Guys, You Might Want to Back Away from the Edamame


UroToday ("Breaking Urology News written by Urologists for Urologists") is reporting a study in the journal Fertility and Sterility that finds that eating soy products might affect semen quality. To wit:

There was an inverse association between soy food intake and sperm concentration that remained significant when evaluated with respect to age, abstinence, body mass, and caffeine, each of tobacco intake. There was no impact on sperm motility of morphology.

Access the UroToday report of the study here.

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  1. Note to all single males–eat more sushi.

  2. Not supprising when one considers that soy contains estrogenic compounds.

  3. You’ll get man-boobs, if nothing else.

  4. This is not news to bodybuilders, who have avoideded soy and soy proteins for ages due to estrogenic properties

  5. Not supprising when one considers that soy contains estrogenic compounds.

    Very true.

    Also, Soy really isn’t as healthy as people make it out to be. And the treatment that soy beans go through in order to make them palatable further reduces the health benefits of soy.

  6. Jack | November 1, 2007, 1:12pm | #

    This is not news to bodybuilders

    …who already have shriveled dicks from steroid use.

  7. Like I needed another reason not to eat tofu.

  8. There is finally a vaccine for child-support.

  9. Then why are there so many asians on this planet?

  10. Then why are there so many asians on this planet?

    Cause they’re hot…

  11. soy contains estrogenic compounds.

    So its not a coincidence that the most feminized segment of society – your hard-core hippy/alternative types – eat tofu and drink soymilk.

  12. Then why are there so many asians on this planet?

    Cause they’re hot…

    That is correct. Taktrix?, would you like to go on to the bonus round?

  13. Heh. On my browser this post is right next to the attractive woman wearing the “I survived Roe v. Wade” T-Shirt.

  14. “So its not a coincidence that the most feminized segment of society – your hard-core hippy/alternative types – eat tofu and drink soymilk.”

    Clearly you have not seen the manly men of National Review.

  15. But does it affect the taste?

  16. So do the women become more reproductive while the men become less?

  17. So its not a coincidence that the most feminized segment of society – your hard-core hippy/alternative types – eat tofu and drink soymilk.

    Here’s Hugh Hewitt running in the Real Men Go To Tehran 10K Fun Run (SFW but a little gross nevertheless).

  18. Could this explain the bukkake phenomenon?

  19. Two porno actresses told me that pineapples, juice too, makes semen taste good. I take them at their word. Both have been in the business seven years plus. I know, they showed me the videos and DVDs.

  20. Even knowing it makes my semen taste better, I think I’ll still not drink pineapplejuice.

  21. I GOTTA PEE!

  22. Clearly you have not seen the manly men of National Review.

    Nor do I care to, thanks.

    Here’s Hugh Hewitt running in the Real Men Go To Tehran 10K Fun Run

    No way I’m clicking on that link. What, do I look stupid?

  23. I GOTTA PEE!

    Too much pineapple juice eh?????

  24. R C Dean,

    What you’re afraid of a little sweaty manboob action?

  25. Young asian men are plenty fertile, but the phytoestrogen takes its toll over time.

    Relates to the low rates of prostate cancer in asian societies as well.

  26. Here’s Hugh Hewitt running in the Real Men Go To Tehran 10K Fun Run

    Oh, I look stupid. Should I be clicking on that link?

  27. …the treatment that soy beans go through in order to make them palatable…

    What treatment? You cook the things raw in the pod and eat them. Or you can buy the beans dried and boil them in the pressure cooker. To make soymilk, you grind them, boil the ground beans in water, and strain the cooking water, which is now soymilk. If you want tofu, you can add lemon juice or magnesium sulfate (traditionally produced in the process of refining salt from seawater) to the soymilk and letting it coagulate. I mean, we are not exactly talking artificial colors and flavors here.

  28. Pineapple juice is sounding better now! PTOOOOOOOOOOOUI!!!!!

  29. “This is not news to bodybuilders”

    or anybody who knows about nutrition. soy is estrogenic. that’s why (among other reasons) most bodybuilders and strength athletes only use soy protein sparingly. this has been known for decades. it figures that the conventional medical establishment is starting to catch on (sports scientists etc. also were decades ahead on omega oils, ketogenic diets etc.)

    “…who already have shriveled dicks from steroid use.”

    actually, it’s the testicles that shrink, not the penis.

    the shrinking can be avoided if patients take chorionic gonadotropin during cycle.

    iow, it’s completely avoidable.

  30. The Government classifies estrogen as an environmental toxin while testosterone is a controlled substance.

    ’nuff said

  31. there’s a reason for that.

    estrogen is bioavailable, and testosterone isn’t. that’s why the former can be taken orally (and the latter can’t unless altered by methylation or the adding of certain esters (which is weak) to survive first pass metabolism, etc.).

    there is TONS of estrogen in the water supply/environment because so much has been urinatedout into the water table, and women have been using birth control pills for decades.

    environmental estrogens are bad enough (plastics, etc.) but it’s even worse due to the years of injection of estrogen by women…

    fwiw, as i stated in another post – both the DEA and AMA testified AGAINST making testosterone and other AAS into controlled substances. it was done “for the children” as most bad/nannystate legislation is justified


  33. “…who already have shriveled dicks from steroid use.”

    actually, it’s the testicles that shrink, not the penis.

