The Truth Behind Major Myths About Soy

Tempeh sliced on a boardMisinformation about the so-called dangers of soy abound. Ironically, the fact that soy is an exceptionally nutrient-dense food has helped to fuel some of the myths about its effects on human health. The soybean contains a long list of macro- and micronutrients, including…

  • Calcium
  • Iron
  • Fiber
  • Magnesium
  • Manganese
  • Phosphorous
  • Vitamins B1, B2, B3, B5, B6 and B9
  • Vitamin C
  • Zinc
  • Omega-3 and -6 fatty acids
  • Phytoestrogens

Much of the controversy over soy centers on the last item on that list, phytoestrogens. 

Phytoestrogens: Separating Truth from Speculation

Phytoestrogens are compounds that occur naturally in plants and are structurally similar to the hormone estrogen. Soy contains isoflavones, a type of phytoestrogen. Because these compounds are structurally similar to estrogen, and high levels of estrogen in the body have been linked to the development of certain kinds of cancers, some claim that eating soy can cause cancer.

This is demonstrably false. “The metabolism and functionality of phytoestrogens are incredibly complex, and vary between individuals,” explained Dr. Holly Wilson, who describes herself as an outspoken advocate for a plant-based lifestyle, in an article for Free From Harm. Although the effects are complex, the consensus among scientists is that “isoflavones do not have the estrogenic effect of inducing tumor growth,” Wilson stated. In fact, scientific evidence indicated that isoflavones can protect against hormone-dependent cancers – the same type they are falsely claimed to cause!

Large clinical trials have shown that soy consumption actually lowers a person’s risk of developing breast cancer. It appears that isoflavone have anti-estrogen properties that prevent estrogen hormones from encouraging tumor growth. Epidemiological data drawn from comparisons of countries where soy is a dietary staple and those where it is not indicate that soy may also help to prevent…

  • Coronary artery disease
  • Hypertension
  • Ischemicstroke
  • Osteoporosis
  • Hip fracture
  • Diabetes
  • Obesity

Rates of all these conditions are significantly lower in countries whose populations eat more soy.

Who’s Churning Out Misinformation About Soy?

The majority of the fear-mongering surrounding soy can be traced back to the Weston A. Price Foundation (WAPF). The WAPF lobbies for the interests of animal farming operations, particularly those dealing in raw milk and grass-fed beef. To promote those interests, the WAPF does everything in its power to discredit the benefits of plant-edamame in a bowlbased eating. The WAPF sees soys as an especially threatening competitor –and for good reason. Soy sales have risen from $500 million in 1992 to 5.2 billion  in 2011! No wonder the WAPF is working so hard to convince consumers that eating soy will destroy their health.

If you check the sources of articles on the supposed dangers of eating soy, many of them link back to the WAPF. These articles may even cite clinical and medical journals in an attempt to appear credible, but doctors who’ve evaluated the claims say that the WAPF picks through the findings, selectively highlighting those that support its agenda.

How to Pick the Healthiest Soy Foods

Another pervasive myth about soy is that only healthy soy foods are fermented soy foods. The eating habits of Asian cultures, the source of much of what we know about soy’s beneficial effects on human health, thoroughly disprove this idea. Research conducted by Ginny Messina, R.D., shows that soy consumption in Japan is split almost equally between fermented foods like miso and natto and unfermented foods like tofu and soybeans. In Shanghai, Messina found that most of the soy in peoples’ diets came from two unfermented soy foods – tofu and soymilk.

What really matters is not whether soy has been fermented, but whether it has been overly processed. As with any food you eat, whole soy foods are the healthiest option. Avoid  soy foods with labels that list “soy protein concentrate”…“soy isolate”…and “isolated soy protein.”

 To reap the health benefits of soy, your best options include:

  • edamame (whole soy beans)
  • Soy milk
  • Tofu
  • Tempeh
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