soy hot dogs (do people seriously buy these?). Given the concern over the genetic modification of foods (GMO), organic or at least non-GMO soy is the only way to go. So soy milk, tofu, edemame, tempeh.
I can tell you that the overwhelming majority of research studies on soy are very positive, especially as it relates to breast cancer. Lowering the risk and improving outcomes have been shown consistently in the medical literature. This particular study found a whopping 54% lower risk of dying after a breast cancer diagnosis. Wow! Too bad they don’t post this type of info all over the Komen 3-day sites.
The compounds believed to provide the most benefits in soy are the isoflavones. We also know that isoflavones are converted by specific bacteria in the gut to the aglycone form, which is the most protective form. This is likely why some populations get greater benefits from soy (like Asian women raised in Asia) because they have consumed soy over a lifetime and the bacteria in their gut have adapted. It is also likely that antibiotics will destroy these beneficial bacteria–yet another downside to society’s heavy dependence on antibiotics for every little sniffle.