Note: Most researches agree that soy eaten in its organic, whole food form (such as edamame and soybean sprouts) is healthful, but proponents of soy foods do not generally issue such limited recommendations. And Dr. Mercola goes even farther, to say that only fermented soy is healthful.
One big argument for soy foods that I often hear is, "The Asian world eats lots of soy and they have the healthiest hearts." Well, "lots" is actually a misconception. In the Cornell study of China, cited in an article on the WAPF website, it was found that the Chinese ate only about 2 teaspoons of soy per day--in other words, a condiment amount. Interestingly, the Japanese daily diet contains a third the amount of soy protein as the US's FDA recommended amount--which recommendation was made, incidentally, after one study funded by the soy industry.
As explained in the above article, high amounts of soy in the diet can cause disruptions in hormones, the endocrine system, and thyroid function, and can really cause problems for infants fed soy-based formulas. (Another article discusses how these formulas are similar to birth control pills!) But the problems don't stop there. Yet one more article I found at WAPF debunks the most popular soy myths. Here are a few of them:
- Are processed in a way that denatures proteins and increases levels of carcinogens,
- Do not supply needed B12 to the vegetarian diet because "the compound that resembles vitamin B12 in soy cannot be used by the human body; in fact, soy foods cause the body to require more B12,"
- Do not prevent osteoporosis because they "cause deficiencies in calcium and vitamin D,"
- Do not prevent heart disease because "in some people, consumption of soy foods will lower cholesterol, but there is no evidence that lowering cholesterol improves one's risk of having heart disease" (one of the biggest myths in modern medicine, that most people think is fact--a topic for another post),
- Do not enhance mental ability. In fact, "In Japanese Americans tofu consumption in mid-life is associated with the occurrence of Alzheimer's disease in later life,"
- Contain a lot of MSG because "free glutamic acid or MSG, a potent neurotoxin, is formed during soy food processing and additional amounts are added to many soy foods."
If you're interested in learning more, you can check out these other websites:
The Great Soy Controversy by Real Food Forager (which includes links to 3 studies)
Dr. Mercola (which includes a video about the dangers of soy)
Wise Woman Tradition (which includes what soy foods to avoid and which ones are actually healthful)