By Aimee Raupp, author, licensed acupuncturist & herbalist, and women’s wellness & fertility expert
Last month I wrote a blog for the Mommybites website, entitled: Avoid Soy—for you and for baby. And, boy oh boy did it stir up some healthy debate. This month, I am following up that blog with more information on soy and why I advocate you avoid all processed soy foods (if you want to cook your own tofu and make your own soy milk following the traditional methods, I am all for it).
Notice I said the word “processed” before the word “soy” in my previous sentence. I want to define for you what the word processed means as I believe it will help you understand the soy debate. Processed foods—and, here I am talking about any processed food, not just processed soy food—are foods that have been altered from their natural state and are typically preserved with chemicals and full of synthetically derived ingredients.
Think: high fructose corn syrup or Yellow No. 5 food coloring.
Think: genetically modified foods and pretty much anything that comes in a package.
As I stated in my first book, “Food occurs naturally, in nature. Food grows on trees and in the dirt, comes from the sea or walks on legs. Food is not born in a laboratory in New Jersey.”
Now, I know you try your best to avoid feeding yourself and your family packaged processed foods but, I’d like to remind you that even foods claiming to be “healthy” can be processed too. And, soy is one of them.
Let me explain. Soy comes from soybeans, a legume native to East Asia. So, yes, it is a bean that grows in the dirt. However, soy based foods are manufactured and processed and are very far from their natural state (much the same as corn is a vegetable that grows in the dirt but high fructose corn syrup does not come from anywhere other than a laboratory).
At this point, I am sure you are wondering, “What about all those people in Asia eating soy?”
Soy based foods have been a part of Asian culture for approximately five thousand years. The big differences between the traditional soy foods they ate in Asia for thousands of years and the processed soy foods we eat here in the U.S. are (of course, I realize I am generalizing as some of you may only eat traditionally made soy foods):
- Soy foods were fermented. The process of fermentation partially digests foods so that we can easily digest and assimilate them. As well, the fermentation process neutralizes the natural toxins (like phytates and trypsin inhibitors) found in soy. And, an added bonus: fermented foods have natural probiotic activity and add a plethora of healthy bacteria to our digestive system. Fermented soy products like natto, tempeh and miso (as I mentioned in my first blog) are OK to eat in moderation.
- Soy foods were consumed in moderation. In the traditional Asian cultures soy products were served as a side dish—not a main one. According to articles published in both the Journal of Nutrition and Nutrition and Cancer, the amount of soy protein/day consumed in traditional Asian cultures was 1-7 grams of soy protein/day. The typical American can get in anywhere from 10-40grams of soy protein/day. That’s a big difference and is likely the reason soy is now a very common allergen. (FYI: 4 oz of tofu contains ~7grams of soy protein; 8 oz of soy milk contains ~12 grams of soy protein; 1 meal replacement bar (made with soy protein isolate) contains ~8-12 grams of soy protein)
- Soybeans were not genetically modified (GMO). Unfortunately, a large majority of the soybeans that are used to make soy food products come from genetically modified sources. Unless the package says non-GMO, the product is genetically modified. Interesting tidbit: In 1996, there were no acres of GM soybeans in the US. After just 13 years, virtually all US soybeans are considered genetically modified.
- Soy foods were slow cooked. Here’s the real clincher—the traditional act of making tofu (and soy milk) is a bit timely and involves quite a few steps, like: soaking dried soybeans for several hours, heating the liquid, mixing it with a “coagulant” and creating a curd/whey mixture. As I said, if you have the time, make tofu and soy milk the traditional way—I’m all for it (here’s a good link for making your own soy milk. However, slow cooking is not how the commercial store-bought soy products are made—unfortunately, it’s quite the opposite. Soy products on the market are processed at very high temperatures which denatures important enzymes that our body needs to digest soy. As well, processing soy creates toxins and carcinogens like nitrates and MSG that are extremely unhealthy for us to ingest. Genetically modified or not, organic or not—commercially made soy products are one of the most processed products on the market. Many argue this is another reason why soy is becoming one of the most common food allergies in the U.S.
Just to reiterate: Asian cultures traditionally ate slow cooked, non-genetically modified, fermented soy products as a side dish. Today’s soy is not slow cooked (instead it’s processed at high temperatures), often genetically modified, not usually fermented and consumed as a meal or protein substitute, not a side dish.
OK. Now, that I have laid out the differences between traditional soy foods and commercial soy foods, I want to discuss a very common soy substance found in nearly all packaged and processed foods (including infant soy formula): soy protein isolate.
Soy protein isolate does not occur naturally in nature and therefore, in my opinion, should be by no means considered a food. Soy protein isolate is the byproduct of processed soybean oil (also not a food). To make soy protein isolate, soybeans (which, again are typically genetically modified) are first de-hulled, then heated at very high temperatures and then crushed to extract soybean oil. The leftover soy pieces from the creation of soybean oil then undergo another extraction process that involves hexane — a known neurotoxin (note: organic soy protein isolates are not exposed to hexane). Next, these hexane treated soy pieces are soaked in a chemical mixture (which commonly contains ammonia and hydrochloric acid) to help concentrate protein levels and achieve a nice, soft texture. Finally, the mixture is then spray-dried. When this process is done—soy protein isolate contains a whopping 95% protein (in comparison to its mother, the soybean, which only contains about 20-35% protein).
