For those taking Green Tea for weight loss, you might want to reconsider!
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"Green tea has compounds that block COMT. I stopped using as much green tea when I found that they were anti-androgenic. They not only block androgen at the receptor, thay also apear to downregulate androgen receptors.
Green tea is basically an anti-endocrine factor. It seems to reduce the effects of all steroid hormones. I don't mean to freak anybody out, it's just that the flavones (especially epigallocatechin gallate) are well known to reduce the actions of endogenous androgens (and estrogens) as well as even lowering testosterone levels themselves.
Anyway, my point is that, you may never see any significant effect of drinking green tea on muscle gains. Then again, we know that it is having an antagonistic effect, however small, in a direction opposite to what we want with respect to testosterone.
Cultures that consume a lot of green tea of also known to have fewer androgenic "manifestations" both normal (body hair, muscle mass, etc) as well as fewer pathologic manifestations (prostate problems, and other cancers associated with steroid hormones).
Fat is a different story. It clearly helps fat loss by altering catecholamine metabolism and probably a few other things."
--Bryan Haycock (creator of HST)
Full text at:
http://www.hypertrophy-specific.com/...t=ST;f=13;t=25
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03-13-2003, 02:10 PM #1
Green Tea lowers testosterone levels
Some people have a way with words. Other people not have way.
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03-13-2003, 02:25 PM #2
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03-13-2003, 04:22 PM #3
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03-13-2003, 04:46 PM #4
This stuff is so hard to put a definitive yes or no to IMHO... How much green tea does one need tp ingest to cause down regulation of the AR? Does anyone know? A parallel is that I am always bothered by people who think a little soy will cause massive estrogen related side effects. I am not convinced. I could be wrong though since Asians seem to be somewhat soft and have big tits by nature... The combination of soy and green tea has to be ruining them.
EDog
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03-13-2003, 06:05 PM #5
When you start talking hormones, it gets very complicated. Green tea has anti-androgenic properties yes, that's in fact why I take it; I want less DHT! By reducing the amount of T being converted to DHT, free T may be INCREASED by green tea! Asians suffer less androgen symptoms such as prostate cancer/baldness/etc because less of their T is converted to DHT... maybe. Jury's still out on that one. We need a lot more reliable and valid studies before we jump to conclusions.
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03-13-2003, 06:54 PM #6Originally posted by HiVol
When you start talking hormones, it gets very complicated. Green tea has anti-androgenic properties yes, that's in fact why I take it; I want less DHT! By reducing the amount of T being converted to DHT, free T may be INCREASED by green tea! Asians suffer less androgen symptoms such as prostate cancer/baldness/etc because less of their T is converted to DHT... maybe. Jury's still out on that one. We need a lot more reliable and valid studies before we jump to conclusions.Some people have a way with words. Other people not have way.
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03-13-2003, 07:00 PM #7
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03-13-2003, 07:06 PM #8Originally posted by dio
Green tea is also a 5ar inhibitor and aromatase inhibitor. I wouldn't worry about its effects on test levels.
Do you recommend drinking it in moderation or does it matter? Is it similar to the advice with soy? From what I hear about soy is under 50g per day its okay and could be benefitial to lower estrogen.Some people have a way with words. Other people not have way.
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03-13-2003, 07:17 PM #9
Inhibition of aromatase activity by green tea extract catechins and their endocrinological effects of oral administration in rats.
Satoh K, Sakamoto Y, Ogata A, Nagai F, Mikuriya H, Numazawa M, Yamada K, Aoki N.
Department of Toxicology, The Tokyo Metropolitan Research Laboratory of Public Health, 24-1 Hyakunincho 3 chome, Shinjuku-ku, Japan. sato@tokyo-eiken.go.jp
We orally administered polyphenone-60 (P-60), green tea extract catechins, in the diet (0, 1.25 and 5%) to male rats for 2, 4 and 8 weeks initiated at 5 weeks old. It was found that a 5% dose to male rats for 2-8 weeks induced goiters and decreased weights of the body, testis and prostate gland. Endocrinologically, elevating plasma thyroid stimulating hormone (TSH), luteinizing hormone (LH) and testosterone levels and decreasing tri-iodothyronine (T(3)) and thyroxine (T(4)) levels were induced by this treatment. We also found that P-60 as a whole and some of its constituents exhibited inhibitory effects on human placental aromatase activity by in vitro assay. The concentration of P-60 that required producing 50% inhibition of the aromatase activity (IC(50) value) was 28 microg/ml. The IC(50) values of (-)-catechin gallate (Cg), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCg) and (-)-gallocatechin gallate (GCg) were 5.5 x 10(-6), 1.0 x 10(-4), 6.0 x 10(-5) and 1.5 x 10(-5) M, respectively. (-)- Epicatechin gallate (ECg) at 1.0 x 10(-4) M produced 20% inhibition. (-)-Epicatechin (EC) and (+)-catechin (CT) exhibited no effects on aromatase activity. The endocrinological changes observed in vivo were in conformity with antithyroid effects and aromatase inhibition effects of P-60 and its constituents.
