Contrary to what many companies, farmers, and our government will tell you, soy is NOT a superfood. In fact, I would argue that soy is completely unnecessary and should be avoided most of the time. Here are a few reasons why:

1. You all know that estrogen is the primary female sex hormone. What you probably don't know is that soy contains phytoestrogens (i.e. isoflavones) which are estrogen look-a-likes. These imposters are weaker than the real thing though and like to bond themselves to sex-hormone binding proteins in the blood as well as to estrogen receptor sites. This frees up the stronger, naturally produced estrogen in our bodies to take part in stronger estrogen actions in our body such as breast cancer.
2. The same isoflavones that we were just talking about are also known to inhibit certain thyroid functions in our bodies, specifically thyroid peroxidase (the production of T3 and T4). These isoflavones may even be the cause of hypothyroidism to begin with.
3. Soy products don't just mess with our hormones though. You see, soybeans are also quite high in phytic acid which is a substance that can block the uptake of essential minerals (i.e. calcium, magnesium, copper, iron, zinc) in the intestinal tract. The phytic acid level in soybeans is actually one of the highest phytate levels of any grain or legume that has been studied! Add to that the fact that the phytates found in soybeans are highly resistant to normal phytate-reducing techniques such as long, slow cooking and you have quite a dilemma on your hands. The only way to significantly reduce the phytate content of soybeans is a long period of fermentation. Some examples of fermented soy products are: miso, shoyu, tempeh, and natto.

A few additional facts on soy:

• Average consumption of soy foods in Japan and China is 10 grams (about 2 teaspoons) per day. Asians consume soy foods in small amounts as a condiment, and not as a replacement for animal foods.
• An infant exclusively fed soy formula receives the estrogenic equivalent (based on body weight) of at least 5 birth control pills per day!
• Megadoses of phytoestrogens in soy formula have been implicated in the current trend toward increasingly premature sexual development in girls and delayed or retarded sexual development in boys.
• Soy consumption can drastically reduce a man's libido!

With that being said, I don't see any need to include soy in your diet. Soy does not provide you with any nutrients that you couldn't get somewhere else. I would also like to point out that you may not consume soy directly by itself, but if you eat a lot of processed foods, you are most definitely consuming soy with every meal. Read all ingredient lists for a while and you may be surprised to find how prevalent soy truly is.

Ditch the soy! Your hormones will thank you.