Curcumin is a mild anti-oestrogen
Curcumin, the main bioactive substance in turmeric, inhibits the production of estradiol. How the anti-oestrogenic effect of curcumin works the researchers at Hubei University of Medicine in China didn't look at, but that doesn't make their in-vitro study any less interesting.
Curcumin & testosterone
Curcumin [structural formula below] – in relatively high doses at least – has a testosterone boosting effect, and is therefore interesting for men and athletes who want to raise their testosterone level in a natural way. We wrote about this a few days ago.
This in itself is interesting of course, but the study that the Chinese published in the Iranian Journal of Reproductive Medicine shows that curcumin is even more interesting – even though the authors were interested in something totally different from longevity, men, anabolic hormones and sport. The Chinese were looking for a safe and cheap medicine for endometriosis.
Curcumin & estradiol
Endometriosis is a disease in which mucous membrane that normally lines the inside of the womb starts to grow outside the womb. The growth of this mucus membrane is regulated by estradiol [structural formula above], and it seems that the cells of the endometrial tissue outside the womb start to make estradiol themselves. It is known at least that women with endometriosis have raised levels of estradiol.
The Chinese researchers had previously discovered that curcumin inhibited the growth of endometrial cells in lab animals. [Int J Mol Med. 2011 Jan; 27(1): 87-94.] They wondered whether that was because curcumin has an anti-oestrogenic effect.
The Chinese first measured the concentration of estradiol in healthy endometrium cells and then in ectopic endometrial cells (i.e. outside the womb). And indeed, the estradiol concentration was higher in the latter.
The Chinese then exposed endometrial epithelial cells to curcumin in test tubes. The concentration of curcumin they used varied from 10 to 50 nanomoles per millilitre.
The figure below shows that curcumin reduced the concentration of estradiol [chemical structure above] in the cells compared with cells not exposed to curcumin.
The anti-oestrogenic effect of curcumin increased the longer the exposure lasted – and of course the higher the concentration of curcumin used. According to the researchers the anti-oestrogenic effect of curcumin only starts to become interesting above a concentration of 30 nanomoles/ml.
If you take supplements designed to boost the bioavailability of curcumin, then the concentration of curcumin in your blood should probably come pretty close to that of 30 nanomoles/ml.
Iran J Reprod Med. 2013 May;11(5):415-22.
Curcumin boosts testosterone level 27.03.2014