The Truth About Soy
Is there a dark side to soy? With many rumors circulating about soy – especially because much of America’s soy is genetically modified – it’s hard to separate fact from fiction. We hear claims that soy is nutritionally loaded, a great protein source for vegetarians and may offer protection from breast and prostate cancer, relieve menopause symptoms, prevent bone loss and lower cholesterol. On the other hand, we’re told that soy’s estrogen-like chemical components may be causing some complex problems, such as early puberty in young girls. What are we to believe?
To help clarify some of these issues, we asked local health experts for their thoughts.
Soy in the American Diet
Many Asian foods contain soy, as do a number of other foods and artificial flavorings. It’s also a very common ingredient in vegetable broth, vegetable gum and vegetable starch, says Deborah Krivitsky, a registered dietician and director of clinical nutrition at the Massachusetts Cardiovascular Disease Prevention Center at Massachusetts General Hospital in Boston. “Sometimes soy is hidden in hydrolyzed vegetable protein, textured vegetable protein, lecithin, monosodium glutamate, vegetable oil and vitamin E,” she says. “It can also be found in meat substitutes, butter substitutes, ice cream, candy and condiments.”
Soy is one of the eight most common ingredients that trigger allergic reactions, and the Food and Drug Administration (FDA) requires that it be labeled on packaged food. The other seven are milk, eggs, peanuts, tree nuts, fish, shellfish and wheat. (For a list of soy allergy symptoms and soy foods, including “hidden” sources of soy, see “Learn More” at the end of this article.)
Is Soy Safe?
“This is a topic I have pondered quite a bit,” says Kristin Sleeper, M.D., a pediatrician at Centre Pediatrics in Brookline. “From a medical standpoint the research just isn’t there yet. As a mother I tend to want to protect my kids – I personally try to avoid processed foods as best I can but give my kids edamame frequently.”
Edamame is the name for immature green soybeans, which are a good source of protein, fiber, vitamins and minerals. Sleeper also encourages offering kids tofu (bean curd) and natto (fermented soybeans, which are a traditional Japanese food).
“I think whole soybean foods certainly can be a healthy food for all ages,” says Sleeper. “But I would recommend avoidance of processed foods with isolated soy protein, as able. Again, this is a somewhat controversial subject and more studies are needed.”
Perhaps of some comfort to parents and caregivers is the fact that soy’s benefits and safety issues are being studied. The U.S. Department of Health and Human Services and the Agency for Healthcare Research and Quality released Effects of Soy on Health Outcomes: Evidence Report/Technology Assessment Number 126 in May, which summarizes research on soy and its isoflavones.
Isoflavones are compounds that make the soy plant resistant to environmental stresses like insects, disease and drought. According to Iowa State University’s Soybean Extension and Research Program website, “Soybeans are by far the most concentrated source of isoflavones in the human diet.” The site also notes, “Scientists have determined that the chemical structure of soy isoflavones is similar to that of the hormone estrogen.”
While there’s nothing particularly alarming coming from government studies, many people question soy’s safety and the safety of genetically modified organism (GMO) foods in general. Soybean production is a huge industry in the United States, and the process of genetically modifying crops in America is relatively new (since 1996).
Read More on the Concerns About GMO Soy on the Next Page!
Concerns About GMO Soy
“The genetic makeup of a soybean gives it a wide variety of uses, thus keeping it in high demand,” explains Krivitsky. “Soy was genetically modified to be able to grow more soy at a minimal cost to meet this demand and to fix any problems in the growing process. Then they found they could also modify the soybean to contain healthier components while growing it in larger quantities.”
Controversies over GMO food, says Krivitsky, “are in regard to whether food produced from genetically modified (GM) crops is safe and whether GM crops are needed to address the world’s food needs. The key areas … are whether such food should be labeled, the role of government regulators, the objectivity of scientific research and publication, and the effect of GM crops on health and the environment.” Another concern is whether the practice will contaminate the non-GMO food supply and how that can be controlled and contained.
