Soy has developed a reputation as a health food over the last few decades. While ancient traditional consumption of soy in asian cultures set the foundation for this perception, the reality of modern day soy in America is a far cry from this marketing narrative. The production, processing and consumption between the two is in no way similar.
Meanwhile, hundreds of studies have concluded that processed soy is associated with a long list of health problems, including digestive issues, malnutrition, thyroid dysregulation, cognitive impairment, reproductive abnormalities, immune problems, heart disease and cancer.
Soy contains many anti-nutrient compounds:
Goitrogen compounds in soy disrupt the function of iodine in the thyroid, leading to thyroid disorders, particularly hypothyroidism.
Phytic acid levels are particularly high in soybeans and block the absorption of minerals in the body, including calcium, magnesium, copper, iron and zinc.
Enzyme inhibitors in soy block trypsin, a crucial enzyme necessary for the digestion of proteins. This leads to digestive difficulties, a reduction in protein absorption and a deficiency of amino acids. Trypsin inhibition has been shown in animal studies to cause pathologies of the pancreas, including cancer.
Lectins found in soybeans called soybean agglutinin disrupt gut health and block the absorption of nutrients by “negatively affecting intestinal structure, barrier function, mucosal immune system and balance of intestinal flora.”
Genetically modified soy makes up over 93% of the soy crops in America. GMO foods have been linked to intestinal permeability and immune dysregulation. There is still very much unknown about the long-term effects of GMO food consumption.
Soy is one of the foods most heavily sprayed with pesticides, including the known-carcinogen Glyphosate, which has been linked to endocrine disruption, increases in breast cancer and non-Hodgkin lymphoma, kidney disease and DNA damage.
Isoflavones in soybeans act as phytoestrogens and have been shown to prevent ovulation and promote the growth of cancer cells. The amount of isoflavones found in less than one cup of soy milk per day (38mg) are enough to lead to hypothyroidism, with symptoms including weight gain, lethargy, constipation and fatigue. Reproductive problems, infertility, thyroid disease and liver disease have all been seen in animal models as a result of dietary soy isoflavones.
Sperm count in men who consumed the most soy were found to be 41 million sperm per milliliter lower than in men who did not consume soy, with the normal sperm count range being between 80 and 120 million/ml. Most notably, these men who had the biggest drop in sperm count were only consuming half a serving of soy per day, which is equivalent to just one cup of soy milk or one serving of soy product every other day.
Soy Protein Isolate (SPI) is the by-product of waste produced during the processing of soybeans. SPI is heavily processed in several chemical solution and high temperatures into a food-like substance and then added to an endless list of processed foods. Carcinogenic nitrites and toxic lysinoalanine are formed during processing, while actual nutrients are destroyed, most notably protein.
This is notable because SPI is then used to create Textured Soy Protein, which is what gets promoted as a healthy alternative plant protein source in place of animal protein. Artificial flavorings (including MSG), preservatives, sweeteners, emulsifiers, and synthetic nutrients are added to make these substances palatable and stable.
Fermented soy products like tempeh, natto, miso and soy sauce are the only recommended ways to consume soy. The fermentation process improves soy by degrading the phytic acids and digestive inhibitors. The phytoestrogens, however, do still remain.
Being mindful to consume only high-quality organic fermented soy products in a limited way is probably the best approach when it comes to dietary soy.