The Hazards of Soy

For years I have purchased soy milk, stocked it on my shelf, told myself I should open it and include it into my diet. After opening it though, it just sits in the refrigerator for a month or two. Then, of course, it’s too old to drink, so I throw it down the sink and the cycle repeats itself a couple months later. Now I believe that my body was telling me that it didn’t want the soy milk as I’ve been reading up on the soy controversy lately. Here is a summary of that information. . .

Those magical isoflavones—the estrogen-like hormones that all work to help you stay young and healthy may not be the magical food that you have been led to believe. Soy is just one example of the many fad foods/ supplements/ cures that I find myself exposed to in trying to decipher the long-term health benefits before sharing them with my clients.

Soy has been marketed as a health food when, at one time, it was only a toxic by-product of the vegetable oil industry. Hmm. . . .that doesn’t sound right, does it? Don’t we eat soy in lots of things now?

Advances in technology make it possible to produce Soy Protein Isolate (SPI) from what was once considered a waste product—defatted, high-protein soy chips—transforming something that looks and smells terrible into products that can be consumed by human beings. Flavorings, preservatives, sweeteners, emulsifiers and synthetic nutrients have turned SPI, the food processors’ nightmare into a very lucrative business.

All soybean producers pay a mandatory assessment of one-half to one per cent of the net market price of soybeans. The total—something like $80 million annually—supports United Soybean’s program (https://www.ams.usda.gov/lsg/mpb/rp-soy.htm) to “strengthen the position of soybeans in the marketplace and maintain and expand domestic and foreign markets for soybeans and soybean products.”

Soy milk, made from raw soy, has posted the biggest gains, soaring from $2 million in 1980 to $300 million in the United States last year. Recent advances in processing have transformed the gray, thin, bitter, beany-tasting beverage into a product that Western consumers will accept.

The first soy foods were fermented products like tempeh, natto, miso and soy sauce. At a later date, possibly in the 2nd century BC, Chinese scientists discovered that a purée of cooked soybeans could be precipitated with calcium sulfate or magnesium sulfate (Plaster of Paris or Epsom salts) to make a smooth, pale curd they called tofu or bean curd.

The Chinese never ate unfermented soybeans as they did other legumes such as lentils, because the soybean contains large quantities of natural toxins or “antinutrients.” These antinutrients are not completely deactivated during ordinary cooking. They can produce serious gastric distress, reduced protein digestion and chronic deficiencies in amino acid uptake. In test animals, diets high in these antinutrients called trypsin inhibitors cause enlargement and pathological conditions of the pancreas, including cancer.

Other harmful substances in soy products include haemagglutinin, goitrogens, phytic acid, nitrates, and phytoestrogens (in large amounts.) What are these things? Well. . .

Haemagglutinin is a clot-promoting substance that causes red blood cells to clump together.

Trypsin inhibitors and haemagglutinin are growth inhibitors that are deactivated during the process of fermentation. In precipitated products (like tofu,) enzyme inhibitors concentrate in the soaking liquid rather than in the curd. Thus, in tofu and bean curd, growth depressants are reduced in quantity but not completely eliminated.

Soy also contains goitrogens – substances that depress thyroid function. This is a major concern of mine as I see our population having more and more thyroid issues with each passing year.

Soybeans are also high in phytic acid, present in the bran or hulls of all seeds. Phytic acid can block the uptake of essential minerals—calcium, magnesium, copper, iron and especially zinc—in the intestinal tract. Scientists are in general agreement that grain and legume-based diets high in phytates contribute to widespread mineral deficiencies in third world countries.

The Japanese have traditionally eaten small amounts of tofu or miso as part of a mineral-rich fish broth, followed by a serving of meat or fish. This is not how vegetarians and vegans consume soy. The results of calcium, magnesium and iron deficiency are well known; those of zinc are less so. These are the exact mineral deficiencies I have been seeing in my practice.

