To Soy or Not to Soy, That is the Question.
I jumped on the soy bandwagon over 10 years ago. After all, in 1999 the FDA approved labeling which stated, “Diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease.” Besides promoting heart health, the industry says, soy can alleviate symptoms associated with menopause, reduce the risk of certain cancers and lower levels of LDL, the “bad” cholesterol. Soy ingredients weren’t only safe — they were beneficial – I was sold!
Touted as the new miracle health food, I began adding soy in large amounts to my diet. So instead of regular milk, I bought soy. I used soy protein powder in my smoothies, enjoyed soy ice cream, carried soy protein bars and roasted edamame in my purse and made tofu stirfries for dinner. Several years ago I began really questioning everything I put in my mouth. I have become to view food as medicine. So, I wondered whether my “healthy” soy habit was really benefiting my PCOS?
Once I started to investigate, I found that The Journal of the American Medical Association had reported that isoflavones do not improve cholesterol levels, cognitive function or bone mineral density. The American Heart Association backtracked on its earlier support of soy, and is now saying that there is no evidence that soy has specific benefits for heart health or for lowering cholesterol. Research on the use of soy and isoflavones for cancer prevention is also inconclusive.
When you start to investigate the benefits and risks of soy – it really is a mixed bag. Here are my concerns.
Soy is a GMO Crop
The first thing that I uncovered is that the vast majority of soy at your local market is not a health food. Soybeans are one of the “biotech food” crops that have been genetically modified (GMO). These soybeans are being used in an increasing number of products. In 1995, Monsanto Company introduced Roundup Ready soybeans that have been genetically modified to be resistant to Monsanto’s herbicide Roundup through substitution of the Agrobacterium sp. (strain CP4) gene EPSP (5-enolpyruvyl shikimic acid-3-phosphate) synthase. I don’t know about you but it sounds like Franken-food to me! (1) The plants also contain genes from bacteria that produce a protein that has never been part of the human food supply.
In 1997, about 8% of all soybeans cultivated for the commercial market in the United States were genetically modified. In 2010, the figure was 93%.(2) In North America, all soy that is labeled “organic soy” is guaranteed to not be genetically-manipulated and not be treated with herbicides. So eating organic soy does avoid the GMO issue.
Russian biologist Alexey V. Surov, and his colleagues set out to discover if Monsanto’s GMO soy, leads to problems in growth or reproduction. After feeding hamsters for two years over three generations, those on the GMO diet, and especially the group on the maximum GM) soy diet, showed devastating results. By the third generation, most GMO soy-fed hamsters lost the ability to have babies. They also suffered slower growth, and a high mortality rate among the pups. In addition to the GMOs, Surov acknowledged that, it could be contaminants, or higher herbicide residues, such as Roundup. (3) Without detailed tests, no one can pinpoint exactly what is causing the reproductive issues in these Russian hamsters. I just know if I am going to avoid GMO foods including GMO soy to safeguard my health and the health of my family. Look for organic soy products that say “nonGMO”
Soy is Processed with Hexane
The bulk of the soybean crop is grown for oil production which leads to the 2nd problem with soy. I recently wrote a post about salad dressing and avoiding soybean oil due to high Omega 6 fatty acids. However here is another reason to avoid soybean oil. Soybean seed contains about 19% oil. To extract soybean oil from seed, the soybeans are cracked, adjusted for moisture content, rolled into flakes and solvent-extracted with commercial hexane. Hexane is an EPA-labeled air pollutant and neurotoxin, which helps to separate the oil from the protein. The oil then goes through a process of cleaning, bleaching, degumming and deodorizing to remove the solvent and the oil’s characteristic “off” smells and flavors. The lecithin that forms a heavy sludge in the oil during storage used to be regarded as a waste product, but now it has been turned into a valuable market in its own right as an emulsifier. (3) The effects on consumers of hexane residues in soy foods have not yet been thoroughly studied and are not regulated by the FDA. Not all soy products contain hexane, however. Look for the label that says “made with organic soy.”
Soy is a Common Allergen
Soy also is one of the foods — in addition to wheat, corn, eggs, milk, nuts, and shellfish — most likely to cause allergic reactions. Most people equate food allergies with anaphylaxis, or a severe emergency immune response, but it is possible to have a subclinical sensitivity, which can lead to health problems over time. Non-fermented soy products also contain a number of potentially health-disrupting “anti-nutrients”, such as phytic acid, the fermentation process drastically decreases the levels of these components. After a long fermentation process, the phytate and “anti-nutrient” levels of soybeans are reduced, and their beneficial properties become available to your digestive system. Eating fermented soy is far more beneficial.
Phytoestrogens in Soy
Soybeans are a major dietary source of the isoflavones - genistein and daidzein. Both are phytoestrogens, plant molecules that are structurally and functionally similar to mammalian estrogens. Phytoestrogens in soy are not true hormones, rather they are similar structurally so they act like hormones and can cause endocrine disruption. They can bind with hormone receptors and can interfere with the production of hormones. They are 1200x less potent than human estrogens. But if you are eating large quantities of soy it can become a problem. Soy phytoestrogens are not weak. Drinking even two glasses of soymilk daily for one month provides enough of these compounds to alter your menstrual cycle. Although the FDA regulates estrogen-containing products, no warnings exist on soy.
Those women with PCOS who are trying to conceive will be interested in this study. According to a study involving humans, the soy isoflavone genistein has been found to impair sperm as they swim toward the egg. (5) Even tiny doses of the compound in the female tract could destroy sperm. What’s more, researchers explain avoiding soy around a woman’s more fertile days of the month might actually aid conception. Moreover, what was surprising and telling about soy’s harmful effects on human health was that it took smaller doses of genistein to create infertility problems in human females than in mice.
Studies have shown isoflavones like genistein are among the nutrients whose bioavailability actually increases when the soy food they come from is fermented. So if you ferment a soy product, the genistein becomes more readily absorbed. (6)
Soy Can Harm Your Thyroid
Goitrogens are substances that block the synthesis of thyroid hormones and interfere with iodine metabolism, thereby interfering with your thyroid function. Phytic acid in soy has the ability to bind to minerals, proteins and starch, and results in lower absorption of these substances. Hence, phytic acid, in large amounts, can block the uptake of essential minerals, like calcium, magnesium, copper, iron, and especially zinc in the intestinal tract. Soy also inhibits the uptake of one of the most important minerals needed for growth and metabolism, iodine, which is used by the thyroid gland in the production of thyroid hormones. On a side note I think it is interesting that Oprah’s Doctor and GYN guru Dr. Christine Northrup (I think she is great BTW) recommends soy and has recently disclosed that she is hypothyroid. Oprah touted the benefits of soy on her show (that was one of the reason’s I jumped on the bandwagon) also has thyroid issues.
What About the Benefits?