Structure-activity relationships for inhibition of human 5alpha-reductases by polyphenols.
Hiipakka RA, Zhang HZ, Dai W, Dai Q, Liao S.
Department of Biochemistry and Molecular Biology, The Ben May Institute for Cancer Research, and The Tang Center for Herbal Medicine Research MC6027, University of Chicago, 5841 S. Maryland, Chicago, IL 60637, USA.
The enzyme steroid 5 alpha-reductase (EC 1.3.99.5) catalyzes the NADPH-dependent reduction of the double bond of a variety of 3-oxo-Delta(4) steroids including the conversion of testosterone to 5 alpha-dihydrotestosterone. In humans, 5 alpha-reductase activity is critical for certain aspects of male sexual differentiation, and may be involved in the development of benign prostatic hyperplasia, alopecia, hirsutism, and prostate cancer. Certain natural products contain components that are inhibitors of 5 alpha-reductase, such as the green tea catechin (-)-epigallocatechin gallate (EGCG). EGCG shows potent inhibition in cell-free but not in whole-cell assays of 5 alpha-reductase. Replacement of the gallate ester in EGCG with long-chain fatty acids produced potent 5 alpha-reductase inhibitors that were active in both cell-free and whole-cell assay systems. Other flavonoids that were potent inhibitors of the type 1 5alpha-reductase include myricetin, quercitin, baicalein, and fisetin. Biochanin A, daidzein, genistein, and kaempferol were much better inhibitors of the type 2 than the type 1 isozyme. Several other natural and synthetic polyphenolic compounds were more effective inhibitors of the type 1 than the type 2 isozyme, including alizarin, anthrarobin, gossypol, nordihydroguaiaretic acid, caffeic acid phenethyl ester, and octyl and dodecyl gallates. The presence of a catechol group was characteristic of almost all inhibitors that showed selectivity for the type 1 isozyme of 5 alpha-reductase. Since some of these compounds are consumed as part of the normal diet or in supplements, they have the potential to inhibit 5 alpha-reductase activity, which may be useful for the prevention or treatment of androgen-dependent disorders. However, these compounds also may adversely affect male sexual differentiation.
Modulation of endocrine systems and food intake by green tea epigallocatechin gallate.
Kao YH, Hiipakka RA, Liao S.
Ben May Institute for Cancer Research, Department of Biochemistry and Molecular Biology, and Tang Center for Herbal Medicine Research, University of Chicago, Illinois 60637, USA.
Green tea polyphenols, especially the catechin, (-)-epigallocatechin gallate (EGCG), have been proposed as a cancer chemopreventative based on a variety of laboratory studies. For clear assessment of the possible physiological effects of green tea consumption, we injected pure green tea catechins ip into rats and studied their acute effects on endocrine systems. We found that EGCG, but not related catechins, significantly reduced food intake; body weight; blood levels of testosterone, estradiol, leptin, insulin, insulin-like growth factor I, LH, glucose, cholesterol, and triglyceride; as well as growth of the prostate, uterus, and ovary. Similar effects were observed in lean and obese male Zucker rats, suggesting that the effect of EGCG was independent of an intact leptin receptor. EGCG may interact specifically with a component of a leptin-independent appetite control pathway. Endocrine changes induced by parenteral administration of EGCG may relate to the observed growth inhibition and regression of human prostate and breast tumors in athymic mice treated with EGCG as well as play a role in the mechanism by which EGCG inhibits cancer initiation and promotion in various animal models of cancer.
Selective inhibition of steroid 5 alpha-reductase isozymes by tea epicatechin-3-gallate and epigallocatechin-3-gallate.
Liao S, Hiipakka RA.
Ben May Institute, University of Chicago, IL 60637, USA.
Inhibitors of 5 alpha-reductase may be effective in the treatment of 5 alpha-dihydrotestosterone-dependent abnormalities, such as benign prostate hyperplasia, prostate cancer and certain skin diseases. The green tea catechins, (-)epigallocatechin-3-gallate and (-)epicatechin-3-gallate, but not (-)epicatechin and (-)epigallocatechin, are potent inhibitors of type 1 but not type 2 5 alpha-reductase. (-)Epigallocatechin-3-gallate also inhibits accessory sex gland growth in the rat. These results suggest that certain tea gallates can regulate androgen action in target organs.
Soy phytochemicals and tea bioactive components synergistically inhibit androgen-sensitive human prostate tumors in mice.