    I’m pretty sure the penises are small to begin with. Why do you think they got into bodybuilding in the first place!

  34. as a powerlifter and olympic style weightlifter (two strength sports that have a longgoing friendly rivalry with bodybuilding) i am contractually obligated to agree Taktix.

  35. guys hey tofu is nice once in a while with a red curry or even some string beans and a zesty chili paste.

    fer reals.

  36. Soy sucks.

    Scientists Protest Soy Approval in Unusual Letter
    Scientists’ Letter

    DEPARTMENT OF HEALTH and HUMAN SERVICES Public Health Service Food and Drug Administration National Center For Toxicological Research Jefferson, Ark. 72079-9502 Daniel M. Sheehan, Ph.D . Director, Estrogen Base Program Division of Genetic and Reproductive Toxicology and Daniel R. Doerge, Ph.D. Division of Biochemical Toxicology February 18, 1999 Dockets Management Branch (HFA-305) Food and Drug Administration Rockville, MD 20852

    To whom it may concern,

    We are writing in reference to Docket # 98P-0683; “Food Labeling: Health Claims; Soy Protein and Coronary Heart Disease.” We oppose this health claim because there is abundant evidence that some of the isoflavones found in soy, including genistein and equol, a metabolize of daidzen, demonstrate toxicity in estrogen sensitive tissues and in the thyroid. This is true for a number of species, including humans.

    Additionally, the adverse effects in humans occur in several tissues and, apparently, by several distinct mechanisms. Genistein is clearly estrogenic; it possesses the chemical structural features necessary for estrogenic activity (; Sheehan and Medlock, 1995; Tong, et al, 1997; Miksicek, 1998) and induces estrogenic responses in developing and adult animals and in adult humans.

    In rodents, equol is estrogenic and acts as an estrogenic endocrine disruptor during development (Medlock, et al, 1995a,b). Faber and Hughes (1993) showed alterations in LH regulation following this developmental treatment with genistein. Thus, during pregnancy in humans, isoflavones per se could be a risk factor for abnormal brain and reproductive tract development.

    Furthermore, pregnant Rhesus monkeys fed genistein had serum estradiol levels 50- 100 percent higher than the controls in three different areas of the maternal circulation (Harrison, et al, 1998). Given that the Rhesus monkey is the best experimental model for humans, and that a women’s own estrogens are a very significant risk factor for breast cancer, it is unreasonable to approve the health claim until complete safety studies of soy protein are conducted.

    Of equally grave concern is the finding that the fetuses of genistein fed monkeys had a 70 percent higher serum estradiol level than did the controls (Harrison, et al, 1998). Development is recognized as the most sensitive life stage for estrogen toxicity because of the indisputable evidence of a very wide variety of frank malformations and serious functional deficits in experimental animals and humans.

    In the human population, DES exposure stands as a prime example of adverse estrogenic effects during development. About 50 percent of the female offspring and a smaller fraction of male offspring displayed one or more malformations in the reproductive tract, as well as a lower prevalence (about 1 in a thousand) of malignancies.

    In adults, genistein could be a risk factor for a number of estrogen-associated diseases. Even without the evidence of elevated serum estradiol levels in Rhesus fetuses, potency and dose differences between DES and the soy isoflavones do not provide any assurance that the soy protein isoflavones per se will be without adverse effects.

    First, calculations, based on the literature, show that doses of soy protein isoflavones used in clinical trials which demonstrated estrogenic effects were as potent as low but active doses of DES in Rhesus monkeys (Sheehan, unpublished data). Second, we have recently shown that estradiol shows no threshold in an extremely large dose-response experiment (Sheehan, et al, 1999), and we subsequently have found 31 dose-response curves for hormone-mimicking chemicals that also fail to show a threshold (Sheehan, 1998a).

    Our conclusions are that no dose is without risk; the extent of risk is simply a function of dose. These two features support and extend the conclusion that it is inappropriate to allow health claims for soy protein isolate. Additionally, isoflavones are inhibitors of the thyroid peroxidase which makes T3 and T4. Inhibition can be expected to generate thyroid abnormalities, including goiter and autoimmune thyroiditis. There exists a significant body of animal data that demonstrates goitrogenic and even carcinogenic effects of soy products (cf., Kimura et al., 1976). Moreover, there are significant reports of goitrogenic effects from soy consumption in human infants (cf., Van Wyk et al., 1959; Hydovitz, 1960; Shepard et al., 1960; Pinchers et al., 1965; Chorazy et al., 1995) and adults (McCarrison, 1933; Ishizuki, et al., 1991).

