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Soy's effect on men's testosterone

I am a vegan but I'm trying to get my b/f to be a vegan too. He's starting out vegetarianism slowly but he's very concerned about soy and how it effects men's testosterone level. He's restricting his soy consumption and prefers to drink rice milk over soy milk. He also loves to work out and he's afraid that the soy will prevent him from fully developing his muscles. He has this crazy obsession of reading men's health magazine and there has been several articles that gave soy a bad rap. He also gets a lot of men's health information from his dad who is very knowledgeable in that area so he really trust his dad's words.

I also plan on having vegan children and he's also concerned for any male children that we might have. He said he read somewhere that soy will affect how male children's reproductive system will develop when they ingest large quantities of soy. He's afraid that if we do have male children they'll have a traumatizing life because they won't be able to snatch some girls with his unappealing sex organ. HAHAHAH

I think it's completely bull but I might be a bit bias since I x3 anything vegan :D. I just want to have some opinions. It would be great if anyone can provide scientific articles that can argue against what my b/f has been reading. It would also be great if any male vegans would like to prove my b/f wrong. If anyone has had experience raising male vegan children that would be a plus too  ;)b


What it comes down to is that the jury is still pretty much out, simply because almost all these studies were done on animals (and so the senseless use of animals continues to make our lives "better").  If he complains that these two articles are biased because of the sites I got them from, you could kindly point out that the second one cites many credible sources for their statements.  Just because an article about vegetarianism/veganism comes from a veg, doesn't mean that one can assume that it's a blind endorsement for all things veg - in this case the author is responding to the soy/testosterone controversy (as well as several others).  She's not just writing "Soy is good, go eat it," she's pointing out the how and why of what the recent arguments against it have said.

As an aside, here's a sentence from that second article (no offense to the website) that confuses me: "Dr. Badger did note that animal studies are not always flawed by virtue of the fact that they were done on non-human animals and the flaws found varied depending on the studies."  What the heck is a "non-human animal"?  They're all non-human!  I don't care how many chromosomes or DNA markers we have in common with primates, they're still not humans!  STOP TESTING ON THEM TO FIND OUT HOW THINGS WOULD REACT ON US!  IF YOU WANT TO KNOW, TEST ON US!  If there's cause for concern, wouldn't common sense tell you to not market the thing?  "Hey, I have this drink that may cause your heart to explode.  Let's inject thousands of rats with the equivalent of instantly ingesting 100 servings of the stuff and see what happens!"  Where's the logic in that?!

Sorry.  I feel better now.


I've been eating soy in abundance for the last 8 years, and I have not felt any strange effects.  I've also developed some decent muscle from the average amount of exercise I do, though if your bf is looking for mass, I'd suggest using spirulina.
At a veg festival in my area I met a vegan bodybuilder, and he got huge and well defined using spirulina and soy protein.


  I have heard these things too and they cause me to laugh, laugh,  :-D. I wonder which milk company or meat producer paid for this research. I have been vegan for 30 years and now work in the forests of British Columbis Canada climbing mountains every day. As to muscle development I don't know any of my fellow workers, and there are about 100 of them who are as developed as I am, and I am 55 years old! I don't do any body building besides my work. I  wash my soy burgers down with soy milk and finish it off with soy ice cream. I am still waiting for all that soy to affect my  testosterone levels as i have seven children the youngest one is 7 years old and the oldest 28. I guess I could let my wife who is 39 tell you about how all that soy has affected our sex life but she is kinda shy. Well I guess I will go back to laughing some more  :-D.


What the heck is a "non-human animal"?

Humans are animals.  "Non-human animals" are animals other than humans (what we commonly think of when we say "animals").


Awesome thank you everyone for your wonderful comments. I've shown the first two post to my b/f earlier this morning. I've been also bring up soy is good for you. It's good for you prostate. You don't want prostate. He said he's leaning more towards soy now.

He also said he needs I believe around over 100 something grams of protein everyday for his body building regiment calculated. I don't know...he did some calculation. That sure as hell blew me away.


you can also be vegan and eat absolutely zero soy. it's not that hard to do, especially if your diet doesn't consist of a bunch of processed foods.


While I was racing and training I wondered why I had a difficult time building muscle.
Things in question:
soy intake
alcohol intake
caloric intake

the top two were high and third was at a level not to increase body mass.
Can the diagram be open to other contributing factors? ie stress, alcohol...?


I just found this while looking at IDA's World Go Vegan Days site:


just make sure you are getting organic soy, a lot of that stuff is genetically modified and a lot of soy oils and powders are processed with a chemical called hexane. Stick to products made with whole soy instead of soy protein isolates for protein. There are a lot of "studies" that point out many flaws in soy but I'm starting to believe that they are all funded by the meat/dairy industries when soy was getting popular as a "super food" and people were eating lots of veggie burgers and soy milk.


I am not big on meat analogs, and as such do not eat as much soy as many of the people here.  However, I must add that most of the negative things said about soy refer to the highly processed forms which are commonly found in nonvegan processed foods.  Start feading labels in the stores.  Almost all process meat items contain soy protein isolates or the like.  Being a nonvegan does not mean that you consume less soy, especially if you eat a lot of processed foods.  Vegans tend to eat more whole soy foods, unless your a meat analog junkie. 

As Hespedal said, it is fully possible to be vegan and consume no soy.  The last time I did the research the only confirmed complication of soy cosumption and male organs was that consuming large amounts of soy around the 6-9th week of pregnancy can lead to a defect in which the child's urethra doesn't line up with the tip of the penis.  This is a very common defect though, even amoung nonvegans.  High-fat, low-fiber diets have been shown to lead to not only prostate issues, but issues with the proper decending of the testicles amoung other things. 

Oh and by the way, most of the antisoy propaganda comes from Dr. Mercola and his organization.  Read some of the other things he recommends before you take his advice too seriously. 


I read an article about the "dangers of soy" for men and it turned out the guy they highlighted that had negative effects drank 4 quarts of soy milk a day.

So far moderate to large consumption of soy hasn't proven to be harmful to men.  In countries like Japan and Tawain where tofu, miso, etc. are staple foods the men and their boys fair well.  Prostate cancer is relatively rare in these men.

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