Read all of Rutz’s columns on soy for the whole story:

Soy is making kids ‘gay’
The trouble with soy – part 2
The trouble with soy – part 3
The trouble with soy – part 4
The trouble with soy – part 5

The shock waves from my last three columns continue to reverberate around the world. The fan mail is in three main categories:

  1. “You didn’t tell the half of it. Why don’t you tell folks how bad soy really is?”

  2. “Help! My family has been hit hard by soy. What can we do about it now? Are there any ways to reverse the effects?”

  3. Then there are the letters written in blood on asbestos. Actual quotes from some of the cleaner ones:

    A. “Your article proved the following: a) you are an idiot, b) you [sic] a bastard, c) you should be prevented from publishing anything ever again, and d) once again, you are an idiot.”

    B. “are you an idiot? what’s your next theory … eating chicken wings makes people black?”


    D. “An ignorant person might be able to believe these lies, but someone who actually knows the facts will not be so easily fooled. This artical [sic] is a ridiculous waste of space. It’s ludacris [sic].”

    E. “Everything about … your article … is ignorant and filled with hate. Your blatant homophobia is buffered by your use of dismissible scientific theories. You are clearly targeting gay men with your hate filled article and essentially promoting ignorance, fear and hate.”

After 76 columns for WorldNetDaily, I’ve become accustomed to barbed feedback, but mostly the polite, Republican type of badinage. However, since my Dec. 12 column got picked up by the big homosexual/liberal websites, the range of responses has widened to include the obscene, the vulgar and the stupendously naive. Also, it’s fascinating to note that the letters seething with hatred usually accuse me of hate. Ah well, it’s nice to know I appeal to a variety of readers.

This week I take temporary leave of the homosexuality issue to touch upon two other serious soy-product problems: breast/prostate cancer and being overweight.

Is the death rate from breast and prostate cancers much lower in Asia? Absolutely. No argument. But they do have higher rates of even more lethal cancers, namely liver, esophageal, pancreatic and stomach cancers. And remember that Asians don’t eat much soy. That’s lucky for them because soy estrogens are as likely to promote breast and prostate cancers as to stop them.[1-2]

We know that because researchers at the University of Illinois used soy isoflavones to induce mammary tumors in mice but saw them regress after being switched back to a diet low in soy estrogens. (The more isoflavones, the more risk.) Because the worst effects were experienced by mice with very low pre-existing estrogen levels, the researchers concluded that soy is riskiest for women during their menopause years.[3, 4] However, it’s not good for younger women, either, as University of California researchers found a “stimulatory effect on the premenopausal female breast.”[5] And there are lots more studies besides these.

That’s why Dr. Regina G. Ziegler of the National Cancer Institute has expressed worries about the soy fad and recommends that women be “cautious.”[6] Cornell University has homed in on women with a family history of breast cancer and suggested they be especially cautious about their soy intake.[7] The Israeli and French governments have issued strong warnings.[8,9] (That’s enough to convince me to warn you in these columns.)

The soy industry, of course, trots out lots of studies saying the opposite. Lately it’s been tripping on the idea that soy prevents breast cancer best of all when women eat lots of it during adolescence. In other words, “get ’em young.” Indeed, a recent human study presented slight evidence that this might be true.[10] But can you trust a study based on dietary recall? I can’t remember what I ate last week, but these women supposedly remembered every cake of tofu they downed years ago. With the studies on adolescent rats, we know exactly what they ate and how it all turned out. One study carried the good news headline “Soy protects rats against breast cancer.” But wait – what’s buried deep down in the text? Those rats also experienced an “advance in vaginal opening.” In plain English, premature puberty![11] Is that the kind of “protection” you want for your daughter?

The soy industry also has men in their sights. Soy, they claim, is the answer for preventing prostate cancer. What nobody’s telling our men is that IF soy prevents cancer, it’s probably because it lowers testosterone![12-15] And less often, it’s because soy decreases prostate weight. Their “good news” often comes with other side effects, too, like decreased brain weight and changes to the sexually dimorphic brain.[16,17]

The sexually dimorphic brain is part of the hypothalamus that is super-sensitive to hormones – the estrogen that keeps our women womanly and testosterone that keeps our men manly. Interestingly enough, homosexuals have different structures to their hypothalamuses, with some areas more like females than straight males.[18] So, brother, if feminizing yourself sounds like a good way to prevent prostate cancer, then put soy on your menu. Just know that this course of action does not come highly recommended. Top scientists at the FDA’s National Laboratory for Toxicological Research found that isoflavones interfere with hormone receptors in the prostate gland and that this is likely to have “implications for reproductive toxicity and carcinogenesis.”[19]

“Well,” you may say, “soy will at least keep me and my kids from getting fat.” That idea, too, comes straight from the soy industry, which has an $80 million annual PR budget and works overtime to come up with “initiatives” with cute names like “Isoy.”?[20] Click here for a clever example of the United Soybean Board’s efforts to reach out to your children. Their bright idea is to push “healthy” low-fat soy protein products into our schools.

