Negative effects of Soy Milk (?)

Dear Cecil,

I could not find any articles in your archive discussing the possible
negative effects of soy milk on the male body. About a year ago, I switched
from drinking regular skim milk (cow milk) to a fortified, vanilla
flavoured, soy based beverage called “Silk”. I like the taste of this ‘soy
milk’, it has more protein than cow’s milk, a much longer expiry period, and
a great amount of our daily recommended vitamins. It costs about the same
as skim milk as well. I would estimate I drink about 1.5 litres of it per
My question relates to the presence of trace amounts of estrogen present in
soy and its effect on male levels of testoterone and such. Is drinking this
stuff (or soy milk in general) consistently going to reduce my sperm count,
make my breasts larger, reduce facial hair, etc. What are the long term
effects of consuming soy? I have read articles, likely put forward by the
milk industry, attacking the benefits of soy milk with claims that it can
adversely affect male fertility.
Since there are billions of Asians consuming soy regularly, I figure the
stuff cannot be all bad. However, asian males, it can be argued, also tend
to have less body hair, and more feminine-type bodies compared to North
American and European counterparts.
What is the straight dope on this subject?

Toronto, Ontario, Canada

Interesting question. Along with your observances about Asian populations, if we add San Francisco to the test pool, it looks like you may be on to something…


Soy: The Poison Seed.

AFAIK, cow’s milk is riddled with estrogen hormones as well. Soy hormones , while not necessarily “healthy,” at least a natural occurance. Dairy cows, however, are injected with hormones so that they will produce more milk.

I like soy milk intensely, and I give it to my son as well as consume it personally. However, there have been some unsettling reports on the possible carcinogen effect of massive consumption of soy products. (I apologize for having no cite, I’m on my way to work.)

If you are truly concerned about extra estrogen in your milk, I would suggest avoiding regular cow’s milk AND soy milk. Go for the organic stuff. They even sell it at Wal-Mart these days.

I, however, remain unconcerned. Perhaps it is because soy milk it so delicious …

I was encouraged to take protein supplements to make a wound heal. I was taking soy because it tastes so much better than whey. I asked my doc if this presented any problems. Here is what he said about soy protein as it relates to lifting:

Soy protein may not be as good for lifting as whey or egg. But it does have benefit for lifters and other good benefits. He says that some important amino acids are now added to quality soy protein making it a viable body mass building product. He says that it also may help reduce cholesterol.

He says that it may be a viable supplent for women with estrogen difficiency, but for men it will have no adverse affects. In short, he said that plant estrogen may be able to be used by women, but men will not absorb it or use it as estrogen.

That isn’t the same as soy milk, I know, but the principles should be the same.

Hey, I definitely have less hair, but I don’t think anyone would think I have a more feminine-type body. And it’s definitely not dependent on soy consumption, it’s just genetics.

Just remember “everything in moderation,” and you’ll be fine. Get your protein from diverse sources, not just soy. And you should probably be drinking more water, because you probably don’t need the extra calories.

Is there any evidence that these hormones make it into the end product?

That’s not universally accepted as true. AFAIK the only difference in estrogen receptors between the sexes is the number, and not the type. That said, all the cites I’ve seen for how bad soy is come dangerously close to looking they’re sponsored by the Raving Loony Brigade[sup]TM[/sup]. I’d love to see something a bit more authoritative.

Native Americans tend not to have much body hair, and they wouldn’t have eaten soy before contact with Europeans. If eating soy protein in an amount that a normal person might get from soy milk did reduce body hair, somebody would almost certainly be marketing soy products for that purpose, given the current unpopularity of body hair.

I’m not thinking it’s worth much. Some poking around reveals that he’s not a medical doctor - though he is a “Texas Complimentary and Alternative Medical Association professional member and World Sports Medicine Hall of Fame member, Dr. William Wong is a Classical Naturopath, a PhD. Exercise Physiologist, Certified Athletic Trainer (AATA), Certified Sports Medicine Trainer (ASMA), Old Rite Catholic Priest and Health/Fitness Consultant.”

He doesn’t have any training, in other words, to make the claims he’s making. And he seems to be recommending some questionable therapies involving “detoxifying” and other such voodoo. I wouldn’t particularly take his opinion seriously.

Anti-soy sites are about as authoritative as anti-milk sites. They take one study and hold it up as the final word, no matter how small the actual claim is or what other studies have to say or what populations the study uses or what other foods are eaten by the population. It’s crackpot science and often deliberate fraud.

Is It True What They Say About Soy? from the UC Berkeley Wellness Letter, November 2002 has a much more balanced treatment that shows how equivocal the studies are and how little we yet know about specific effects, negative or positive, from soy.

