Can soy be used as an aid to celibacy? Is it true that Zen monks eat soy because naughty behavior goes down when tofu consumption goes up? Do Japanese wives feed unfaithful husbands extra helpings of soy? Could politicians with the “zipper problem” better control their errant behavior if they consumed enough soy?
Anecdotally, the answer is, yes, and a fair amount of science backs it up. To date, many studies show that soy’s estrogenic isoflavones interfere with the production and usage of testosterone in the body. Some evidence points to soy as a feminizing influence that can lead to gynecomastia (man breasts). And there’s massive evidence of reproductive toxicity.
The latest news is a case study in the journal Nutrition. The subject is a 19-year-old heterosexual man who become vegan, began consuming a lot of soy, and, soon after, experienced loss of libido and erectile dysfunction. Prior to adopting veganism, he had an active sex life with no reported problems.
Lab assessment revealed low levels of free and total testosterone with increased levels of DHEA. During the year prior to this workup, the young man’s diet had packed a whopping punch of soy isoflavones, averaging 360 mg per day, from soy milk, soy crisps, tofu, soy sauce, soy nuts and edamame. This level of soy consumption is far above average, yet increasingly common these days as people quit meat and dairy products for soy substitutes. Prior to becoming vegan, the man had been on a Standard American Diet (SAD). After discontinuing his vegan diet and eliminating soy foods altogether, he noticed a gradual improvement in sexual function over the course of a year and his lab tests revealed gradual normalization of testosterone and DHEA levels.
The researchers conclude with the usual caveat “more studies are needed.” Yes, indeed, and as soy consumption increases, doctors and other health practitioners will most likely report many such cases. Let’s hope future studies focus on women as well as men, and include a study on the link between sex, soy and vulvodynia. What to do now? The science may not be entirely in, but the message is already clear: “If you love and respect your naughty bits, Practice Safe Soy.”
To read the study:
Hypogonadism and erectile dysfunction associated with soy product consumption.Siepmann T, Roofeh J, Kiefer FW, Edelson DG.Nutrition. 2011 Jul-Aug;27(7-8):859-62. Epub 2011 Feb 25.
For more about soy and reproduction, including citations, read chapter 29 of The Whole Soy Story: The Dark Side of America’s Favorite Health Food. For information on how much soy is safe to eat read “Soy Alert” articles and blogs on this website, and also visit: www.naughtynutritionist.com/naughtynutritionist.com/Practice_Safe_Soy.html
Thanks to Sylvia Onusic for alerting me to this article.
Kaayla, thanks for the great educational information. A bit more anecdotal… I have a son who went on a soy binge in his teenage years for the reason of sparing animals, quite like the young man in your article. My son developed gynecomastia and to this day, even after reverting back to his former omnivore ways, the gynecomastia remains. Some time back there was quite a large article in the New York Times about gynecomastia. The cause? The author had no clue- he just wanted the public to know that it can be remedied through plastic surgery!
We use soy as a dairy substitute as our son is allergic to all milk products. Is the occassional tofu mixed pumpkin pie gonna hurt?