Ask Natural Life:
Are Soy Foods Healthy and Safe?
by Wendy Priesnitz
 Q: As a female vegetarian approaching menopause age, I eat a lot of soy products. Recently, however, I have been told that soy can increase the risk of breast cancer and can cause allergies. I thought it was a really healthy food, a good source of protein and vitamin B12, and even prevented cancer. I am now very confused. Can you help?
A: This is a controversial topic with a lot of hype from soy food companies, so we’re not surprised that you are confused. There are many studies discussing the disease-fighting potential of soy foods, as well as many to the contrary. Soybeans contain all the amino acids essential to human nutrition, which must be supplied in the diet because they cannot be synthesized by the human body. They are also a good source of fiber, B vitamins, calcium, and omega-3 essential fatty acids, all important food components. The American Heart Association recommends soy products as part of a “healthy heart” diet and in 1999, the U.S. Food and Drug Administration (FDA) approved a health claim that can be used on labels of soy-based foods to tout their heart-healthy benefits.
photo © ngarare/Shutterstock Images
The FDA allowed the health claim for soy protein in response to a petition by Protein Technologies International Inc., a leading soy producer that was acquired by DuPont in 1997. In considering the petition, the FDA reviewed data from 27 clinical studies submitted in the petition, which demonstrated soy protein’s value in lowering levels of total cholesterol and low-density lipoprotein (LDL, or “bad” cholesterol). However, research underwritten by the soy industry, which has been working hard over the past decade or so to create a market in North America, didn’t present the whole story, not surprisingly.
And, of course, vegetarians are a good market for soy products, because proponents claim it to be an excellent non-meat protein source. Unfortunately, the proponents don’t publicize research like that conducted more than 30 years ago, which found that processing soybeans renders the fragile protein content largely ineffective. A 1971 study published as “Studies on the Processing and Properties of Soymilk” in the J Sci Food Agri, found that in order to neutralize the protease inhibitors (enzymes that inhibit the digestion of protein) in soy, processors of products like soy protein isolate and textured vegetable protein must heat it to very high temperatures under pressure and for considerable time, a process that denatures the protein content. It is also known that these inhibitors may cause pancreatic disorders.
The Gerson Institute, a 30-year-old non-profit organization dedicated to healing and preventing chronic and degenerative diseases through natural therapy involving cleansing and immune system boosting, says that the positive aspects of the soybean are overshadowed by their potential for harm. In his classic book, A Cancer Therapy - Results of 50 Cases, Dr. Max Gerson put soy and soy products on the forbidden list of foods for Gerson Therapy patients. At the time, his greatest concerns were two items: the high oil content of soy and soy products (they can add as much as nine grams of fat per serving) and the rather high rate of allergic reactions to soy.
Soy is thought by some vegans to be a source of Vitamin B12. But there is research to indicate that Vitamin B12 analogs in soy are not absorbed and may actually increase the body’s requirement for the vitamin. Soy also apparently increases the body’s requirement for vitamin D.
Other research has found that high levels of phytic acid in soy reduce assimilation of calcium, magnesium, copper, iron and zinc. The phytic acid is not neutralized by ordinary preparation methods such as soaking, sprouting and long, slow cooking.
You have evidently heard about the research that suggests a link between soy and cancer, especially breast cancer. The cause of this potential problem are isoflavones, also called phytoestrogens because they mimic estrogen. Some studies suggest that high isoflavone levels might increase the risk of cancer, particularly breast cancer, in postmenopausal women. Research data, however, are not conclusive, and some studies show just the opposite – under some conditions, soy may help prevent breast cancer. Recent research at Belfast’s Royal Maternity Hospital indicates that isoflavones decrease the ability of a man’s sperm to fertilize eggs.
Children are at especially great danger from the phytoestrogen in soy-based formula. According to the Washington DC-based Weston A. Price Foundation, there are many adverse effects reported in the scientific literature, including thyroid disorders, asthma, digestive disorders, calcium deficiencies leading to rickets, high manganese levels leading to brain damage and endocrine disruption. A 1986 study in Puerto Rico found that use of soy formula was strongly correlated with premature maturation in girls. Even the American Academy of Pediatrics admits that early exposure to soy through commercial infant formulas may be a leading cause of soy allergies among older children and adults. The Weston A. Price Foundation is investigating instances of serious physical or medical consequences as a result of eating soy and is contemplating providing assistance to those who want to pursue legal action.
John Henkel, a member of FDA’s public affairs staff, says that although the research community has varying degrees of concern about a possible “dark side” to soy consumption, one thread runs consistently through its messages: the need for more research. A number of studies are underway, like a long-term, multi- generational study in rats by FDA’s National Center for Toxicological Research and a long-term follow-up study on the safety of soy infant formula at the National Institutes of Health.
In 2009, research by The Cornucopia Institute, a Wisconsin-based non-profit farm policy research group, exposed what they called “the dirty little secret” of the soyfoods industry. To process common soy ingredients, such as soy protein isolate and soy protein concentrate, many manufacturers immerse whole soybeans in a bath of synthetic, petroleum-based solvents, often the neurotoxic and highly-polluting hexane in products. Hexane is classified as a neurotoxin by the Centers for Disease Control and Prevention, and a hazardous air pollutant by the Environmental Protection Agency.
Fortunately for consumers, several prominent food companies have switched to cleaner soy ingredients for their soy veggie burgers and nutrition bars. And now, the Cornucopia Institute has released a new report to assist consumers and wholesale buyers in identifying brands that use hexane-extracted soy protein ingredients from those that have committed to cleaner sources.
You can save yourself and your family some potential problems by limiting soy use to fermented products like tempeh or miso. (An estimated 70 percent of supermarket products contain soy and it is a component of animal feed.) Fermentation reduces the phytate and antinutrient levels of soybeans, making their nourishment available to the human digestive system. However, make sure you are using products that originate with organic soy beans, since most of the North American soy crop is genetically modified and treated with dangerous chemicals.
Wendy Priesnitz is the Editor of Natural Life Magazine and a journalist with over 40 years of experience. She has also authored 13 books.
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