Zhou JR, Yu L, Zhong Y, Blackburn GL.
Nutrition/Metabolism Laboratory, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. jrzhou@caregroup.harvard.edu
Although high doses of single bioactive agents may have potent anticancer effects, the chemopreventive properties of the Asian diet may result from interactions among several components that potentiate the activities of any single constituent. In Asia, where intake of soy products and tea consumption are very high, aggressive prostate cancer is significantly less prevalent in Asian men. The objective of the present study was to identify possible synergistic effects between soy and tea components on prostate tumor progression in a mouse model of orthotopic androgen-sensitive human prostate cancer. Soy phytochemical concentrate (SPC), black tea and green tea were compared with respect to tumorigenicity rate, primary tumor growth, tumor proliferation index and microvessel density, serum androgen level and metastases to lymph nodes. SPC, black tea and green tea significantly reduced tumorigenicity. SPC and black tea also significantly reduced final tumor weights. Green tea did not reduce final tumor weight, although it tended to elevate (P = 0.14) the serum dihydrotestosterone (DHT) concentration. The combination of SPC and black tea synergistically inhibited prostate tumorigenicity, final tumor weight and metastases to lymph nodes in vivo. The combination of SPC and green tea synergistically inhibited final tumor weight and metastasis and significantly reduced serum concentrations of both testosterone and DHT in vivo. Inhibition of tumor progression was associated with reduced tumor cell proliferation and tumor angiogenesis. This study suggests that further research is warranted to study the role of soy and tea combination as effective nutritional regimens in prostate cancer prevention.
Interesting stuff. I wonder how it compares to saw palmetto.
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03-13-2003, 07:37 PM #10
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03-15-2003, 06:26 AM #11
Re: Green Tea lowers testosterone levels
Originally posted by skinnyboy
For those taking Green Tea for weight loss, you might want to reconsider!
There is no solid data to support any of this. There are a few studes where they fed rats or injected rats with large amounts of EGCG and it lowered pretty much everything, including T. Green tea is a potent anti 5ar (which means it may reduce DHT) and the effect may also be organ specific. There are no in vivo human studies that show green tea lowers T. At high enough intakes, it might help reduce DHT, which in the adult male (not children!!!) that may be a good thing.
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"Green tea has compounds that block COMT. I stopped using as much green tea when I found that they were anti-androgenic. They not only block androgen at the receptor, thay also apear to downregulate androgen receptors.
Green tea is basically an anti-endocrine factor. It seems to reduce the effects of all steroid hormones. I don't mean to freak anybody out, it's just that the flavones (especially epigallocatechin gallate) are well known to reduce the actions of endogenous androgens (and estrogens) as well as even lowering testosterone levels themselves.
Anyway, my point is that, you may never see any significant effect of drinking green tea on muscle gains. Then again, we know that it is having an antagonistic effect, however small, in a direction opposite to what we want with respect to testosterone.
Cultures that consume a lot of green tea of also known to have fewer androgenic "manifestations" both normal (body hair, muscle mass, etc) as well as fewer pathologic manifestations (prostate problems, and other cancers associated with steroid hormones).
Fat is a different story. It clearly helps fat loss by altering catecholamine metabolism and probably a few other things."
--Bryan Haycock (creator of HST)
Full text at:
http://www.hypertrophy-specific.com/...t=ST;f=13;t=25BrinkZone, Where Bro-Science Got Rabies and Died!
www.BrinkZone.com
Check out my BrinkZone mini site on BB.com at:
www.bodybuilding.com/fun/willbrink.htm
=> President and Founder of Shaved head with goatee Crew
=> Science over bro science Crew
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03-15-2003, 09:14 AM #12Originally posted by EDog
since Asians seem to be somewhat soft and have big tits by nature... The combination of soy and green tea has to be ruining them.
EDog
EDog
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03-15-2003, 01:49 PM #13
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03-15-2003, 02:11 PM #14Originally posted by skinnyboy
So Will,
Any recommendations? 1-2 cups a day ok?BrinkZone, Where Bro-Science Got Rabies and Died!
www.BrinkZone.com
Check out my BrinkZone mini site on BB.com at:
www.bodybuilding.com/fun/willbrink.htm
=> President and Founder of Shaved head with goatee Crew
=> Science over bro science Crew
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03-16-2003, 04:18 PM #15
Re: Green Tea lowers testosterone levels
Originally posted by skinnyboy
For those taking Green Tea for weight loss, you might want to reconsider!
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Green tea is basically an anti-endocrine factor. It seems to reduce the effects of all steroid hormones. I don't mean to freak anybody out, it's just that the flavones (especially epigallocatechin gallate) are well known to reduce the actions of endogenous androgens (and estrogens) as well as even lowering testosterone levels themselves.
