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Soy: Miracle Food or Poison
A Soy Primer
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by Jan Erik Gjestvang-Lucky, Merchandiser
After having been a vegetarian for over fifteen years, I was surprised to learn that soy foods, which had become a staple in my diet, might be bad for my health. My first exposure to this idea was when our son was about two months old and very colicky. It was suggested that my wife stop eating soy because it could be passing through her breast milk and affecting our son. When it helped ease the symptoms of his colic, we pretty much eliminated soy from our diets. We did a bit of on-line research, and found some pretty alarming information on the possible negative health effects of soy. At the time, we didn’t look into it any further because getting through our son’s colic was a good enough reason to not eat soy foods for the time being.
We have recently started to pay more attention to this issue because we don’t want to needlessly limit our options for good, healthy sources of protein and other nutrients which many experts still believe soy to be. Soy supporters say it has been a healthy part of traditional diets in Asia for thousands of years, and modern research has uncovered an ever increasing list of health benefits to be gained from eating it. On the other hand, if eating soy foods will increase our risk of chronic and terminal disease, and even directly affect our son’s development, we obviously don’t want to expose ourselves to that. Opponents of soy say that although it was part of Asian diets, it was used as a seasoning or condiment, not as a main dish. They also say that the soy industry has taken a legume that was originally not even grown for food, but rather to enrich the soil, and, through deception, biased research, and lobbying of the FDA, made it out to be a wonder food. They claim that the industry and its “apologists,” motivated purely by profit and greed, are ignoring a growing body of research that shows soy foods to be toxic and dangerous.
To help make some sense of this, let’s compare claims from both sides, starting with those who say soy is bad for you.
Those who oppose the use of soy foods say that there are many problems with it that make it unfit for human consumption. Problems range from blocking mineral absorption to being hard to digest, from causing brain shrinkage and birth defects to multiple forms of cancer. Whole soybeans contain many natural toxins that inhibit growth and make it difficult for our bodies to absorb the nutrients in soy and other foods we eat. Enzyme inhibitors make it hard to digest the proteins in soy. These substances are also growth inhibitors, and, in animal studies, have interfered with normal growth and development. High levels of phytic acid in soy can also block the uptake of essential minerals like calcium, magnesium and zinc, which can lead to problematic mineral deficiencies. Because soy is so difficult for our bodies to digest and process, it was not originally grown for food. It was used in crop rotation and plowed under to enrich the soil. It wasn’t until soy fermentation was discovered that soy began to be used as food, as miso (aged, fermented soybean paste), tempeh (cake of cooked fermented soybeans), natto (boiled fermented soybeans), and shoyu and tamari (traditional aged soy sauces). Fermentation breaks down many of the anti-nutrients and makes soy easier to digest. Even in these forms, however, soy foods were never used as the mainstay of Asian diets, but rather in small amounts as flavorings.
The biggest concerns, though, seem to be about soy protein (isolated, concentrated, hydrolyzed, or texturized), and soy isoflavones. The soy proteins mentioned above are highly processed, as you may have guessed by their names, and this processing can remove healthy components of soy, and increase the concentration of unhealthy ones. This again blocks the absorption of essential nutrients. The processing often involves toxic chemicals, which can contaminate the finished product, and in some cases it can introduce high levels of aluminum, which has been linked to Alzheimer’s disease.
Soy isoflavones, otherwise known as soy phytoestrogens, are substances that mimic the effect of estrogen in the body. There are some studies that raise concerns about these isoflavones and their presence in diet food supplements and baby formula. They may lead to birth and developmental defects, or reproductive abnormalities later in life. They may also be linked to thyroid problems and increased rates of breast and other cancers in both men and women.
Soy opponents claim that the soy industry and its backers have known about these problems for a long time. Opponents claim backers have lied to the public in order to cover up these issues, first by claiming processing removed all of the problematic substances, then by changing their tune and claiming the substances, such as isoflavones, were not toxic but beneficial. Opponents say they have bullied the FDA and used biased research to support their claims, all with the ultimate goal of making more money with no regard for the human cost.
Not everyone agrees with these claims. The other end of the spectrum has supporters saying that soy can be a great source of cholesterol-free complete protein, as well as other vital nutrients, and (surprise, surprise) it may help reduce or eliminate symptoms of menopause, and even prevent osteoporosis, heart disease and various cancers.
