R1- Lets keep this thread clean of personal dislikes and on topic.
What is your input on Soy Protein raising estrogen? I've read that the process of which soy protein is extracted uses alcohol, which depletes more than 98% of phyto-estrogen content.
"You know the fun thing about the soy protein debate is people only hear what they want to hear, yes soy protein contains phyto-estrogen base which does highly mimic the properties of human estrogen, but the strange thing is under low doses phyto estrogen actually attaches itself to human estrogen cells making the body believe there is more estrogen in the body so it actually lowers it's estrogen production to comphensate, yet phyto estrogen doesn't have all the catabolic properties as normal human estrogen."
It seems to be a torn discussion. There are studies proving both sides. I personally think it does not affect hormones to any measurable degree. Any insight on the subject is appreciated
Both sides of the argument so read carefully.
Three dietary intervention studies have reported the effects of soy or soy phytoestrogen consumption on reproductive hormones in men. Habito et al. (38) performed a randomized crossover study of 42 men with a mean age of 45.7 y who consumed 150 g lean meat or 290 g tofu (containing ∼70 mg isoflavones) daily for 4 wk. Blood concentrations of estradiol, testosterone, dihydrotestosterone and androstanediol glucuronide did not differ between the two diets. The mean testosterone-estradiol ratio was 10% lower (P = 0.05), SHBG was 9% higher (P = 0.01), and the free androgen index (total testosterone/SHBG × 100) was 7% lower (P = 0.06) after tofu consumption. This slight reduction in androgen activity was not confirmed by Nagata et al. (39), who reported a parallel-arm study of 34 men with a mean age of 32.4 y, one-half of whom consumed an average of 343 mL soymilk (containing ∼48 mg isoflavones) daily for 2 mo. Blood concentrations of estradiol, total and free testosterone, and SHBG did not differ between the two groups, although estrone concentrations tended to decrease in the group consuming soymilk. These results are generally consistent with those of Mitchell et al. (30), who found no changes in serum concentrations of estradiol, testosterone, follicle-stimulating hormone or luteinizing hormone in men consuming a tablet containing 40 mg/d of soy isoflavones.This is a part of an article i found:
IGF, Thyroid, and the Girly Hormones
It's fairly clear that soy protein lowers testosterone levels. How does it affect estrogen and progesterone levels? You'd figure that genistein would at least reduce the activity of estrogen to some extent, since it binds at the same receptor site, right? Well, apparently not. It turns out that genistein does not inhibit the effects of estradiol and in fact has been demonstrated to exert an additive effect when combined with estradiol.(2,8)
This means that they don't interfere with one another and can both exert the same negative effects at the same time, thus, packing a double punch. Furthermore, genistein may potentially increase estradiol levels as well. It's thought that this may occur because genistein may deconjugate estrone in the gut and allow for it to reabsorb into the bloostream and convert to estradiol.(9)
It's possible that it may also exert some progestational activity.(10) Even worse is that the estrogenic activity of these phytoestrogens may have been underestimated in the past, as there is evidence that they may be much more potent in vivo as opposed to in vitro [test tube] studies.(11) Oh, and while we're still on the topic or hormones, soy protein has also been shown to decrease IGF-1 concentrations in male rats.(12) Oh, and I'd feel bad if I forgot to mention that it can lower T4 levels, too.(13)There is a fair amount of info out there that shows no support for soy protein feminizing men or affecting men, but if nothing else, common sense should prevail. There are entire cultures that have soy-based diets that do not seem to be ridden with men w/ breasts or anything like that. There is evidence that isoflavones can have anti-estrogenic activity as well. This is not to mention the fact that many of the SPI's on the market (almost all of them are SPI, not SPC) do not contain isoflavones.