FORUMS > General Fitness Discussion Forum Rules

In the article on RealJock recently called Build Your Testorerone Naturally, Part 2, there are several conflicting comments by members about the use of soy products. Here are a couple of those comments:

hkdeven wrote:

Soy has no affect in the human production of testosterone or estrogen. The estrogen found in soy is known as plant estrogen and, as such, can only be processed by plants. Human estrogen and plant estrogen are entirely different.

masculineguynj wrote:
Actually soy has been proven to degenerate your body and your offsprings. Your children will have brain problems. Soy is a huge business in USA. You may be interested in the following articles:

http://www.mercola.com/article/soy/

http://www.soyonlineservice.co.nz/

http://www.ifrn.bbsrc.ac.uk/public/FoodInfoSheets/soya.html

Since I regularly use soy milk and other soy products I wonder if anyone out there has any definitive answers on this controversy. Specifically, I would like to know from a biochemist if the active structure on the plant estrogen referred to above is the same or similar to estrogen found in the human body, and if it is only similar could it still activate sites in the body that human estrogen acts upon or is it locked out because of its different molecular structure.

There is some cross-reactivity between the soy compounds and human estrogen receptors in vitro (in test tube experiments.) The number of experiments is small, and the relevance to in vivo processes (in the body) is unclear.

All plants synthesize toxins of one sort or another. Major crop plants have relatively few. It's probably not a concern unless a single plant dominates your diet.

What percentage of your daily calories come from soy?

I'm not a biochemist but in the last lecture I attended from Dr. Susan Kleiner (author of Power Eating, Powerfood Nutrition Plan and others) said that soy does not increase estrogen levels in the body (shooting down the musclehead who was arguing the contrary in the audience).

We don't know enough to have definitive answers but I know veg*ns depend on soy products for the convenience and protein, so it might be a good idea to limit these in your diet and seek out other options to ensure variety. Perhaps, if you want soy, just eat edamame instead of the overly processed foods? Have you read Vegetarian Sports Nutrition by D. Ennette Larson-Meyer?

I've seen all sorts of conflicting info on soy, and I've staked out a position for myself somewhere in the middle-ground between "soy is God's greatest contribution to human health!" and "soy is Satan in a bean pod!" Mostly, I just listen to what my body says, and what I've found is that soy just doesn't make me feel sated and truly nourished. So, I eat soy in small amounts, and I favor the fermented varieties (natto, tempeh, miso, tamari, and sufu.)

As for soy and testosterone, I did a quick sniff on PubMed and found this:

http://cebp.aacrjournals.org/cgi/content/full/16/4/829

Wow I am impressed! Kudos to paradox for an academic literature search!

paradox saidI've seen all sorts of conflicting info on soy, and I've staked out a position for myself somewhere in the middle-ground between "soy is God's greatest contribution to human health!" and "soy is Satan in a bean pod!" Mostly, I just listen to what my body says, and what I've found is that soy just doesn't make me feel sated and truly nourished. So, I eat soy in small amounts, and I favor the fermented varieties (natto, tempeh, miso, tamari, and sufu.)

As for soy and testosterone, I did a quick sniff on PubMed and found this:

http://cebp.aacrjournals.org/cgi/content/full/16/4/829

So then yeah, it looks like it can be an agonist for mammalian estrogen. Solution is take it in moderation (as with anything else)

mindgarden said
What percentage of your daily calories come from soy?

I have no idea but we are vegetarians so we cook a lot of meals using soy in different forms and I use soy milk with muesli type cereal before my workout.

Joshua876 saidHave you read Vegetarian Sports Nutrition by D. Ennette Larson-Meyer?

No but I will look into getting that from Amazon.

paradox said So, I eat soy in small amounts, and I favor the fermented varieties (natto, tempeh, miso, tamari, and sufu.)

As for soy and testosterone, I did a quick sniff on PubMed and found this:

http://cebp.aacrjournals.org/cgi/content/full/16/4/829

I read most of that article and it does seem to be the most authoritative and scientific of the articles I have read so thank you very much for that.

Why would the fermentation of soy make a difference in its affect on estrogen sites? How does that change the taste of soy which to my mind does not have much taste at all but takes on the flavour of what it is cooked with.

I thank all you guys above for your responses. I hope that by cutting my consumption of soy I will see a difference in my muscle mass. It does seem that at present I have to work so hard to get the slightest improvement, whereas, when I was younger and a meat eater, I was a lot bigger with a lot less work.

I had a friend who was quite concerned about Soy and about Dairy, and she went to Rice Milk. It was nice, basically sweeter than normal dairy. I'd certainly go for that if I became lactose intolerant or went vegan. (but I've never liked soy milk)

alexander7 saidWhy would the fermentation of soy make a difference in its affect on estrogen sites? How does that change the taste of soy which to my mind does not have much taste at all but takes on the flavour of what it is cooked with.

There's a claim that fermentation neutralizes certain "anti-nutrients" in soy, but I don't recall the exact details. I stick with fermented soy primarily because it is more interesting. Tempeh is pretty bland, but it has more flavor than tofu. Natto has a strong flavor, an extremely strong smell, and is slimier than boiled okra... I love the stuff. Tamari is soy sauce, and miso is basically soy sauce in paste form. Sufu (preserved bean curd) is fermented tofu, and it has a creamy texture and a taste reminiscent of strong blue cheese.

I had no idea that people were hating on soy. This was actually a really nice discovery. Thanks to all you smart ones out there keeping us informed!

paradox said

alexander7 saidWhy would the fermentation of soy make a difference in its affect on estrogen sites? How does that change the taste of soy which to my mind does not have much taste at all but takes on the flavour of what it is cooked with.

There's a claim that fermentation neutralizes certain "anti-nutrients" in soy, but I don't recall the exact details. I stick with fermented soy primarily because it is more interesting. Tempeh is pretty bland, but it has more flavor than tofu. Natto has a strong flavor, an extremely strong smell, and is slimier than boiled okra... I love the stuff. Tamari is soy sauce, and miso is basically soy sauce in paste form. Sufu (preserved bean curd) is fermented tofu, and it has a creamy texture and a taste reminiscent of strong blue cheese.

Thanks again! I have copied all this down and will look for these items in Torremolinos, ha, ha, sometimes a challenge in itself.

I have heard from a bio-chemist friend of mine who did a report on soy and production of soy. One of his strongest concerns was that most of the processing which is done in asia comes out with trace amounts of aluminum and this can cause birth defects and lots of other health issues. Maybe these studies we are reading not haven't carefully eliminated the other variables in there reports inorder to make a more interesting (eye catching subject) Has anyone else done any study in this area.

masculineone saidI have heard from a bio-chemist friend of mine who did a report on soy and production of soy. One of his strongest concerns was that most of the processing which is done in asia comes out with trace amounts of aluminum and this can cause birth defects and lots of other health issues. Maybe these studies we are reading not haven't carefully eliminated the other variables in there reports inorder to make a more interesting (eye catching subject) Has anyone else done any study in this area.

Wow, well if this is true, I would like to know more about it. Does your friend have a published study about these aluminum traces? If not, perhaps you can talk with your friend again and come up with something more authoritative on this subject.