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Posted By: stumpy_32
I don't want to start a "food fight" with you or anyone else on this site | ” |
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Good, we agree on not making this personal.
Back to nutrition. You state that soy "regulates" testosterone. Now, my numbers may be a bit high. Let's be fair and say that testosterone levels decrease only by 60%. I would still not call that a regulation. Males can benefit from normal-high levels of testosterone, especially trying to build muscle. Otherwise bodybuilders would have no reason to inject it. Therefore, soy directly decreases muscle building capacity.
On to the phytoestrogens. Unlike your source states, they are not "a weak form of estrogen that could have a drug-like effect in the body". The only things I could think of off the top of my head that
might match that description are xenoestrogens, which act more like prohormones, but we aren't talking about them. Phytoestrogens are not prohormones, which may or may not stimulate hormone productions, but the plant variation of estrogen which provides similar or identical effects. Which, in MALES, happen to be fat retention, less muscle build-up, and other sideeffects. Your source, when talking about cancer, also talks about breast cancer. Correct me if I'm wrong, but I thought breast cancer was a disease that only affects FEMALES, similar to prostate cancer in men. Also, I'd hazard a guess that you didn't read the article I posted. 'Cause this was kind of hard to miss:
1.Breinholt V, et al. "Estrogenic activity of flavonoids in mice. The importance of estrogen receptor distribution, metabolism and bioavailability." Food Chem Toxicol 2000 Jul;38(7):555-64
2.Casanova M, et al. "Developmental effects of dietary phytoestrogens in Sprague-Dawley rats and interactions of genistein and daidzein with rat estrogen receptors alpha and beta in vitro." Toxicol Sci 1999 Oct;51(2):236-44
3.Stahl S, et al. "Phytoestrogens act as estrogen agonists in an estrogen-responsive pituitary cell line." Toxicol Appl Pharmacol 1998 Sep;152(1):41-8
4.Zhong, et al. "Effects of dietary supplement of soy protein isolate and low fat diet on prostate cancer." FASEB J 2000;14(4):a531.11
5.Nagata C, et al. "Inverse association of soy product intake with serum androgen and estrogen concentrations in Japanese men." Nutr Cancer 2000;36(1):14-8.
6.Habito RC, et al. "Effects of replacing meat with soyabean in the diet on sex hormone concentrations in healthy adult males." Br J Nutr 2000 Oct;84(4):557-63
7.Strauss L, et al. "Genistein exerts estrogen-like effects in male mouse reproductive tract." Mol Cell Endocrinol 1998 Sep 25;144(1-2):83-93
8.Santell RC, et al. "Dietary genistein exerts estrogenic effects upon the uterus, mammary gland and the hypothalamic/pituitary axis in rats." J Nutr 1997 Feb;127(2):263-9
9.Harrison RM, et al. "Effect of genistein on steroid hormone production in the pregnant rhesus monkey." Proc Soc Exp Biol Med 1999 Oct;222(1):78-84
10.Zand RS, et al. "Steroid hormone activity of flavonoids and related compounds." Breast Cancer Res Treat 2000 Jul;62(1):35-49
11.Nagel SC, et al. "The effective free fraction of estradiol and xenoestrogens in human serum measured by whole cell uptake assays: physiology of delivery modifies estrogenic activity." Proc Soc Exp Biol Med 1998 Mar;217(3):300-9
12.Aukema HM, Housini I. "Dietary soy protein effects on disease and IGF-1 in male and female Han:SPDR-cy rats." Kidney Int 2001 Jan;59(1):52-61
13.Klein M, et al. "Energy metabolism and thyroid hormone levels of growing rats in response to different dietary proteins?soy or casein." Arch Tierernahr 2000;53(2):99-125.
14.Flynn KM, et al. "Effects of genistein exposure on sexually dimorphic behaviors in rats." Toxicol Sci 2000 Jun;55(2):311-9
15.Atanassova N, et al. "Comparative effects of neonatal exposure of male rats to potent and weak (environmental) estrogens on spermatogenesis at puberty and the relationship to adult testis size and fertility: evidence for stimulatory effects of low estrogen levels." Endocrinology 2000 Oct;141(10):3898-907
16.Whitten PL, et al. "Phytoestrogen influences on the development of behavior and gonadotropin function." Proc Soc Exp Biol Med 1995 Jan;208(1):82-6
17.Kumi-Diaka J, et al. "Cytotoxic potential of the phytochemical genistein isoflavone (4',5',7-trihydroxyisoflavone) and certain environmental chemical compounds on testicular cells." Biol Cell 1999 Sep;91(7):515-23
18.Ashton E, Ball M. "Effects of soy as tofu vs meat on lipoprotein concentrations." Eur J Clin Nutr 2000 Jan;54(1):14-9
19.Madani S, et al. "Dietary protein level and origin (casein and highly purified soybean protein) affect hepatic storage, plasma lipid transport, and antioxidative defense status in the rat." Nutrition 2000 May;16(5):368-75.
20.Risbridger G, et al. "Evidence that epithelial and mesenchymal estrogen receptor-alpha mediates effects of estrogen on prostatic epithelium." Dev Biol 2001 Jan 15;229(2):432-442
21.Schadereit R, et al. "Whole body protein turnover of growing rats in response to different dietary proteins?soy protein or casein." Arch Tierernahr 1999;52(4):311-21
22.Ji S, et al. "Soybean isoflavones, genistein and genistin, inhibit rat myoblast proliferation, fusion and myotube protein synthesis." J Nutr 1999 Jul;129(7):1291-7
23.Keung WM. "Dietary estrogenic isoflavones are potent inhibitors of beta-hydroxysteroid dehydrogenase of P. testosteronii." Biochem Biophys Res Commun 1995 Oct 24;215(3):1137-44
Doesn't get much more scientific than that. Again, soy may have benefits. But unless it turns me into some combination of Bill Gates, Hugh Hefner and Tom Cruise, I'm not risking those sideeffects.
And, very last comment: Yes, I did stereotype vegetarians rather severly. I do believe it is possible to be healthy and even build muscle on a vegetarian and maybe even vegan diet. However, most people who choose that path think they are living healthy just because they're not eating meat. That is not true. Getting enough protein, certain vitamins, and calories, especially on a vegan diet, requires an immense amount of planning. Most people do not think about that. So, in my opinion, a careless vegetarian is not living healthier than a careless non-vegetarian. However, both of us are biased in this view, so let's drop the meat versus no meat debate.
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