ex_banana-eater said,
[b said:
Quote[/b] ] "Significantly reduced food intake, bodyweight". Those are the reasons why Green Tea lowered the hormones.
You are right that reducing caloric intake or drastically altering macronutrient ratios in the diet can effect hormone levels.
However, my comments on the effects of green tea on androgen activity were based on a wider aray of research on the subject.
1) Hiipakka RA, Zhang HZ, Dai W, Dai Q, Liao S. Structure-activity relationships for inhibition of human 5alpha-reductases by polyphenols. Biochem Pharmacol. 2002 Mar 15;63(6):1165-76.
“Since some of these compounds [EGCG and others] 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.”
2) Liao S. The medicinal action of androgens and green tea epigallocatechin gallate. Hong Kong Med J. 2001 Dec;7(4):369-74.
“It is now clear that a specific green tea catechin, (-)epigallocatechin-3-gallate, can modulate the production and biological actions of androgens and other hormones.
Modulation of androgenic activity and administration of (-)epigallocatechin-3-gallate may be useful for the treatment of various hormone-related abnormalities, such as benign prostatic hyperplasia, baldness, and acne, as well as androgen-dependent and -independent prostate cancers.”
3) Ren F, Zhang S, Mitchell SH, Butler R, Young CY. Tea polyphenols down-regulate the expression of the androgen receptor in LNCaP prostate cancer cells. Oncogene. 2000 Apr 6;19(15):1924-32.
“In conclusion, we have described a new property of tea polyphenols that inhibits
androgen action by
repressing the transcription of the androgen receptor gene.”
4) Liao S, Hiipakka RA. Selective inhibition of steroid 5 alpha-reductase isozymes by tea
epicatechin-3-gallate and epigallocatechin-3-gallate. Biochem Biophys Res Commun. 1995 Sep 25;214(3):833-8.
“(-)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.”
And from the study you referred to…
5) Kao YH, Hiipakka RA, Liao S Modulation of endocrine systems and food intake by green tea epigallocatechin gallate. Endocrinology. 2000 Mar;141(3):980-7.
“The effect of EGCG on the weight of male accessory sexual organs was due to lowered circulating levels of testosterone. This conclusion is supported by the following observations. 1) Androgens such as TP and DHTP blocked the effect of EGCG on the weight of accessory sexual organs, including prostates. 2) EGCG did not reduce prostate weight in androgen-supplemented castrated Sprague Dawley rats (our unpublished observations). 3) EGCG-induced weight loss of prostate and other androgen-sensitive organs was accompanied by an EGCG-induced lowering of serum testosterone.”
Continuing…
“
Also, by lowering plasma levels of sex steroids and other endocrine factors, such as IGF-I, long term use of EGCG or green tea may be effective in the prevention and suppression of the growth of hormone-dependent and -independent prostate and breast cancer (14, 34, 35). This may relate to the low occurrence of breast and prostate cancer metastasis and mortality in some Asian countries (14, 36) where green tea is consumed regularly. Despite many potential benefits of green tea and EGCG consumption, it is also important to evaluate undesirable health-related consequences that may arise from EGCG- induced reductions in the levels of sex steroid hormones and other endocrine factors.”
ex_banana-eater said,
[b said:
Quote[/b] ] BTW Characterizing the Asian race.. good one.
It is difficult to know for sure the meaning behind this comment. From the tone it sounds as if you feel my comments about cultures who consume a lot of green tea and the different physical characteristics they might exhibit as
racist. I feel the idea that diet may effect physical developement and disease rates is a reasonable hypothesis and is in line with epidemiological perspectives on hormone related disease rates as it relates to diet, including the study you referenced, and I quote, "Also, by lowering plasma levels of sex steroids and other endocrine factors, such as IGF-I, long term use of EGCG or green tea may be effective in the prevention and suppression of the growth of hormone-dependent and -independent prostate and breast cancer (14, 34, 35).
This may relate to the low occurrence of breast and prostate cancer metastasis and mortality in some Asian countries (14, 36) where green tea is consumed regularly.". Niether mine, nor the comments of these researchers has anything to do with socio/political racism, nevertheless, I apologize to anyone who, being unfamiliar with epidemiological perspectives on culture and physiology, might have misinterpreted it.
