Soy products continue to grow in numbers along with the proven and alleged health benefits attributed to them. Though the soybean plant was originally used to replace depleted nitrogen in soil and as feed for animals, technology and mass marketing have turned soy into a "wonder food" in high demand by health conscious consumers. However, a closer look at soy reveals some serious health concerns.
Soy Protein Isolate
According to an article by Sally Fallon and Mary G. Enig, PhD., "Tragedy & Hype: The Third International Soy Symposium," soy protein isolate is made by extracting the protein from soybeans. Flavorings and preservatives are then added to improve taste. Soy isolate has 90 percent protein content versus the 70 percent protein content in soy protein, as per "Elite Fitness: Online Bodybuilding Magazine" in the article, "Whey vs. Soy---You've Been Tricked."
Health Concerns
The soybean contains enzyme inhibitors that interfere with trypsin and other enzymes required for protein metabolism. The U.S. National Library of Medicine and the National Institutes of Health, in its online article on the safety of soy products, reports that the negative side effects do not have the potential of causing permanent harm. However, the article cited above by Fallon and Enig provides compelling statements based upon referenced studies stating the seriousness of health-related issues arising from the consumption of soy products. Marian Burros' NY Times article, January 26, 2000, "Doubts Cloud Rosy News on Soy," provides statements from scientists including Dr. Daniel Sheehan, a research biologist at the F.D.A.'s National Center for Toxicological Research in Jefferson, Ark., testifying to the concerns about the effect of soy isoflavones on the endocrine system.
Additives
Truth in Labeling.org offers information on monosodium glutamate (MSG), a hidden ingredient used in the processing of soy protein isolate. It includes a link to "Industry Data and Monosodium Glutamate Toxicity" by Adrienne Samuels, Ph.D. The article cites soy producers' use of processed free glutamic acid, a component of MSG, hidden in the list of ingredients of food products, including soy protein isolate, as a serious health concern contributing to problems such as cardiac irregularities.
Research
The U.S. National Library of Medicine and the National Institutes of Health, in its list of the status of soy research on specific health issues, states the cholesterol-lowering effect of including soy in the diet as the only strongly evidenced health benefit, but qualifies the statement by telling us that the relationship of soy protein to cardiovascular improvements remains unproven.
Additional Risks
Fallon and Enig also state that genistein, an isoflavone in soybeans, may have a negative effect on the development or worsening of breast cancer. Goitrogens contained in soy affect thyroid function, while the phytic acid content can block the absorption of minerals such as calcium, magnesium, and zinc---a mineral essential to the functioning of the nervous system. Their article also addresses the questionable relationship between osteoporosis prevention and soy, due to the product's interference with calcium absorption and its lack of vitamin D.
Tags: Fallon Enig, Institutes Health, Library Medicine, Library Medicine National, Medicine National