Could that work? Fat chance. Farmers give animals soy feed to fatten them for slaughter as fast as possible. Isoflavones interfere with the thyroid gland’s ability to manufacture thyroid hormones, and that means weight gain, tiredness and depression. Now frankly, I don’t care if Bessie was depressed on the day she moooved on to that Great Meadow in the Sky, but I do care if 300 million fellow Americans turn into walking blobs because they were conned into thinking soy is the best weight-loss food since the celery and water diet.

To date, the best research on soy and the thyroid comes from Japan, home of the world’s finest thyroid clinics. When thyroid specialists there experimented on healthy Japanese men and women, they saw their thyroids fry within three short months of increased soybean intake.[21]

The people studied weren’t eating soy for breakfast, lunch and dinner. They weren’t even popping soy supplements. These human lab rats were downing just enough soy foods to give them about 35 milligrams a day of isoflavones ? 10 milligrams less than you get in one glass of soy milk! But their thyroids paid a steep price. And with a weakened thyroid, you’ll find it harder and harder to lose any weight at all. And you won’t be too cheerful, either.

Next week I’ll touch on the question, “If soy is no good, what can I eat instead?” Also, I’ll discuss heart disease and why the American Heart Association no longer is in love with soy.

  1. Daniel, Kaayla T. “The Whole Soy Story: The Dark Side of America’s Favorite Health Food” (New Trends, 2004), 379-94. Overview of how soy can cause, contribute to or accelerate the growth of cancers, including 131 references.

  2. Fallon, S, Daniel KT, Sanda W. responses to Docket 2004Q-0151 Solae Company Health Calim on Cancer. Documents submitted to the FDA, June 14, 2004, Jan. 20, 2005, and April 11, 2005. Posted at under “Soy Alert.”

  3. Ju YK, Allred KF et al. Genistein stimulates growth of human breast cancer cells in a novel, postmenopausal animal model, with low plasma estradiol concentrations. Carcinogenesis, 2006, June; 27 (6), 1292-9.

  4. Allred CD, Allred KF et al. Dietary genistein results in larger MNU-induced estrogen-dependent mammary tumors following ovariectomy of Sprague-Dawley rats. Carcinogenesis, 2004, February; 25 (2); 211-8.

  5. Petrakis NL, Barnes S et al. Stimulatory influence of soy protein isolate on breast secretion in pre- and postmenopausal women. Cancer Epidemiol Biomarkers Prev, 1996, 5, (10); 785-94.

  6. Ziegler, RG. Comment on phytoestrogens and breast cancer. Am J Clin Nutr, 2004, 79 (2); 183-4.

  7. Women cautioned against using herbal supplements, Science Daily, July 13, 2005.

  8. Siegel-Itzkovich J. Health Committee warns of potential dangers of soya. BMJ, 2005, July 30, 331, 7511, 254.

  9. Press release, AFSSA (Agence Francaise de Securite Sanitarie des Aliments – French Food Safety Agency), March 9, 2005. Translation available online at

  10. Consuming soy in childhood linked to lower breast cancer risk. The Soy Daily, Nov. 17, 2006.

  11. Hakkak R, Korourian S et al. Diets containing whey proteins or soy protein isolate protect against 7, 12-dimethylbenz (a) anthracene-induced mammary tumors in female rats. Cancer Epidemiol Biomarkers Prev, 2000, 9 (13), 117.

  12. Pollard M Wolter W. Sun L. Diet and the duration of testosterone-dependent prostate cancer in Lobund-Wister rats. Cancer Letter, 2001 Nov 28; 173 (2); 127-31.

  13. Pollard M, Wolter W. Prevention of prostate-related cancer in Lobund-Wister rats by a soy protein isolate/isoflavone diet. Prostate, 2000, Oct 1; 45 (2); 101-5.

  14. Pollard M, Wolter W, Sun L. Prevention of induced prostate-related cancer by soy protein isolate/isoflavone-supplemented diet in Lobund-Wistar rats. In Vivo, 2000 May-June; 14 (3); 389-92.

  15. Weber KS, Setchell KD et al. Dietary soy-phytoestrogens decrease testosterone levels and prostate weight without altering LH, prostate 5alpha-reductatse or testicular steroidogenic acute regulatory peptide levels in adult male Sprague-Dawley rats. J Endocrinol, 2001 Sep: 170 (3)591-9.

  16. Lephart ED, Setchell KD, Lund TD. Phytoestrogens: hormonal action and brain plasticity. Brain Res Bull, 2005 Apr 15; 65 (3): 193-8.

  17. Lephart ED, Rhees RW et al. Estrogens and phytoestrogens: brain plasticity of sexually dimorphic brain volumes. J Steroid Biochem Mol Biol, 2003 June; 85 (2-5): 299-309.

  18. Johnson, Ryan D. Homosexuality: Nature or Nurture, AllPsych Journal, April 30, 2003.

  19. Doerge D, Chang H. Inactivation of thyroid peroxidase by soy isoflavones in vitro and in vivo. J. Chromatogr Analyt Technolo Biomed Life Sci, 2002, 777, (1-2); 269.


  21. Ishizuki, Hirooka et al. The effects on the thyroid gland of soybeans administer experimentally i healthy subjects. Nippon Naibundi gakkai Zasshi, 1991 (67); 622-29. Translation by Japan Communication Service, Wellington, NZ.

Note: Read our discussion guidelines before commenting.