SOY at last... yes or no ?

[Vítor Rage]

I´ve done a lot of research but there is no end point about the benefits of soy protein for bodybuilders. So much differents opinions on soy amino acids qualities , isoflavones, estronic or antiestrogenic proprieties, and so on.
What is your real opinion of soy use for bodybuilders?

 

[musketeer]

I only take one hit of soy a day just before bed. It is one last shake of protein in milk and should take 3-4 hours to slowly digest. Don't know ablout the flavones. This seems to be working though.

 

[Greek Freak]

I think its good to have many different types of protein although I personally try to avoid it. Search for some posts about soy in the diet board by anthrax, he had a couple good ones.

 

[Dr.M]

I think most recent research says that soy is crap due to the way its processed, but I'm not a scientist so who knows which studies you can trust, some say yay some say nay.

 

[Mike P.T.]

Too much soy is not good for bodybuilding purposes. It is detrimental because it has been shown in studies to mimic estrogen in the body.

 

[Canuck4]

Soy sucks.

 

[Sigmund Roid]

Soy can fuck up your thyroid:

http://thyroid.about.com/library/weekly/aa041202a.htm

Ok, the article is a bit hysterical, but a few scoops of soy protein powder is very concentrated, and worse than eating a small piece of whale snot (tofu).

 

[Sigmund Roid]

Goitrogenic and estrogenic activity of soy isoflavones.

Doerge DR, Sheehan DM.

Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, Arkansas, USA.

Soy is known to produce estrogenic isoflavones. Here, we briefly review the evidence for binding of isoflavones to the estrogen receptor, in vivo estrogenicity and developmental toxicity, and estrogen developmental carcinogenesis in rats. Genistein, the major soy isoflavone, also has a frank estrogenic effect in women. We then focus on evidence from animal and human studies suggesting a link between soy consumption and goiter, an activity independent of estrogenicity. Iodine deficiency greatly increases soy antithyroid effects, whereas iodine supplementation is protective. Thus, soy effects on the thyroid involve the critical relationship between iodine status and thyroid function. In rats consuming genistein-fortified diets, genistein was measured in the thyroid at levels that produced dose-dependent and significant inactivation of rat and human thyroid peroxidase (TPO) in vitro. Furthermore, rat TPO activity was dose-dependently reduced by up to 80%. Although these effects are clear and reproducible, other measures of thyroid function in vivo (serum levels of triiodothyronine, thyroxine, and thyroid-stimulating hormone; thyroid weight; and thyroid histopathology) were all normal. Additional factors appear necessary for soy to cause overt thyroid toxicity. These clearly include iodine deficiency but may also include additional soy components, other defects of hormone synthesis, or additional goitrogenic dietary factors. Although safety testing of natural products, including soy products, is not required, the possibility that widely consumed soy products may cause harm in the human population via either or both estrogenic and goitrogenic activities is of concern. Rigorous, high-quality experimental and human research into soy toxicity is the best way to address these concerns. Similar studies in wildlife populations are also appropriate.

 

[Dr.M]

Most of the big boom behind Soy a few years ago was once again, industry $ponsored.