Soy is thought to be a good food, at least in part, because it has been used for so long in Asian diets. Soybeans offer a complete protein, especially important for vegetarians, and soy, like all plant foods, has no cholesterol. In fact, studies have shown that soy can help reduce the risk of heart disease not only by reducing overall cholesterol, but also by improving the ratio of HDL (good) to LDL (bad) cholesterol. Soy is also rich in other minerals like calcium, zinc, magnesium, iron, and selenium.
Fermented soy foods, like tempeh and miso, contain probiotics, or “friendly” bacteria that live in our intestines and can help us gain and maintain health. Fermented soy also contains a growth medium for the probiotics that not only protects and feeds them, but also inhibits the growth of harmful bacteria and fungi. Probiotics are helpful because they enhance immune function, help elimination, provide B-vitamins, and may help control cancer and high cholesterol.
Many of the anti-soy claims seem to come from one particular source, an article on the negative effects of eating soy foods written by Sally Fallon, and Mary Enig, PhD. They have both written books on diet and nutrition, and are, respectively, the president and vice-president of the Weston A. Price Foundation. Both the article and the foundation have a pro-animal foods, anti-vegetarian bias, which is based on the nutrition research of its namesake, Dr. Weston A. Price. This article is titled “Tragedy and Hype” (http://www. westonaprice.org/soy/tragedy.html), and raises, in more detail, many of the concerns about soy listed above. There are two articles written in direct response to “Tragedy and Hype.” The first is “What About Soy?” (http://www.foodrevolution.org/what_about_soy.htm) by John Robbins, and the second is “Is It Safe to Eat Soy?” (http://www.veganoutreach.org/health/ soysafe.html) by Virginia Messina, MPH, RD, and Mark Messina, PhD. All three of them are vegetarians and have written books on vegetarian diet and nutrition, and Mark Messina is also a consultant for the soy industry, so they have a pretty obvious anti-meat, pro-vegetarian, if not outright pro-soy, bias. With that in mind, here are some of the rebuttals of claims made in “Tragedy and Hype.”
First of all, many of the studies that Fallon and Enig cite are animal studies, and though there is often a correlation between the effects of certain foods on animals and humans, just as often there is not, due to differences in biology, digestion, and metabolism. The risk of mineral deficiencies in vegetarians is, according to Robbins, overstated, because although phytates do act to block mineral uptake, the levels are “not high enough to cause mineral absorption problems for most people eating varied diets.” The Alzheimer’s/brain shrinkage claim is based on one study that many scientists think is inconclusive in determining the cause of these problems, especially since there are several studies that show soy may have a positive impact on cognitive function. The Messinas state that “there is no evidence that eating soyfoods regularly causes thyroid problems in those who eat a balanced diet.” The cancer claims are also inconclusive on both sides.
There do seem to be more studies showing potential cancer-reducing effects from soy than cancer-causing effects, but more research is needed to be sure.
Both Robbins and the Messinas do admit that there are potential problems with soy, especially in its highly processed, protein isolate forms. Why is isolated soy protein a concern? This quote from Soy Info Online explains it well: “positive health effects from ingesting plants are almost always due to a combination of the phytochemicals in those plants,” and “there are almost always major drawbacks to giving isolated phytochemicals to patients as opposed to the giving them the whole plant (or an extract of all of the phytochemicals).” This seems to be because the whole plant contains thousands of phytochemicals (“phyto”-plant) that work together to create a synergistic health benefit, as opposed to single phytochemicals working in isolation. Highly processed soy also tends to be genetically engineered, which, according to Monsanto’s research on its own genetically engineered soybeans, reduces the amounts of beneficial compounds and increases the levels of problematic ones.
Now that you have all of this conflicting information about soy, what do you do with it? How do you know what to believe, and what to do about soy in your diet? I’m sorry if I have muddied rather than cleared the waters, but I think that we can make our best choices when we have as much information available to us as possible. I highly recommend all three of the articles listed above, plus a fourth from Mothering magazine, “Whole Soy Story: The Dark Side of America’s Favorite Health Food” by Kaayla T. Daniel (http://www. mothering.com/articles/growing_child/ food/soy_story.htm). I also believe, as with most things in life, that the best path is the path of moderation, and one of the best authorities on your body is your body. Everybody’s body is different and responds to things differently. Learn to listen to yours, and it will tell you much of what you need to know. Good luck, and may you be happy and healthy!