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Do real men eat soy? Perhaps. But if they want to become fathers, they may want to limit their tofu intake. A new study shows that downing soy products may lower sperm count. The reason, according to the research published in the journal Human Reproduction (pdf): soy beans contain high amounts of phytoestrogens, organic compounds that mimic the female hormone estrogen in the human body and, in animal studies, have been shown to reduce testosterone levels. Lead study author Jorge Chavarro, a research fellow in the Department of Nutrition at the Harvard School of Public Health,and his colleagues found that men who ate at least half a serving a day of soy had, on average, 34 million fewer sperm per milliliter than those who skipped it. But Chavarro doesn't recommend you give up the soy burgers—at least not yet. He notes that the study was limited (99 men) and that more research is needed to prove that tofu actually reduces male fertility.

11 Comments

1. 1. annperdue 08:49 PM 7/23/08

   Since I am female and I eat lots of soy, does that mean the soy lowers my testosterone level? I describe myself as a very non-violent and compassionate individual, and I feel that testosterone excess in this world can lead to violence. Hormone levels effect on our brain chemstry too. I hope this article won't discourage real men from eating soy. There are both male and female characteristics in everyone.

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2. 2. mcross 10:29 PM 7/23/08

   I have read an article about the ill effects of soy, and now this. Does anyone read the labels on the food they eat? It is now in everything. I wonder how we are having babies at all with the level of soy product we are forced to eat. I can't find much on the shelf that doesn't contain some of it, if it doesn't at least have soy bean oil in it. We are probably all being poisoned with it by the food industry who is trying to make a buck off our need to feed.

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3. 3. Blackpriester 03:50 AM 7/24/08

   Ann,
   
   Unfortunately the interaction of hormones with health and behavior is a little more complex than you suggest. Low testosterone levels are bad for your health in many way, not just reproductive ones. For example, low "Test" lead to loss of muscle mass and gain in fattty tissue. Also, the male body will react with a higher glandular production of testosterone, possibly increasing hair loss. May I also allow myself the conjecture that you might not have a lot of sex, if your testosterone level is very low? Yes, women need it too to get aroused ;).
   
   Bottom line: Don't make testosterone out to be the devil. it isn't.

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4. 4. samanthan89 11:37 PM 7/25/08

   so do you think because me and my man cant have sex we have been together for almost a year and he is a vegetarian that it may be because of his soy intake of the low sex esteem we also try to hvae ababy and it isnt working

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5. 5. venkythedoc 03:04 AM 7/28/08

   well... study is not done in a proper scientific way.. author himself accepts that they need more study.. sample patients were all subfertile group of people...and i think it does have some confouding factors.. although.. author says they have done some changes.. chinese eat more soy than any one else.. and they have 1 billlion ppl in their country.. and india has lots of vegetarians and they have a billion too...

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6. 6. Blackpriester 06:42 AM 7/28/08

   Venky,
   
   Your posting is full of logical fallacies. May I kindly point you to http://leo.stcloudstate.edu/acadwrite/logic.html? Your "India & China" argument is a particularly egregorious example of "property in the parts". That the Chinese have a large population says nothing about their fertility (not even population GROWTH does, since it is obviously influenced by many other factors than biological fertility).
   
   Being a vegeterian is obviouls unhealthy from a purely biological and medical "performance perspective". If you do it fort moral reasons, fine.

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7. 7. JoePBlack 08:38 AM 2/15/09

   This is very interesting...but I'm wondering, where exactly the study about it took place? Was it in Europe, America, or Asia? I'm asking you this because I live in Asian Country, and on our daily meal, most of our foods always contained with soy. And as far as I know, we never have problems with fertility. In fact, we have problems with over population.
   
   http://ezinearticles.com/?Daily-Food-You-Can-Take-For-Increasing-Sperm-Count&id=1939870
   http://ezinearticles.com/?Ultimate-Ways-to-Conquer-Your-Low-Sperm-Count&id=1931567

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8. 8. JoePBlack 08:49 AM 2/15/09

   This is very <a target="_new" href="http://ezinearticles.com/?Daily-Food-You-Can-Take-For-Increasing-Sperm-Count&id=1939870">interesting</a. ...but I'm wondering, where exactly the study about it took place? Was it in Europe, America, or Asia? I'm asking you this because I live in Asian Country, and on our daily meal, most of our foods always contained with soy. And as far as I know, we never have problems with fertility. In fact, we have problems with over population.
   

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9. 9. Johan 06:56 PM 7/27/09

   Strange! I've been vegan since 2000 but I like to have sex every day, my girlfriend is vegetarian. I eat sometimes soy burger - maybe once or twice a week) but do not like soy-milk. But I can't resist having sex :-D

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10. 10. eliezerluardo 03:09 PM 10/1/10

    I sometimes used to eat soy beans , I really don't know that it can lower our <a href="http://www.wyld.com.au/"><b>libido</b></a>. Thanks that you have shared this information, now I will never eat soy beans. I don't want to lose my sexual desire. I have to maintain it active.

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11. 11. JJC78 09:57 AM 3/13/12

    Eliszerluardo,
    
    You shouldn't base your diet off of one study. In fact, there is research evidence that conflicts with the conclusion articulated here. Regardless, you should consider the other health benefits and make a balanced decision.
    
    See Insights Gained from 20 Years of Soy Research J. Nutr. December 1, 2010 140:2289S-2295S (available at http://jn.nutrition.org/content/140/12/2289S.full).
    
    Note that this review of the scientific evidence states that "[t]he estrogen-like effects of isoflavones have also raised concern that soyfoods exert feminizing effects in men, such as causing gynecomastia (85) and reducing circulating testosterone levels (86) and sperm concentration (87). However, the totality of evidence, especially the clinical data, indicate feminization concerns are unwarranted; feminizing effects or not observed in response to isoflavone exposure equal to or greatly exceeding typical Asian intake regardless of whether exposure occurs via supplements or traditional soyfoods [see reference (88) for a review of this topic]."

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