Boy Oh Boy is Soy Safe?
Is soy consumption safe for babies? Will eating soy foods cause breast cancer? Can boys and men eat soy? What are the health benefits of soy? Who opposes soy and why? The great debate continues. What is soy and why the controversy?
Before we begin to look at the research on soy; let’s discuss what soy is and where it comes from. Soy is a subtropical plant, native to southeastern Asia. Soy is a member of the pea family and grows in pods. Soy has been a trusted, safe, dietary staple in Asia for more than 5,000 years. Soy is a ‘nutritionally complete’ protein meaning that it contains all of the essential amino acids required for optimum health. Soybeans contain thousands of beneficial phytochemicals including iron, ALA omega-3 fatty acids, fiber and like all plant-foods, soy is cholesterol-free.
You may recognize a popular soy product: tofu. Tofu is made in much the same way as cheese, except that it is made from soybeans rather than milk. It is entirely plant-based, which means that it is an ideal food for vegans and for people who are intolerant of dairy products. Tofu was invented in China about 2,000 years ago and has been part of the Chinese and Japanese diets for a very long time. I love cooking with tofu; it takes on the flavor of whatever you are cooking. You can use firm tofu for heartier dishes and may use the softer tofu blended for creamy dressings and/or sauces.
Another favorite, healthy soy product is edamame, which resembles peas in a pod as mentioned earlier. Edamame can be eaten slightly steamed or raw and is an excellent source of protein and fiber. It makes a healthy snack and is a great treat for athletes. Tempeh, which is fermented soy, has been around in Indonesia for more than 2,000 years. Tempeh gains some digestive benefits from the enzymes formed during the fermentation process.
So now that we have the basics of soy, let’s discuss the safety and health benefits of soy. Soy has been shown to be safe for babies, boys and men, and for women including those with breast cancer.
Soy and Breast Cancer: Many falsely believe that high levels of isoflavones, active ingredients in soy that behave like estrogen in the body, may increase the risk of breast cancer. While high levels of isolated isoflavones may do so, it appears that the total mix of weak plant estrogens in soy protects the body’s estrogen receptors. This protection may reduce the effects of excess estrogen exposure from such external sources as meats and dairy products from hormone-treated cows as well as artificial chemicals and industrial pollutants that act as foreign estrogens. (Weil) According to the American Cancer Society, soy may reduce the risk of certain cancers: “As with other beans or legumes, soy and foods derived from soy are an excellent source of protein and thus provide a good alternative to meat. Soy contains several phytochemicals, and is a rich source of isoflavone phytochemicals, which have weak estrogenic activity and may protect against hormone-dependent cancers. There is growing evidence from epidemiologic studies that the consumption of traditional soy foods such as tofu may decrease the risk of cancers of the breast, prostate, or endometrium, and there is selected evidence for a risk reduction of some other cancers.” (Kushi, Doyle, McCullough, and et al 30-67)
Critics of soy say that there is estrogen in soy which is not true; there is no estrogen in soy! Estrogen comes from meat and dairy sources and also some environmental toxins that mimic estrogen. The term “phytoestogen” confuses people. A more accurate term may be “estrogen-like phytoadaptogen”. Unlike estrogens, adaptogens will enhance or suppress activity depending on the physiological needs of the tissue. This response is discussed in the literature as selective estrogen response modifiers (SERMs). (Raneri) Most notable SERMs include the toxic drug Tamoxifen for breast cancer reduction, which I totally oppose. Tamoxifen has horrible side effects and the main goal is to reduce the estrogen floating around in the body. Would it not be more prudent to ‘shut off’ the estrogen source in the first place (i.e. stop eating meat and consuming dairy)?
And yet another study published in the British Journal Cancer says “…epidemiological evidence suggests soy intake is associated with decreased breast cancer risk: A recent meta-analysis found that in Asian populations, higher soy intake was associated with a 29% decreased risk of breast cancer. However, evidence suggests that this benefit depends on soy consumption early in life.” (Wu, Yu, Tseng, and Pike 9-14)
Speaking of soy consumption early in life: Soy infant formula has been commercially available since the 1960s. Estimates are that more than 20 million American adults received soy
infant formula at some point during their infancy. Current data indicate that about 10 to 15 percent of the dollars spent on infant formula are from the purchase of soy infant formula. This formula has been shown to promote normal growth and development. (Badger, et al 1668s-72s)
A recent evaluation by the National Institute of Environmental Health Sciences (NIEHS) and the American Academy of Pediatrics (AAP) support the use of soy infant formula. The AAP position is that there is “no conclusive evidence from animal, adult human or infant populations that dietary soy isoflavones may adversely affect human development, reproduction, or endocrine function.” (Bhatia, Greer, and the Committee on Nutrition 1062-1068) Soy protein is easily digested and the formula itself is lactose-free and fortified with more than 25 nutrients, including calcium, Vitamin D and essential fatty acids. Most infants allergic to cow’s milk formula will not have difficulty with soy formula. However, I do recommend that infant formula from soy comes from organic, non-GMO sources to reduce any possible allergies to soy. Note that soymilk should not be used as a substitute for soy infant formula.