Many people in my practice now come in with that tell-tale tan chin, indicative of iron deficiency. They are low in energy and worried about osteoporosis, but they look like thyroid cases.  Their thumbs point toward their hips as they stand and walk instead of pointing forward, and they carry more weight evenly dispersed on their body. Most of my clients are also low in zinc.

Zinc is needed for optimal development and functioning of the brain and nervous system, it is used in protein synthesis, collagen formation, in the blood-sugar control mechanism thus protecting against diabetes, and is needed for a healthy reproductive system. Zinc is a key component in numerous vital enzymes and plays a role in healthy immune system function These uses are among hundreds of other ways zinc is used by the body.

Soy processors have worked hard to get these antinutrients out of the finished product, particularly soy protein isolate (SPI), the key ingredient in most soy foods that imitate meat and dairy products, including baby formulas and some brands of soy milk. (For more information on that, read my other article on soy, The Hazards of Feeding Soy to Children: /Diet_Nutrition/FeedingSoyToChildren.html.)

Nitrites, which are potent carcinogens, are formed during the spray-drying process of making Soy Protein Isolate (SPI). Test animals fed SPI develop enlarged organs, particularly the pancreas and thyroid gland, and increased deposition of fatty acids in the liver.

If this is so, then why are SPI and textured vegetable protein used extensively in school lunch programs, commercial baked goods, diet beverages and fast food products? (Yikes!) Soy is also heavily promoted in third world countries and forms the basis of many food giveaway programs.

Researchers studying soy-based foods in one school research project noted several alarming symptoms after children ate soy-based meals including: “occasional” vomiting, periods of moderate diarrhea, upper respiratory infections, rashes and fever.

Many ask then, why do the Japanese have less cancer than Americans? Do they? I’ve heard over the years that the Japanese, who allegedly eat 30 times as much soy as North Americans, have a lower incidence of cancers of the breast, uterus and prostate. BUT the Japanese, and Asians in general, have much higher rates of other types of cancer; particularly cancer of the esophagus, stomach, pancreas, thyroid and liver.

Just how much soy do Asians really eat? A Cornell study conducted by Colin T. Campbell in 1998 found that the average daily amount of soy protein consumed in Japan was about eight grams for men, and seven for women. This is only less than two teaspoons. Do Japanese really eat more soy than Americans? At this point, I don’t think so.

Except in times of famine, Asians consume soy products only in small amounts, as condiments—not as a replacement for animal foods—with one exception. Celibate monks living in monasteries and leading a vegetarian lifestyle find soy foods quite helpful—because they dampen libido.

So what are the side-effects of too much soy? (These are only in alphabetical order and not by the proportion of incidence.)

  • Bloating
  • Breast cancer (Soy isoflavones mimic estrogen)
  • Calcium deficiencies (soy blocks calcium absorption)
  • Cognitive decline (esp. in post-menopausal women that have increased levels of estrogen in their blood)
  • Constipation
  • Depression
  • Endocrine disruption
  • Fatigue
  • Goiter
  • Hair loss
  • Hot flashes
  • Hypothyroidism
  • Infertility
  • Irregular periods
  • Lethargy
  • Loss of muscle tone
  • Painful periods
  • Premature aging
  • Thyroid cancer
  • Thyroid disease
  • Thyroid Stimulating Hormone increase
  • Uterine cysts
  • Vitamin D deficiencies
  • Weight gain despite workouts and dieting

In 1991, Japanese researchers reported that consumption of as little as 30 grams or two tablespoons of soybeans per day for only one month resulted in a significant increase in thyroid-stimulating hormone, and 100 grams of soy protein, (promoted for its bone-building isoflavones and cholesterol-lowering effects) contains the estrogenic equivalent of the Pill. In vitro studies suggest that isoflavones inhibit synthesis of estradiol and other steroid hormones. I wonder if it’s really safe to take this kind of supplement if you have a family history of estrogen-influenced breast cancer. I don’t think I’d chance it. We get enough xenoestrogens in our environment as it is.

Some Helpful References: