the soybean saga: myths and facts
Soy gets such mixed reviews, it’s difficult to decipher fact from fiction. Portrayed as everything from a wonder food to the scourge of health, the soybean has become one of the most controversial edibles on the planet.
Soy as a superfood
Glycine max has played a major role on the food scene for over 3,000 years and now comprises one of the world’s largest crops. Consumed whole (edamame) and in soy milk and tofu, food additives and emulsifiers, vitamin supplements, medicines, and as soymeal in animal feed, the versatile bean provides a rich source of:
- All of the essential amino acids
- Micronutrients: calcium, iron, magnesium, manganese, phosphorus, potassium, zinc, B vitamins, and vitamin C
- Omega-3 and -6 fatty acids
Soy milk contains about as much protein as cow’s milk (but with 60% less saturated fat), high calcium, and three times more magnesium than dairy milk, all vital to bone health. Daidzein, an isoflavone found in soy, is used in the drug ipriflavone to treat osteoporosis. Plus, soy is cholesterol-free and can reduce LDL (bad) cholesterol.
Soy’s bad reputation
It started years ago with reports by The Weston A. Price Foundation (WAPF), a lobbyist for the animal-farming industry, promoting animal-based foods over plant-based and launching the Soy Alert! campaign. The WAPF claims saturated animal fat is essential for good health and that this fat and high cholesterol have no link to cardiovascular disease and cancer, and that meat-eaters live longer than vegetarians. Dr. Justine Butler, a health campaigner for Viva!Health, warns that the WAPF cites scientifically flawed studies, duping consumers into seeing soy as “some sort of dietary pariah.”
A few soy myths and facts:
1. “It’s a GM crop.”
Currently, 81% of the global soybean crop is genetically modified (GM), with about 85% of that used for livestock feed. In Free from Harm, Holly Wilson, MD, says “the GMO soy consumed by farmed animals is utilized as a source of protein by them, and does not just magically evaporate in the slaughterhouse or the milk processing plant. It ends up on your plate.” That’s why we should purchase products labeled “non-GMO”!
2. “Contains estrogen.”
Wrong! Soy contains phytoestrogens found in plants, not estrogen found in humans. Actually, phytoestrogens in the human body can lower the risk of cancer by blocking estrogen (Messina M, Barnes S. The role of soy products in reducing risk of cancer. J Natl Cancer Inst. 1991; 83:541-546). In addition, isoflavones (phytoestrogen compounds in soy) are powerful antioxidants known to protect against cancer.
3. “Causes cancer.”
Again, the blame’s pinned on phytoestrogen mistaken as estrogen. Wilson says, “Isoflavones [in soy] have demonstrated a protective benefit against hormone-dependent cancers.” And Marji McCullough, ScD, RD, strategic director of nutritional epidemiology for the American Cancer Society, reports moderate consumption of soy foods appears safe for breast cancer survivors and may even lower breast cancer risk. Yet the estrogen in cow’s milk is thought to promote cancer growth.
4. “Feminizes men.”
Thinking soy causes gynecomastia (enlarged breasts) comes from more confusion around estrogen and phytoestrogen. A 2010 review in Fertility and Sterility concluded that isoflavone-rich soy and supplements don’t affect men’s testosterone levels nor, according to nine studies, estrogen levels. The Estrogen Dominance Guide, on the other hand, reports cow’s milk can constitute 80% of our dietary intake of estrogen and that cows are given hormones to increase their growth and milk production, which can contribute to gynecomastia.
4. “Disrupts growth and reproductive development.”
While the WAPF campaigns against giving infants soy-based formula, Victoria J. Drake, PhD, of the Linus Pauling Institute at Oregon State University, says the latest research shows infants on soy-based formula are at no greater health risk than those on dairy formula.
5. “Hurts the environment.”
Soy plantations are blamed for their impact on the Amazonian rain forest. Butler reminds us, though, that the problem’s more about animals eating soy than it is people, stating “80% of the world's soya production is fed to livestock so that people can eat meat and dairy foods.”* * *So, is soy safe? Aside from processed soy and soy supplements requiring more study, soy appears safe and nutritious (especially in its more natural and non-GMO states). We’ll just have to weigh the facts and judge for ourselves.
Sources:“The Truth about Soy—Busting the Myths,” Rise of the Vegan
Holly Wilson, MD, “A Vegan Doctor Addresses Soy Myths and Misinformation,” Free from Harm
Judith C. Thalheimer, RD, LDN, “The Top 5 Soy Myths,” Today’s Dietitian
Justine Butler, “Ignore the Anti-Soya Scaremongers,” The Guardian
Sarah Klein, “5 Myths about Soy You Probably Still Believe, “ The Huffington Post