Does soy protein raise estrogen levels? Lets end the debate right now.

[Bouncer]

So I saw a diet that a local "diet guru" had given given to my buddy getting ready for a show.

In the diet he recommends soy protein (2 scoops) in the morning and again at night.

Can some explain the idea behind this? I had always heard soy should be avoided for men because it raises estrogen levels? Is this true or false?

All thoughts, opinions, and study's are welcome.

[Bouncer]

From the link that rado posted.

Myth: Soy foods contain estrogen compounds that may cause hormonal disturbances.

The isoflavones found in soy foods are sometimes called phytoestrogens (plant-estrogens) because they have a chemical structure similar to the hormone estrogen. Also, isoflavones can bind to estrogen receptors and exert some estrogen-like effects in cells.18, 19

That said, isoflavones are actually quite different from estrogen. Estrogen-like effects are rarely observed in clinical studies measuring the ingestion of soy foods or isoflavones.20-22

This is not surprising since receptor binding – a common in vitro measure of estrogenicity – is a poor predictor of in vivo activity.23

Compounds that bind to estrogen receptors often have different, and sometimes opposite, physiological effects depending upon how the isoflavone and receptor interact within different cells.24-26

Clinical studies do show that neither soy foods nor isoflavones affect serum levels of testosterone or estrogen.27-39 In fact, several studies have found no effects on testosterone despite ingestion of isoflavones at levels that were 20- to 30-times higher than the typical Japanese intake.40, 41

No hormone-related abnormalities, such as thelarche or precocious puberty, have been ascribed to soy formula use in infants.

[Bouncer]

still not clear though. can soy protein powder give you gyno or not?

[Bouncer]

Well Soy does increase estrogen levels...Just not sure if it would be enough to do that bro...I mean come on, think about it...A lot of people do drink Soy products...We would have a bunch more tits running around than we do now.

any increase in estrogen levels is a bad thing.

so its conclusive then, soy raises estrogen?

[liftsiron]

Soy is shit: On paper the amino acid profile looks good looks but in the body only about 40-45% of the protein is digestible. Soy disrupts thyroid function and hormonal balance.


Soy foods contain trypsin inhibitors that inhibit protein digestion and affect pancreatic function. In test animals, diets high in trypsin inhibitors led to stunted growth and pancreatic disorders. Soy foods increase the body’s requirement for vitamin D, needed for strong bones and normal growth. Phytic acid in soy foods results in reduced bioavailabilty of iron and zinc which are required for the health and development of the brain and nervous system. Soy also lacks cholesterol, likewise essential for the development of the brain and nervous system. Megadoses of phytoestrogens in soy formula have been implicated in the current trend toward increasingly premature sexual development in girls and delayed or retarded sexual development in boys.

Soy isoflavones are phyto-endocrine disrupters. At dietary levels, they can prevent ovulation and may stimulate the growth of cancer cells. Eating as little as 30 grams (about 4 tablespoons) of soy per day can result in hypothyroidism with symptoms of lethargy, constipation, weight gain and fatigue.

Soy foods may stimulate the growth of estrogen-dependent tumors and cause thyroid problems. Low thyroid function is associated with difficulties in menopause.

Numerous animal studies show that soy foods cause infertility in animals. Soy consumption enhances hair growth in middle-aged men, indicating lowered testosterone levels. Japanese housewives feed tofu to their husbands frequently when they want to reduce his virility.

source: Soy on line

Soy can also mimic and potentate the effects of estrogen:

Interaction of Estrogenic Chemicals and Phytoestrogens with Estrogen Receptor ß
George G. J. M. Kuiper1, Josephine G. Lemmen, Bo Carlsson, J. Christopher Corton, Stephen H. Safe, Paul T. van der Saag, Bart van der Burg2 and Jan-Åke Gustafsson3

Center for Biotechnology and Department of Medical Nutrition (G.G.J.M.K., J.-Å.G.), Karolinska Institute and KaroBio AB (B.C.) Huddinge, Sweden; Hubrecht Laboratory, Netherlands Institute for Developmental Biology (B.v.d.B., P.T.v.d.S., J.G.L.) Utrecht, The Netherlands; Chemical Industry Institute of Toxicology (J.C.C.), Research Triangle Park, North Carolina; Department of Veterinary Physiology and Pharmacology (S.H.S.), Texas A&M University, College Station, Texas 77843-4466

Address all correspondence and requests for reprints to: Dr. George Kuiper, Center for Biotechnology, NOVUM, S-14186 Huddinge, Sweden. E-mail: [email protected].

The rat, mouse and human estrogen receptor (ER) exists as two subtypes, ER{alpha} and ERß, which differ in the C-terminal ligand-binding domain and in the N-terminal transactivation domain. In this study, we investigated the estrogenic activity of environmental chemicals and phytoestrogens in competition binding assays with ER{alpha} or ERß protein, and in a transient gene expression assay using cells in which an acute estrogenic response is created by cotransfecting cultures with recombinant human ER{alpha} or ERß complementary DNA (cDNA) in the presence of an estrogen-dependent reporter plasmid.