    Recently, we have identified genistein and daidzein as the goitrogenic isoflavonoid components of soy and defined the mechanisms for inhibition of thyroid peroxidase (TPO)- catalyzed thyroid hormone synthesis in vitro (Divi et al., 1997; Divi et al., 1996). The observed suicide inactivation of TPO by isoflavones, through covalent binding to TPO, raises the possibility of neoantigen formation and because anti-TPO is the principal autoantibody present in auto immune thyroid disease. This hypothetical mechanism is consistent with the reports of Fort et al. (1986, 1990) of a doubling of risk for autoimmune thyroiditis in children who had received soy formulas as infants compared to infants receiving other forms of milk.

    The serum levels of isoflavones in infants receiving soy formula that are about five times higher than in women receiving soy supplements who show menstrual cycle disturbances, including an increased estradiol level in the follicular phase (Setchell, et al, 1997). Assuming a dose-dependent risk, it is unreasonable to assert that the infant findings are irrelevant to adults who may consume smaller amounts of isoflavones.

    Additionally, while there is an unambiguous biological effect on menstrual cycle length (Cassidy, et al, 1994), it is unclear whether the soy effects are beneficial or adverse. Furthermore, we need to be concerned about transplacental passage of isoflavones as the DES case has shown us that estrogens can pass the placenta. No such studies have been conducted with genistein in humans or primates. As all estrogens which have been studied carefully in human populations are two-edged swords in humans (Sheehan and Medlock, 1995; Sheehan, 1997), with both beneficial and adverse effects resulting from the administration of the same estrogen, it is likely that the same characteristic is shared by the isoflavones. The animal data is also consistent with adverse effects in humans.

    Finally, initial data fi-om a robust (7,000 men) long-term (30+ years) prospective epidemiological study in Hawaii showed that Alzheimer’s disease prevalence in Hawaiian men was similar to European-ancestry Americans and to Japanese (White, et al, 1996a). In contrast, vascular dementia prevalence is similar in Hawaii and Japan and both are higher than in European-ancestry Americans.

    This suggests that common ancestry or environmental factors in Japan and Hawaii are responsible for the higher prevalence of vascular dementia in these locations. Subsequently, this same group showed a significant dose-dependent risk (up to 2.4 fold) for development of vascular dementia and brain atrophy from consumption of tofu, a soy product rich in isoflavones (White, et al, 1996b).

    This finding is consistent with the environmental causation suggested from the earlier analysis, and provides evidence that soy (tofu) phytoestrogens causes vascular dementia. Given that estrogens are important for maintenance of brain function in women; that the male brain contains aromatase, the enzyme that converts testosterone to estradiol; and that isoflavones inhibit this enzymatic activity (Irvine, 1998), there is a mechanistic basis for the human findings. Given the great difficulty in discerning the relationship between exposures and long latency adverse effects in the human population (Sheehan, 1998b), and the potential mechanistic explanation for the epidemiological findings, this is an important study.

    It is one of the more robust, well-designed prospective epidemiological studies generally available. We rarely have such power in human studies, as well as a potential mechanism, and thus the results should be interpreted in this context. Does the Asian experience provide us with reassurance that the isoflavones are safe? A review of several examples lead to the conclusion, – “Given the parallels with herbal medicines with respect to attitudes, monitoring deficiencies, and the general difficulty of detecting toxicities with long Iatencies, I am unconvinced that the long history of apparent safe use of soy products can provide confidence that they are indeed without risk.” (Sheehan, 1998b).

    It should also be noted that the claim on p. 62978 that soy protein foods are GRAS is in conflict with the recent return by CFSAN to Archer Daniels Midland of a petition for GRAS status for soy protein because of deficiencies in reporting adverse effects in the petition. Thus GRAS status has not been granted. Linda Kahl can provide you with details. It would seem appropriate for FDA to speak with a single voice regarding soy protein isolate. Taken together, the findings presented here are self-consistent and demonstrate that genistein and other isoflavones can have adverse effects in a variety of species, including humans. Animal studies are the front line in evaluating toxicity, as they predict, with good accuracy, adverse effects in humans.

    For the isoflavones, we additionally have evidence of two types of adverse effects in humans, despite the very few studies that have addressed this subject. While isoflavones may have beneficial effects at some ages or circumstances, this cannot be assumed to be true at all ages. Isoflavones are like other estrogens in that they are two-edged swords, conferring both benefits and risk (Sheehan and Medlock, 1995; Sheehan, 1997).

    The health labeling of soy protein isolate for foods needs to considered just as would the addition of any estrogen or goitrogen to foods, which are bad ideas. Estrogenic and goitrogenic drugs are regulated by FDA, and are taken under a physician’s care. Patients are informed of risks, and are monitored by their physicians for evidence of toxicity. There are no similar safeguards in place for foods, so the public will be put at potential risk from soy isoflavones in soy protein isolate without adequate warning and information.

    Finally, NCTR is currently conducting a long-term multigeneration study of genistein administered in feed to rats. The analysis of the dose range-finding studies are nearly complete now. As preliminary data, which is still confidential, may be relevant to your decision, I suggest you contact Dr. Barry Delclos at the address on the letterhead, or email him.


    Daniel M. Sheehan
    Daniel R. Doerge

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