I recently had a conversation with some friends about whether eating soy products were good or bad for the body. I have read and heard things that make me believe soy is bad but during my conversation I was unable to state exactly why I thought soy was bad. I immediately went home and started researching soy.

Let me start off by saying the people I read and follow believe soy is bad for the human body. I read and follow these people because I like what they have to say. I feel aligned with most of what they believe about nutrition and the human body. I discovered most of the people that I reference in my posts while I was working on my daughters health through food and nutrition. I was very successful and my daughters health is great. So, for me and my family the people I follow and align with nutritionally have a proven track record on a very personal level. It all comes back to individuality. Do what works for you.

Based on that, here is my take on Soy. Traditionally prepared soy products are very different from the soy products available today in the United States. Traditionally prepared soy products are fermented. Traditional soy processing, the fermentation of the soy, mitigates some of soy’s harmful effects by removing some of the anti-nutrients. Traditional soy foods are Miso, Tempeh, Natto, Soy Sauce and even Tofu. Traditional tofu, the tofu that originated around the 2nd century B.C. in China was made from FERMENTED bean curd – before the days of refridgeration. Most modern tofu is NOT fermented. You can still find traditionally made, fermented tofu in some Asian markets. Traditional soy foods were consumed in small amounts as condiments. Miso soup would include a couple of small cubes of tofu. NOT a block of tofu.

One study that I came across when trying to understand the “benefits” of soy was the Okinawan Centenarian Study. I have not had the opportunity to read the entire study. I have read excerpts so that I could hopefully include some useful information in this post. First, a centenarian is a person who is 100 years old or older. The Okinawan Centenarian Study points to genetics and lifestyle as two of the main factors contributing to healthy longevity in the Okinawan community. The proponents of soy foods like to point to this study as an example of just how healthy soy is. The elders of Okinawa are said to have the highest soy consumption of any people on the planet. This is a direct quote from the study, “Okanawan elders eat an average of two servings of flavonoid-rich soy products per day.” This statement is the statement that, as far as I can tell, soy proponents use as evidence of the healthy benefits of soy.

Several things about the study had me wondering about the type of soy consumed by the Okinawan Centenarians. First they are centenarians. They are old. Really old. This makes me think of words like “traditional”. Again, I haven’t read the study but I’m wondering if the Okinawan Centenarians are eating TRADITIONALLY prepared soy foods. Also, the quote states two servings of soy “products”, not soy protein. This could imply that the Okinawan Centenarians are eating quite a bit of fermented soy as a condiment the way it was traditionally consumed. Basically, just saying they eat the most soy of anyone in the world isn’t really giving a clear picture of soy. I wonder what they would think if they were presented with “soy dogs” or a “soy burger”.

The Okinawan Centenarian Study makes me wonder about the findings of Dr. Westin A. Price. He found that indigenous tribes around the world had the greatest health because they ate the traditional foods of their ancestors. Members of these indigenous groups that adopted western foods into their diet showed signs of poor health and western disease. We are back to the word “traditional” again. I am going to guess that the Okinawan Centenarians eat a very traditional diet. I did read that most Okinawan Centenarians had gardens that they grew their own vegetables in. This would mean that more than likely, they have been eating organic, nutrient dense vegetables all of their lives. Similar to the indigenous tribes that Price studied. When Dr. Price examined and compared the nutritional density of the foods eaten by indigenous tribes he found that

“in comparison to the American diet of his day, they provided at least four times the water-soluble vitamins, calcium and other minerals, and at least TEN times the fat-soluble vitamins, from animal foods such as butter, fish eggs, shellfish, organ meats, eggs and animal fats” (westinaprice.org)

I’m going to guess the difference in nutritional value of the current Okinawan Centenarian diet compared to the American diet of TODAY is EVEN GREATER than the differences that Dr. Price saw in his time. I realize I’m getting a bit off track here but I do think it’s important to point out that (my guess is) the traditional diet of the Okinawan Centenarian couldn’t be more different than the current American diet. Especially where soy is concerned.

My take is, traditionally prepared soy foods aren’t as bad for you as the modern day processed soy products available in your local grocery store. In case you couldn’t tell, that was “the good”. Now, on to “the bad”.

The Bad

Most modern soy foods are made with Soy Protein Isolate (SPI). Soy Protein Isolate is a protein rich powder extracted from the waste produced during soy oil manufacturing. Yuck. It gets worse. In 1979 the Federation of American Societies for Experimental Biology decreed that SPI could only be safely used for sealers of cardboard packaging. (source) Yipes! This is the same Soy Protein Isolate that is found in more than 60% of foods sold in supermarkets. SPI has never been granted GRAS status by the FDA. GRAS: Generally Recognized as Safe.