My goal here is not to instill fear, it is just to educate and the above stated process sounds quite unnatural to me.
You see, the most common derivatives of the soybean, namely: soy oil, soy flour, textured soy protein, hydrolyzed soy protein and soy protein isolate all undergo extreme processing and are exposed to harsh chemicals and they are not food. Similar to high fructose corn syrup or egg white substitute or non-dairy creamers—these processed soy products are fake foods and should not be consumed.
Of course, my ‘argument’ against soy, thus far, has mainly been that the commercial store-bought soy products that most of you are consuming are processed, genetically modified, chemically manipulated and not food. And, I know some of the reader comments from my previous posts wanted me to back my statements up with more science… here, we go.
{Quick side note before I dive into the science—most of the studies involving soy (pro-soy and anti-soy) are considered “weak” in the scientific arena. This is mainly due to the fact that a lot of the studies are conducted on animals (rather than humans), are conducted using isolated soy derivatives (aka soy isoflavones or soy protein isolate) and not exclusively soy foods, were not conducted for a lengthy period of time and for the ones with human subjects the studies were not conducted on large populations. So—arguing for or against soy with hope of any hard science to back you up is near impossible. But, my take—being I was a research scientist at one point in my life—is that if there is science on the pro side and the con side: questions should be raised and more research needs to be done.}
- In 2005, researchers show that lab rats fed a diet “high in soybean products modulates anterior pituitary hormone production” and causes, “thyroid hypertrophy, reduce(d) serum thyroxine (T4) and tri-iodothyronine (T3), and markedly increase(d) serum thyroid stimulating hormone (TSH).” What that basically means is that a diet high in soybean products—particularly defatted soybean products (aka soy protein isolate) as these scientists studied—results in the thyroid gland enlargement and hypothyroidism. (J Mol Histol. 2005 May;36(4):265-74.)
- In 1994, The American Journal of Clinical Nutrition published a study that showed that after women ate sixty grams of soy protein (granted that’s a good amount of soy protein) per day for thirty days, their menstrual cycle changed, resulting in skipped ovulations and irregular menstruation for three months following the cessation of eating soy protein (Am J Clin Nutr. 1994 Sep;60(3):333-40).
- A 2011 study conducted on male rats found that there was a dose-dependent effect of soybean meal on circulating sex hormones. As the researchers stated, “The treatment significantly reduced the levels of testosterone and follicle stimulating hormone in the serum while it significantly increased the levels of estradiol, luteinizing hormone/interstitial cell stimulating hormone and prolactin. The results show that soybean had strong capability to disrupt hormonal functions. Hence, its indiscriminate use could increase the risk of infertility in males.” (Pak J Biol Sci. 2011 Jul 15;14(14):752-4.).
- A 1997, a study conducted on infants compared the overall soy isoflavone and phytoestrogen exposure from soy formula in comparison to both breast milk and milk formula. To quote the paper, “The daily exposure of infants to isoflavones in soy infant-formulas is 6-11 fold higher on a bodyweight basis than the dose that has hormonal effects in adults consuming soy foods. Circulating concentrations of isoflavones in the seven infants fed soy-based formula were 13000-22000 times higher than plasma estradiol concentrations in early life, and may be sufficient to exert biological effects, whereas the contribution of isoflavones from breast-milk and cow-milk is negligible.”( Lancet. 1997 Jul 5;350(9070):23-7.)
I think that’s enough scientific jargon to send your way. For more reading, I’d recommend this article from The American Nutrition Association: The Downside of Soybean Consumption. It contains a plethora of information and is well cited so you can do some more research on your own. And, for even more extensive reading check out the book that got me off of eating soy, The Whole Soy Story by Kaayla Daniels.
I hope you find this article more informative and substantiated than my first post on soy. The main points I want to drive home are:
- Avoid processed soy derivatives (soy oil, soy flour, soy protein isolate, textured soy protein and hydrolyzed soy protein) as they are not food.
- If you want to continue drinking soy milk and eating tofu—make it yourself (from organic, non-GMO soybeans)
- When buying commercial soy products, be sure they are fermented.
The science I presented has been published by esteemed medical journals and should be taken into account when making your decision about eating soy or not. However, as I stated above—hard science for or against soy is missing in the medical literature.
If after reading this article and you still disagree with me on the soy topic—please, oh please read your labels and avoid any processed food “stuffs”. If we focus on eating real food—the kind that doesn’t come with a label on it—that is wholesome, organic and nutrient dense our health will flourish.
And, last but not least—everything in moderation. If once in a while you or your child has something with soy in it, it’s not going to be the end of the world. Just, do the best you can do for you and your family and always be easy on yourself.