Soy products have been commercially marketed as ‘healthy products’ since the latter half of the 20th century. Over the last decade, lots of studies have linked soy to hormonal imbalance, thyroid dysfunction, infertility and other health problems. Soy isoflavones are a group of compounds found in and isolated from the soybean. One study showed that genistein, one of several known isoflavones, led to reduced fertility and abnormal embryo development in female mice. Many isoflavones have been shown to interact with animal and human estrogen receptors, causing effects in the body similar to those caused by the hormone estrogen.
An infant exclusively fed soy formula receives the estrogenic equivalent (based on body weight) of up to five birth control pills per day. So please do not feed your baby soy infant formula, or your toddler soy foods. The effects are so potent that even pregnant women should avoid eating soy products for the safety of their unborn child. Children and babies, who are still developing, are particularly vulnerable to soy’s hormone-mimicking effects. A Lancet study showed that the daily exposure to estrogen-imitating chemicals for infants who consume soy formulas was 6-11 times higher than adults consuming soy foods. Soy also contains Phytic acid. Phytic acid stops your body from absorbing certain minerals, especially calcium, magnesium, iron, and zinc.
In another study, six women with regular menstrual cycles were given 60 grams soy protein containing 45 mg isoflavones daily. After one month, all experienced delayed menstruation. Luteinizing hormone and follicle-stimulating hormone were significantly suppressed. The effects were similar to those of Tamoxifen, an anti-estrogen drug. Regular menstruation did not resume until 3 months following the cessation of soy protein consumption.
Soy can also be damaging to the Thyroid. It contains Goitrogens. Goitrogens, found in all unfermented soy products are substances that block the synthesis of thyroid hormones and interfere with iodine metabolism, thereby interfering with normal thyroid function. This can lead to weight gain, lethargy, fatigue, hair loss and loss of libido.
It is important to differentiate between fermented soy and unfermented soy. Only fermented soy has health benefits. These foods include Natto, Miso and Tempeh. The fermentation process is what makes soy a healthy addition to your diet, as it breaks down the goitrogens, isoflavones and other harmful elements in the soy. Due to the phytoestrogens contained in soy, they should only be eaten in small amounts. Tofu is not fermented.
Not enough reasons for you to stop eating soy products? In most western countries, most of the soybeans grown are genetically modified. If soy doesn’t create enough havoc in the body GM soy definitely will. Studies have shown that third generation hamsters fed on GM soy are sterile.
Don’t think you eat much soy? Next time you go shopping, read the labels on everything you normally buy. You will be surprised. Soy is in everything. If you are eating processed foods, then you are eating soy. So avoiding all processed foods is crucial.
Whole Soy Story: The Dark Side of America’s Favourite Health Food by Kaayla Daniel
“Hormones and Behavior”; Increased Aggressive Behavior and Decreased Affiliative Behavior in Adult Male Monkeys After Long-Term Consumption of Diets Rich in Soy Protein and Isoflavones; N.G. Simon, et al.; April 2004Setchell KD, Zimmer-Nechemias L, Cai J, Heubi JE. Exposure of infants to phyto-estrogens from soy-based infant formula. Lancet 1997;350:23-7.
Cassidy A and others. Biological Effects of a Diet of Soy Protein Rich in Isoflavones on the Menstrual Cycle of Premenopausal Women. Am J Clin Nutr 1994 Sep;60(3):333-340
Dr Mercola, http://articles.mercola.com/sites/articles/archive/2010/10/13/soy-controversy-and-health-effects.aspx