Submitted By: various

Here are some examples of letters I've received regarding the soy controversy:

I've been experiencing great success on your NHE program for 3 years now. I thoroughly enjoy the clarity and accuracy of your writing and analysis and where adherence to NHE has brought me.

Recently I was looking to change my supplement intake and was introduced to a multivitamin / mineral product that had 7 grams of isolated soy protein per serving. I have been consuming it now for a month noting mostly positive with couple of negative responses I've had to it.

It's been a while since I've consumed anything with soy in it and so I searched the internet for articles regarding soy's safety and came up with large numbers of articles for and against it. One particular site by a Dr. Mercola detailed soy's downside describing the dangers it presents being, estrogen disruption causing impairment of cognitive development, goitrogen causing depression of the thyroid function, and the actions of the endocrine-disrupting isoflavones, genistein and diadzen. I have even seen articles stating that soy can even impair testosterone functioning. I was overwhelmed by it's purported negatives.

In your research have you come across studies regarding these drawbacks of soy? If so, I am wondering what your take is on it. I've seen your writing on the positives and am wondering if it is up to date.

If it is, then how do you distinguish between fact and fiction?

Jim Werner, Arlington Massachusetts

I am inquiring of your opinion on soy, which I feel may be quite relevant, considering the omnipresent theme of hormones in your books.

From a bodybuilding standpoint, a lot of bodybuilders don't like to use soy because it supposedly contains estrogen-like compounds. They argue that these can tip your estrogen/testosterone balance more towards the estrogen side, which is not the best thing as a bodybuilder.

What is your opinion on the effects of soy intake on hormone levels? I didn't really see anything in NHE about this (though I could have missed it) and you do advocate eating soy as well.

I have some low-carb tortillas that I like to eat. They contain only 5 net carbs and a whopping 14 g of fiber per wrap. However,  they contain a significant portion of soy and I just want to make  sure that eating them isn't adversely affecting my bodybuilding endeavors.

Nicholas G. Rudawski
Named Presidential Graduate Fellow
University of Florida
Materials Science and Engineering



In NHE you mentioned that soy "may" be the next superfood. I have read many many articles that are very contrary, especially concerning testosterone. It seems that many have concluded soy and its estrogenic effect to be detrimental to our health. One Anti-aging Doc actually spoke of it as poison and to avoid at all costs. Is this anti-soy craze warranted and is its effect on testosterone as bad as advertised.

Zachary Anderson
Louisville, Kentucky

During the last 10 years, soy has emerged as a major worldwide consumable commodity and the presence of genetically modified (GMO) food, particularly soy, has increased exponentially. GMO food is not necessarily unhealthy and this technology has useful applications. But it also poses an array of concerns, and soy has become increasingly associated with biotechnology. Another change is the proliferation of soy byproducts that bear  only the slightest nutritional resemblance to traditional forms of soy such as edamame, the actual soybean, and are found in many processed foods.

Consumption of traditional forms of soy has been linked with healthy cholesterol levels and lower incidence of endocrine-related malignancies, particularly prostate and breast cancer. A possibly protective role for soy against cancer and heart disease should not be automatically dismissed given the toll that these diseases inflict, and the fact that there is enough supporting research to warrant further study. Also, modest amounts of traditional forms of soy do not cause hormonal disturbances in men or women and may offer hormonal benefits (particularly in connection with estrogen/testosterone). Evidence suggests that larger amounts of soy, however, may be hormonally detrimental (particularly in connection with thyroid hormones). It is not unusual for a substance to have a good effect at one intake level and a bad effect at a much higher level. But this fact gets largely swept aside in the pitched competition for market share between the meat/dairy industry and the soy industry; and because it is easier to build a case for or against something than to see all sides of a complex issue.

In the age of high-tech food processing, the term "soy" has come to encompass a wide variety of substances. Are we talking about the unprocessed forms that are a significant constituent of traditional diets of the Japanese and other historically long-lived populations? Or are we talking about new-fashioned forms of soy, concentrates, isolates, and other soy derivatives now widely present in the manufactured food supply? To avoid confusion, future conversations about soy should begin with this distinction.