Here’s a list of why (the people I follow) believe modern soy products are bad:

  • Most modern soy foods are not fermented so the toxins in the soybean are not neutralized.
  • Modern processing of soybeans denatures protein and increases carcinogen levels
  • Soybeans contain HIGH levels of Phytic Acid (Phyates) enzyme-inhibitors that block mineral absorption and can result in mineral deficiencies of calcium, zinc, iron and phosphorus.
  • Phytic Acid is found naturally in all grains (I don’t eat grains), seeds, nuts and legumes including soy (I don’t eat legumes). The overnight soaking techniques that reduce or get rid of phyates in grains, nuts, seeds and other legumes don’t work for soy. Soy is too high in Phyates. Soy needs to be FERMENTED to be digestible by humans.
  • The deficiencies in calcium and vitamin D caused by soy foods can lead to problems with bone health. *Asian cultures get calcium from bone broths and vitamin D from seafood, lard and organ meats not soy.
  • Trypsin inhibitors in soy caused stunted growth during animal tests
  • The FDA never approved GRAS status for Soy Protein Isolate because of concerns about the toxins and carcinogens present in processed soy
  • Many animal studies show that soy foods cause infertility – soy consumption enhances hair growth in middle-aged men which is an indication of low testosterone
  • Most soybeans grown in the US are genetically engineered

The Ugly: Conflicting data and the nasty fighting between those who think soy is bad and those who think soy is good.

There is conflicting data regarding soy-based diets beneficial, harmful or neutral effects on breast cancer risks. The type of soy product might be important when assessing breast cancer risks. Natural phytoestrogens found in soy have been shown to increase tumor growth in a variety of different models but highly processed soy flour that doesn’t contain these same isoflavones had no effect on the models. It appears that the different concentrations of isoflavones found in Soy Protein Isolate (remember this stuff is bad) influences mammary tumors. The amount of isoflavone consumed, not the total amount of soy protein consumed is what influences the tumors.

Epidemiological studies in China, where soy intake is a regular part of the diet suggest that regularly consuming soy-based products or other vegetables high in phytoestrogens can exert a protective influence in regard to late development of breast cancer. Again, this makes me wonder how much soy is being consumed and what types of soy. The article that I got this information from does refer to the “consumption of soy in its many forms” found regularly in Chinese women’s diets. This makes me think it isn’t necessarily heavy amounts of soy PROTEIN. You can read the article here.

There is a lot of conflicting information about Phytoestrogens and their effect on the body. The people I follow believe Phytoestrogens in soy mimic the estrogen in our bodies and create estrogen dominance. Estrogen dominance is believed to be a leading cause of breast cancer, endometriosis, uterine fibroids, infertility and low libido. That’s all sounds pretty scary. Even so, this is one thing I’m not sold on. Phytoestrogens are found in lots of foods. The highest concentrations can be found flax seed and other oilseeds followed by soybeans and tofu. The amount of phytoestrogens found in soy foods depends on the type of soybean used and the processing mechanisms. This brings me back to traditional soy processing (fermentation) and modern soy processing. Hmmm

So, if you love soy you might want to eat fermented soy products like Miso, Tempeh, Natto, or Tamari (naturally fermented soy sauce). You could even give traditionally processed fermented tofu a try if you can find it in an Asian market. As for soy milk. It is not a traditional soy product. If you look at most of the Asian culture, they eat somewhere between 9-36 grams of soy food (not soy Protein) a day compared to 240 grams in a cup of soy milk or 252 grams in a cup of tofu. Do what works for you. Find people who you align with when it comes to diet and nutrition and follow their guide lines. That’s all any of us can do.

I, for one, don’t eat soy. It’s never been a big part of my diet so it wasn’t hard to give up. I used to enjoy the occasional tofu stir fry but no big deal. I’m not lacking for yummy things to eat.

Eat Well, Feel Good, Have Fun

Links to articles I read and more information about soy.

Dangers of Soy (information about the dangers of soy and children)

FDA’s Poisonous Plants Data Base (288 references to soy toxicity)

1939 – 2008 List of Studies Showing Adverse Effects of Dietary Soy

1950 – 2010 Studies about adverse effects of Isoflavones

The Soy Ploy (more information about the dangers of soy and children)

Okinawa Centenarian Study

TenderGrassfedMeat.com (their look into the Okinawa diet)

The Anti-Soy Madness I wanted to include some information from the other side of the “soy coin”. I don’t particularly like this persons tone or her attack of the Westin Price Foundation. The Westin Price Foundation is non-profit so I’m not sure why she thinks they will lose money if people eat soy. Here is a look at their 2010 Fiscal numbers.

Honest Nutrition This is another site that is “pro” soy. I did find it interesting that he makes it clear in the comments section that he does not support Genetically Modified soy in any way shape or form. He thinks it bad. A lot of the soy in the United States in genetically modified.

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