July 26, 2012


Articles by Dr. Erdman are for informational purposes, and are not to be taken as specific medical advice.

How many of you think that soy is a healthy protein source that can be substituted for some meats in your diet? We’ve been told that you need to reduce saturated meat fats and eat more ‘vegetarian.’ This is how most ‘health’ providers will council you when it comes to heart health, cancer prevention and good nutrition. What does good research say?

Research done by commercial soy producer’s claim that Asians have a diet high in soy and yet they have lower rates of breast, prostate and colon cancers.  Asians have been found to eat, on average about 10 grams, or fewer than 2 teaspoons, of soy per day. About 1.5% of their calories are from soy. Compare that to the 100 grams of soy protein recommended by Protein Technologies International to supposedly reduce cholesterol levels. That’s ten times what the Asians consume. In 1992, the Swiss Health Service estimated that 100 grams of soy protein provided estrogen equivalent to the pill.

They also forgot to tell you that Asians have higher rates of esophagus, stomach, thyroid, pancreas and liver cancers. To apply their logic, soy must also cause those cancers to be more prevalent, right? The fact that 85% of consumers perceive soy products as healthful, and 84% agree with the FDA’s claim that consuming 25 grams of soy daily reduces your risk of heart disease, just shows you how pervasive the notion has become. Marketing folks, marketing.

Here’s why soy is on my list of foods to avoid. One, it contains antinutritional factors such as soyatoxin, phytates, goitrogens and estrogens. Some interfere with enzymes needed to digest protein. Small amounts may be fine, but not in the quantities most Americans are getting in their diet. The second is that soy contains hemagglutinin, which is a clot promoting substance that causes your red blood cells to clump together . Not a good thing! Thirdly, it contains goitrogens, which block the synthesis of thyroid hormones and interfere with iodine metabolism. Fourthly, it contains phytates. Phytic acid binds to metal ions, preventing proper absorption of certain minerals like calcium, magnesium, iron and zinc. Do you need those minerals? Fifth, soy has isoflavones, a type of phytoestrogen, which is a plant compound resembling estrogen. Soy blocks estrogen use, which leads to disrupted endocrine function, and may cause infertility and promote breast cancer in women. How often do you see boys and men with ‘man-boobs’?  Too much soy, anyone?

The last, and worst, use of soy is in infant formulas. 20% of infants in the US are now fed soy. The estrogens in soy can irreversibly harm your baby’s sexual development and reproductive health. Infants fed soy formula take in an estimated five birth control pills worth of estrogen every day. Infants fed soy have had up to 20,000 times the amount of estrogen in circulation as those fed other formulas!

Women trying to conceive may want to avoid soy at all costs. Soy has a compound called genistein. Recent research on humans has shown that it impairs sperm as they swim toward the egg. Moreover, it took much smaller doses of genistein to create infertility problems in humans than it did in the mice trials.

There are a few soy products which are very good for you, but they are all fermented soy products. Tempe is a soy bean cake with a nutty, mushroom like flavor. Miso is a fermented soybean paste with a salty, buttery texture used in miso soup. Natto is fermented soybeans, almost like a strong cheese. And, of course, the one we all know, soy sauce, is fermented soy, salt and enzymes. Be careful to get real soy sauce, not the artificially made and chemically altered stuff. Notice that tofu is not on this list, as well as soy milk. Neither are a healthy alternative. All of those fermented soy products have huge amounts of vitamin K2, a very necessary vitamin. Unfortunately, those don’t even sound like things I’d eat, but you can if you want. I’ll stick to dark green vegetables for my vitamin K!

As always, don’t take my word as gospel. Do some research if this topic interests you. Go to Mercola.com, articles, and type in soy. That will get you started in your search for answers.