Right now there is just no evidence that soy is bad for you in any significant way.

::shrug:: My doc may be wrong. I’m passing on what he said, do what you want with the information.


Once again, just because something is “natural” does not make it healthy. Deadly nightshade “naturally” contains a decent dose of solanine, but I would no more eat that than I would eat beef that had been artifically injected with nasty synthetic solanine.

Most of the world’s most deadly toxins are entirely “natural”, but still anything synthetic or “chemical” (heh) gets a bad rap.

I should add that I’m not trying to imply that soya milk is harmful in any way, simply picking up on the “natural = good” myth.

In cases like these, you’ll almost always find studies that support both sides of the issue. The problem, if any, with soy products are the isoflavones and phytoestrogens and there is definitely conflicting information available about them. If you look at the reference studies in the article I linked, you’ll see that concern isn’t without merit. The Lancet article, for example, on the exposure of infants to phytoestrogens from soy based infant formula concluded that it shouldn’t be used without a compelling reason. Hardly a smoking gun against soy products, but not exactly an endorsement either. So in the end, you pretty much have to do your own risk/benefit analysis and decide for yourself. I have no compelling reason to eat soy products and I’m a bodybuilder concerned with testosterone levels, so I avoid them. However, if I’m at a friend’s house for dinner and she serves stir-fry with tofu, I eat it and don’t sweat it, so I’m not obsessive about it.

If you’re concerned about it, you can have your testosterone levels checked with a saliva test for under $50. At the amounts you drink and the length of time you’ve been drinking them, I would expect any effect to be measurable by now. Test your hormone levels now and if they’re low, lay off the Silk for a couple of months and then test again and found out for yourself what is going on in your body. You really don’t have to guess at it if you’re genuinely concerned.

AndroCHECK Saliva Collection Kit

Everyone’s body is different. In some people, supplementing with tribulus has no effect, however in my case, my testosterone was up by 30 points a month after I started taking it so my experience is that in most cases you simply have to experiment on yourself and see what happens.

There is a saying, “Do not discount the wisdom because of the wise.” I agree that Dr. Wong is a fringe kinda guy and I certainly wouldn’t accept anything he says as gospel just because he says it. But he does reference his sources and so if you are motivated, you can usually look at the source material and decide for yourself.

Crap. Anyone who lists sources on just one side of an issue and doesn’t even bother to mention the conflicting information is not a “kinda fringe” guy. He’s a charlatan pushing an agenda or just someone who’s getting kickbacks from pushing the sleaziest fake products along with his own snake oil.

I wouldn’t believe him if he said the sun would rise in the east tomorrow. I’ll bet he’s not a medical doctor either.

You can discount his wisdom all you want. Just don’t discount your payments to him or he’ll be all over your ass.

Like I said, he’s not. And his website is filled with wacky alternative nonsense - like some serum he recommends that somehow releases oxygen into your body tissues or how you need to make your body fluids more alkaline. It’s a bunch of crazy bullshit.

Sorry, of course you did. I had just come back from exploring his websites and being frustrated that he never gave his credentials, and I forgot what you said earlier in the thread.

Offering myself as anecdotal evidence, FWIW: I was vegan for 6 years, and literally lived on soy protein. I had Silk on my breakfast cereal every morning (and you’re right, the stuff is absolutely delicious, much better than cow milk). I lived on tofu, tempeh, and anything with soy in it for lunch and dinner. I dumped ground flaxseed plus flax oil all over my lunch and dinner. I also consumed every day vast amounts of flaxseed, which is high in phytoestrogens. When I began life as a transsexual, I increased my consumption of soy and flax, and added a couple of herbs (red clover and dang gui) for their phytoestrogens. For about 1 year, before I had a chance to start pharmaceutical estrogen, these four plants were my substitute.

Result? Practically nothing. The minimal amount of breast development I got during this time was so small that I can’t be sure the plants really had any effect at all.

I was so gung ho for phytoestrogen for a year’s time, if soy (plus everything else) was going to affect my body, it should have done more than that. So I think men who want to stay men should go ahead and pack in the soy, it doesn’t seem likely to make much difference either way. The thread I linked to has tons of scientific studies on phytoestrogen courtesy of Dr. Paprika.

After I saw an endocrinologist and started HRT, I went back to dairy because I didn’t want the weak estrogen in those plants to block my receptors from the real stuff, but Dr. Paprika thinks that won’t even make a difference.

Clarification: The phrase “pack it in” has a slang meaning “quit it.” I didn’t mean quit the soy, I meant gobble up all you like, it’s good nutrition.