Soy and boys and men: Dr. Mark Messina who is a nutrition expert, former director with the National Cancer Institute, and adjunct associate professor at Loma Linda University provides research on his website: “A wealth of clinical data (>30 studies) show that an intake of between 50 and 150 mg per day of isoflavones from soy foods or supplements doesn’t lower testosterone levels. Furthermore, the evidence shows that similar amounts of isoflavones do not affect estrogen levels in men.” (Messina) While much soy research has focused on benefits for women, soy can also play an important role in the diet for men. Some men may be reluctant to consume soy because of a mistaken belief that soy causes feminizing effects, a belief that is without scientific support. “In fact research suggests that soy consumption is associated with a decreased risk of prostate cancer, and soy also has heart health benefits including lowering cholesterol. Since many soy foods provide high-quality protein and are low in saturated fat, they are excellent choices for men looking to increase the amount of protein in their diets.” (Yan, and Spitznagel 1155-63)
I’ve been recommending soy foods for years. I will, however state that while I feel some soy products are safe (tofu, edamame, tempeh, and miso), I do recommend consuming only non-GMO (non-genetically modified, organic) soy and soy products. There are many reasons for this recommendation as genetically modified soy may cause allergies and, or digestive problems. As I also recommend a more plant-based diet, I would suggest using soy “transition” foods such as soy burgers, soy hot dogs, soy crumbles and such in limited quantities and not every day. Many of these products contain questionable ingredients, but they do make a healthier substitution when trying to avoid animal products. We know that animal products including meats, dairy, eggs, and fish contain cholesterol, artery-clogging fat and many disruptive hormones. Soy foods do not contain cholesterol nor the artery-clogging fat and toxic ingredients found in animal flesh.
And speaking of animal flesh…so who are the anti-soy critics? Many groups have ties to the meat and dairy industry and/or farming groups, so you can see why they do not want Americans to consume the more heart-healthy, cancer-reducing soy. They promote eating their heart-attack-and-cancer-causing meat and dairy products. A few years ago, I had heard of a dairy group who actually tried to sue some soy milk companies for using the word ‘milk’ on their labels. As if the dairy board can claim exclusivity on the term ‘milk’!
A well-noted anti-soy group is Weston Price. It appears they have ties to the dairy associations and as Dr. David Dalman states, …“have misrepresented most of their studies.” A good ‘conversation’ to follow can be found on Dr. David Dahlman’s website (in Works Cited). Dr. Dahlman has cited all their flaws and has addressed the Weston Price claims about soy being unhealthy for human consumption. He takes each claim and counteracts with real research. Dr. Dahlman says… “Follow the money!” He adds, “The most commonly quoted studies seem to be interpreted simply to advance the argument rather than to understand it. Reading the titles or only the discussion portion of the studies by the soy critics ignore the internal design of the study and have lead to wrong conclusions. Common sense will find that one thing is certain. Rarely will you find billions of people embracing a food for centuries only to find they have been wrong.” (Dahlman)
Weil, Andrew. “Rethinking Soy?” Ask Dr. Weil. Dr. Andrew Weil, 12 Mar 2004. Web. 1 May. 2012. <http://www.drweil.com/drw/u/id/QAA326575>.
Kushi, LH, C Doyle, M McCullough, et al. “American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Reduction.” Cancer Journ Clin. 62. (2012): 30-67. Print.
Katy Raneri. “Does Soy Increase The Risk of Breast Cancer?” Soy Nutrition: Our Experts. Soy Nutrition, 05 Oct 2011. Web. 1 May. 2012. <http://www.soynutrition.com/ourexperts/ourexperts-answered-questions/does-soy-increase-the-risk-of-breast-cancer/>.
Wu, AH, MC Yu, CC Tseng, and MC Pike. “Epidemiology of Soy Exposures and Breast Cancer Risk.” British Journal Cancer. 98. (2008): 9-14. Print.
Badger, T, et al. “The Health Implications of Soy Infant Formula.” Am J Clin Nutr. 89.(suppl) (2009): 1668s-72s. Print.
Bhatia, J, F Greer, and the Committee on Nutrition. “Use of Soy Protein-Based Formulas in Infant Feeding.” Pediatrics. 121. (2008): 1062-1068. Print.
Messina, Mark. “Is It Possible That Soy Could Have a Negative Effect on Men?” Ask Our Experts. Soy Nutrition, 29 Sep 2011. Web. 1 May. 2012. <http://www.soynutrition.com/ourexperts>
Yan, L, and EL Spitznagel. “Soy Consumption and Prostate Cancer Risk in Men: A Revisit of the Meta-analysis.” AM J Clin Nut. 89. (2009): 1155-63. Print.
Hwang, YM , et al. “Soy Food Consumption and Risk of Prostate Cancer: A Meta-analysis of Observational Studies.” Nutr Cancer. 61. (2009): 598-606. Print.
(submitted ENG JTCC May 2012; TH)