Epigallocatechin gallate is not even a flavone. And everything else he says here is pretty much just empty presumptions. Not even close to proof.
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03-16-2003, 04:20 PM #16
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03-16-2003, 04:21 PM #17Originally posted by EDog
This stuff is so hard to put a definitive yes or no to IMHO... How much green tea does one need tp ingest to cause down regulation of the AR?
EDog
Where is the evidence that it downregulates the androgen receptors EDOG? Do you know? Or are you just blindly accepting a statement that someone else read without question? C'mon!!!
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03-16-2003, 04:23 PM #18Originally posted by HiVol
When you start talking hormones, it gets very complicated. Green tea has anti-androgenic properties yes, that's in fact why I take it; I want less DHT!
Are you saying that EGCG is a 5alpha reductase inhibitor? You shouldn't use the term "anti-androgenic" if it indeed only inhibits DHT formation. "Anti-androgenic" usually denotes some sort of receptor antagonism
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03-16-2003, 04:26 PM #19Originally posted by dio
Green tea is also a 5ar inhibitor and aromatase inhibitor. I wouldn't worry about its effects on test levels.
It also will wash your car and do your taxes.
C'mon people. Practically anything can be shown to do anything in-vitro. If you research stuff enough you realize this.
Its only when this in-vitro research is validated by in-vivo data, at dosages and routes of administration that are practical, that you should get worried
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03-16-2003, 04:26 PM #20
Re: Re: Green Tea lowers testosterone levels
Originally posted by Patrick Arnold
Epigallocatechin gallate is not even a flavone. And everything else he says here is pretty much just empty presumptions. Not even close to proof.BrinkZone, Where Bro-Science Got Rabies and Died!
www.BrinkZone.com
Check out my BrinkZone mini site on BB.com at:
www.bodybuilding.com/fun/willbrink.htm
=> President and Founder of Shaved head with goatee Crew
=> Science over bro science Crew
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03-17-2003, 06:49 AM #21Originally posted by Patrick Arnold
It also will wash your car and do your taxes.
C'mon people. Practically anything can be shown to do anything in-vitro. If you research stuff enough you realize this.
Its only when this in-vitro research is validated by in-vivo data, at dosages and routes of administration that are practical, that you should get worried
Most of the studies Pogue posted above are not in vitro, but your point about specific dosages is still taken. Still, if we waited for conclusive evidence for everything we wouldn't move ahead on much. I'm sure you know this more than just about anybody.I saw the film, said that's the life for me
Forsake the mundane for some instability
So sue me.
Protect your right to buy the supplements you want: www.usfa.biz
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03-17-2003, 07:26 AM #22
Your all nuts. I love green tea Ive been drinking 1-2 cups a day for years. Does nothing but ramp me up for a workout and make me feel good (it has a component called theanine that is a natural relaxer). Green tea also has mega anti-oxident properties 20-100 times more potent than vitamin e and a. Thus preventing damage from free radicals.
Drink up
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03-21-2003, 07:22 PM #23
In the studies that green tea lowers T in rats, the scientist theorized could be due to the lower food consumption:
"These results may not have been a direct result of EGCG since food restriction could also cause these hormones to drop"
He goes on to state that one would have to constantly be drinking green tea to get these effects:
"Although oral administration of EGCG wasn't effective even after 14 consecutive days of large doses, Liao thinks that long term oral consumption may mimic some of the results obtained with injection.
"A person would have to drink green tea almost constantly to obtain these results," said Liao. "And since some of the hormonal changes we saw in the rats could have negative effects, especially in younger people, I don't recommend drinking large quantities of green tea for everybody. Much more research needs to be done"
http://www.uchospitals.edu/news/2000/20000223-tea.htmlSome people have a way with words. Other people not have way.
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03-22-2003, 11:03 PM #24
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07-05-2004, 03:50 PM #25Originally posted by dgtop
Your all nuts. I love green tea Ive been drinking 1-2 cups a day for years. Does nothing but ramp me up for a workout and make me feel good (it has a component called theanine that is a natural relaxer). Green tea also has mega anti-oxident properties 20-100 times more potent than vitamin e and a. Thus preventing damage from free radicals.
I love green tea (on his 5th year drinking it)-Syr
Knowledge is Power
syr2@cyber-rightsDOTnet
*People should be free to make decisions about their bodies. (R. Clapp)
*I don't always follow my own good advice. (milwood)
*The most important way to guarantee success in bodybuilding is to pick the right parents. (anonymous BBer)
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07-05-2004, 04:18 PM #26
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07-05-2004, 08:12 PM #27
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07-05-2004, 09:19 PM #28
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07-06-2004, 12:41 AM #29
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07-06-2004, 07:31 AM #30
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