Saturation ligand-binding analysis of human ER{alpha} and ERß protein revealed a single binding component for [3H]-17ß-estradiol (E2) with high affinity [dissociation constant (Kd) = 0.05 - 0.1 nM]. All environmental estrogenic chemicals [polychlorinated hydroxybiphenyls, dichlorodiphenyltrichloroethane (DDT) and derivatives, alkylphenols, bisphenol A, methoxychlor and chlordecone] compete with E2 for binding to both ER subtypes with a similar preference and degree. In most instances the relative binding affinities (RBA) are at least 1000-fold lower than that of E2. Some phytoestrogens such as coumestrol, genistein, apigenin, naringenin, and kaempferol compete stronger with E2 for binding to ERß than to ER{alpha}. Estrogenic chemicals, as for instance nonylphenol, bisphenol A, o, p'-DDT and 2',4',6'-trichloro-4-biphenylol stimulate the transcriptional activity of ER{alpha} and ERß at concentrations of 100-1000 nM. Phytoestrogens, including genistein, coumestrol and zearalenone stimulate the transcriptional activity of both ER subtypes at concentrations of 1–10 nM. The ranking of the estrogenic potency of phytoestrogens for both ER subtypes in the transactivation assay is different; that is, E2 >> zearalenone = coumestrol > genistein > daidzein > apigenin = phloretin > biochanin A = kaempferol = naringenin > formononetin = ipriflavone = quercetin = chrysin for ER{alpha} and E2 >> genistein = coumestrol > zearalenone > daidzein > biochanin A = apigenin = kaempferol = naringenin > phloretin = quercetin = ipriflavone = formononetin = chrysin for ERß. Antiestrogenic activity of the phytoestrogens could not be detected, except for zearalenone which is a full agonist for ER{alpha} and a mixed agonist-antagonist for ERß. In summary, while the estrogenic potency of industrial-derived estrogenic chemicals is very limited, the estrogenic potency of phytoestrogens is significant, especially for ERß, and they may trigger many of the biological responses that are evoked by the physiological estrogens.




This article has been cited by other articles:


Home page
EndocrinologyHome page
B. R. Bhavnani, S.-P. Tam, and X. Lu
Structure Activity Relationships and Differential Interactions and Functional Activity of Various Equine Estrogens Mediated via Estrogen Receptors (ERs) ER{alpha} and ER{beta}
Endocrinology, October 1, 2008; 149(10): 4857 - 4870.
[Abstract] [Full Text] [PDF]
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[Bouncer]

question.

Asian women eat a shit load of soy. and yet statistically they have the lowest rate of breast cancer. since breast cancer almost always has it connection with estrogen something seems wrong here. why would someone who eats soy in large quantities have a lower chance of breast cancer?

[liftsiron]

They could have a genetic resilience to breast cancer and/or are less exposed to other contributing factor. Asian women do however have the highest rate of thyriod dysfunction, which has been liked to soy.

question.

Asian women eat a shit load of soy. and yet statistically they have the lowest rate of breast cancer. since breast cancer almost always has it connection with estrogen something seems wrong here. why would someone who eats soy in large quantities have a lower chance of breast cancer?

[wnabeabeast]

question.

Asian women eat a shit load of soy. and yet statistically they have the lowest rate of breast cancer. since breast cancer almost always has it connection with estrogen something seems wrong here. why would someone who eats soy in large quantities have a lower chance of breast cancer?

I think and this is only my opinion...it could be like GH, if u r prone to have tumors it might speed up the growth of the tumor so I don't know if this is the right way of saying but if u pre disposition to have breast cancer soy might speed it up.

[decadecadeca]

I would say the genetic makeup of Asian women in combination with the rest of their dietary habits, environmental impacts and other factors would all play a part in their lower reported rates of breast cancer.

I don't think they can point to one issue such as soy and declare conclusively that it alone is the cause.

[Mr I]

Liftsiron are you a pharmacist? you gets hold of some good shit in the way of studies etc

[Bouncer]

so does it have any benefit then? why the hell would this guys suggest soy to my buddy.

[decadecadeca]

I think the bottom line for me isn't "Why not use soy?" but rather "Why use soy?".

It isn't cheaper, isn't more effective, isn't more readily available, isn't easier to digest, etc....and it MIGHT in fact have negative side effects.

So why bother?

[Mr I]

I think and this is only my opinion...it could be like GH, if u r prone to have tumors it might speed up the growth of the tumor so I don't know if this is the right way of saying but if u pre disposition to have breast cancer soy might speed it up.

I agree with this fro what I've read generally, once there is a cancer and if it is an estrogen dependent carcinoma (cancer covers a range of cell mutations) and if so thats the time to cain the nolvadex and aromasin etc but having a high estrogen level doesn't itself cause the onset of cancer or else every teenage girl would have it and every woman past menaupause would be immune

[blm]

I think the bottom line for me isn't "Why not use soy?" but rather "Why use soy?".

It isn't cheaper, isn't more effective, isn't more readily available, isn't easier to digest, etc....and it MIGHT in fact have negative side effects.

So why bother?

Seems logical to me.

[liftsiron]

I agree with this fro what I've read generally, once there is a cancer and if it is an estrogen dependent carcinoma (cancer covers a range of cell mutations) and if so thats the time to cain the nolvadex and aromasin etc but having a high estrogen level doesn't itself cause the onset of cancer or else every teenage girl would have it and every woman past menaupause would be immune

Exactly!!!!