According to the Non-GMO Project, a non-profit group that advocates establishing industry-wide standards for how to define and label non-GMO foods, “In more than 60 countries around the world, including Australia, Japan and all of the countries in the European Union, there are significant restrictions or outright bans on the production and sale of GMOs.”
Meanwhile, the U.S. Farmers & Ranchers Alliance includes this statement on its “Food Dialogues” website: “Fact: Crops from GM seeds are identical to those from non-GM seeds.” The Alliance also asserts: “The crops are tested to confirm these nutritional properties, along with being studied extensively and approved by the FDA, USDA [U.S. Department of Agriculture] and EPA [Environmental Protection Agency] to make sure they are safe for people, animals and the environment.”
Despite all these assurances, Modern Farmer magazine reports in an article titled “The Post-GMO Economy” (December 2013) that farmers are beginning to abandon the practice, not because they are opposed to GMOs, but because using conventional seed has become more productive and profitable.
More Research Needed
The health risks of eating soy “are not well established, and more research is needed to understand the relationship between specific forms of soy and doses of isoflavones on cancer risk and recurrence,” says Krivitsky. “We also need to learn more about childhood exposure to isoflavones and risk of cancer. Until more is known, if you enjoy eating soy foods, the evidence indicates that this is safe and may be beneficial.”
She adds, “It is prudent to avoid high doses of isolated soy compounds found specifically in supplements, as less is known about their health effects. As for other ‘hidden’ sources of soy proteins, the evidence to date does not suggest harm or benefit. However, if you are concerned about these products, you can choose to avoid them.”
Claims that estrogen in soy may be causing early puberty in girls or delayed physical maturation among boys are unfounded, Krivitsky maintains. As for theories that “hormones” in food may be responsible for low birth weights, infertility, sterility and birth defects, she says, “While many may argue the safety and benefits of GM soybeans, I personally would argue that it is simply too soon to know whether this is causing harm or benefit. It is difficult to establish a cause and effect relationship as there are many factors that may be contributing to each of these situations.”
Read More About Soy Formula and Soy Butter on the Next Page!
What About Soy Formula?
“Although many families turn to soy-based formulas given their commercial availability, in general, there are very few medical indications to use soy-based formula in full-term babies,” says Brittanny Boulanger, M.D., a pediatrician at Harvard Vanguard Medical Associates in Burlington. There’s no data to support the use of soy formula in babies with fussiness or colic, she adds.
Boulanger says in her practice she follows recommendations by the American Academy of Pediatrics that appear in its Pediatrics journal article “Use of Soy Protein-Based Formulas in Infant Feeding,” a 2008 clinical report updated from a 1998 report.
While Boulanger acknowledges “soy formula is an option for families that are vegetarian and prefer this in lieu of cow milk-based formula,” she stresses “soy formula is never recommended for preterm infants as it lacks the appropriate nutrition that preemies need.”
Confusion often exists about what is “the best option for infants with a diagnosed cow milk protein allergy,” Boulanger explains. “Some families – and even clinicians for that matter – will trial soy formula in this setting. However, given the risk of concurrent soy allergy, it is recommended that these babies use a hydrolyzed protein formula instead.” (Hydrolyzed means the milk protein is broken down to modify its allergenic properties.)
Sleeper concurs, “I typically don’t recommend soy formula for my patients. … If breastfeeding isn’t possible then milk-based formula is the next best choice. If an infant ends up having severe reflux or milk protein allergy, I trial an extensively hydrolyzed formula.”
Peanut Butter, Soy Butter or SunButter?
About which to choose, Sleeper responds, “I think it is likely equal at this point. Soy butter uses whole soybean; usually it isn’t a processed food, so I probably wouldn’t take issue with it. SunButter [made from sunflower seeds] is also a good option for those peanut-allergic kids.”
Says Krivitsky, “I would select the one that the child likes, making sure it doesn’t contain trans fats.”
As always, if you have questions about what to feed (or not feed) your child, consult your pediatrician, nutritionist or other health care practitioner.
For information about soy-based foods and soy allergy symptoms, read “Symptoms of a Soy Allergy & Sources of Soy” by clicking here.