The Hidden Dangers of Soy

[David Baxter PhD]

The Hidden Dangers of Soy
By Sajid Surve, DO, Brain Blogger
February 24, 2009

As the American diet turns towards the perception of more natural and “healthy” foods, a surge in soy products has taken hold in the market. Soy is touted as a superfood full of protein, fiber, and antioxidants, and able to do everything from lower cholesterol to fight cancer. However, not all the physiological properties of soybeans are positive. Compared to the number of outlets proclaiming the benefits of soy, relatively few sources discuss the side effects of a soy-rich diet.

Unfermented soy products like soy milk and tofu form the bulk of American soy consumption. In Asian countries, which consume higher amounts of soy overall, the predominant form is fermented as found in soy sauce and miso. The fermentation process is significant because it removes much of the biologically active phylates and isoflavones from the soy.

Phylates are a form of insoluble fiber, and in low quantities are beneficial because they can absorb low density lipoprotiens and therefore lower bad cholesterol levels. They are also known to reduce risks of gastrointestinal cancers. However, in higher quantities they can also block the absorption of other nutrients, leading to vitamin and mineral deficiencies. In particular, calcium, magnesium, copper, and zinc are prone to blockage by phylates, and this can paradoxically increase the risks of osteoporosis that soy is supposed to prevent.

Soy is purported to prevent osteoporosis because of its isoflavone content. Isoflavones are a collection of complex chemical compounds which are manufactured by plants, but physiologically similar to human proteins. One type of isoflavone found in large quantities in soy is called genistein, and in humans this protein binds with some affinity to estrogen receptors. This effect is what gives soy protein the ability to fight menopausal and premenstrual symptoms, and potentially prevent osteoporosis as mentioned above. On the contrary, overconsumption of genistein can lead to the same problems associated with high estrogen levels, namely increased risks of breast, uterine, and ovarian cancer. In males, the weak estrogen activity has translated into a reported reduction in the risk of prostate cancer. High intake has been suggested to suppress testicular cell lines, although this has not been proven. Perhaps the most widely accepted consequence of a high soy diet is an impact on thyroid function. Hypothyroidism and autoimmune disorders such as Hashimoto’s thyroiditis have been linked to excess soy intake in several animal studies.

 

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Thanks for this post , as with any foods soy should be part of a varied and balanced diet , over the years I've seen food fashions come and go . It is good to be conscious of what one is eating and how that food is produced , we are omnivores and
we do need a certain amount of animal protein. doesn't have to be meat though.
It should also be said that one should be very careful not to impose an excessive diet of soy or any other extreme food diet such as vegan etc. to young children as this can seriously harm their developement and cause later health problems

 

[Jackie]

The thing that bothers me most about this is all the alternative tablets on sale in the health food stores and chemists, for the menopause/PMT, alot have this soy in one form or another, sometimes in quite high dosage, one brand, whose name I cannot remember at the moment is even endorsed by BUPA. None of these products as I'm aware of any real warnings on about the possible dangers, infact most say they are safe and without side effects, and they are compared to HRT and all its dangers. I just feel these type of over the counter, herbal/alternative medicines should be regulated better, maybe even restricted more than they are at the moment.

 

[David Baxter PhD]

The problem is that so-called (usually self-styled) "health foods", "health supplements", "natural remedies", etc., etc., are for the most part not regulated or subject to quality control. Thus, it's generally another case of caveat emptor or "buyer beware".