Soy is one of those deceptive foods like sugar that is not likely to be harmful in small amounts but will contribute to a variety of health problems when consumed in excess over time. Traditionally, soy has been eaten in small amounts and only in fermented form in Asia for many hundreds and possibly a few thousand years. In small amounts, fermented soy does not appear to be detrimental to health. The modern problem is that most soy in foods today is not properly fermented and is added in abundance to so many foods that it is easy to get too much. It is also processed in ways that create additional hazardous chemicals that end up in soy products.
Proponents of soy tout it as a "health food" and laud the high protein and isoflavane content. But most of this propaganda is coming from those who are selling soy for a profit. A closer look reveals that yes, soy is high in protein and nutrients, but these nutrients are not very bioavailable because of the abundant enzyme inhibitors and anti-nutrients that are also in soy. Soy contains trypsin inhibitors and haemagglutinin which are growth inhibitors, isoflavones that are both goitrogens and phytoestrogens which interfere with the endrocrine system, and phytic acid which binds to minerals to make them undigestible. These compounds are found in other legumes and grains, but soy has much higher concentrations and that's bad news for health.
Cooking helps to slightly reduce some of the detrimental compounds, but fermentation is required to achieve the greatest reductions. Even fermentation does not eliminate them and that is why fermented soy should only be consumed in small amounts.
Long-term excess consumption of soy increases risk of thyroid problems, reduces male fertility, causes premature female sexual development, and increases risk of endrocrine related cancers including breast cancer and prostate cancer. These problems are seen not only in humans, but also in animal models.
As if these problems are not enough, also consider that most soy is now genetically modified to withstand massive amounts of toxic herbicide, which can also contaminate the soy products. Yet another reason to avoid soy!
Newest Research On Why You Should Avoid Soy
Soy: The Dark Side of America's Favorite "Health" Food
Why Babies Should Not be Fed Soy
The Ploy of Soy