Fish oil is antiestrogenic in human studies

Fish oil is antiestrogenic in human studies
Test tube study: fish oil is anti-estrogenic

Extremely high doses of the fish fatty acid DHA may help protect the body from the impact of the female sex hormone estradiol. This is suggested by research done at the National Taiwan University, in which molecular scientists exposed human breast cancer cells to the fatty acid in test tubes. The experiment showed that DHA encourages cells to break down estradiol receptors.
The Taiwanese performed experiments because they were looking for an extra way to fight estradiol-sensitive cancers. Long-term treatment with the anti-estrogen Nolvadex makes some cells resistant. While the medicine does kick the estradiol-alpha receptors out of the cell’s nucleus, they manage to keep going outside. Because DHA – full name docosahexaenoic acid – inhibits cancer in many experiments, the researchers hoped that the fish fatty acid might possibly also play role. It might sound a little strange, but you never know your luck.

The longer the exposure, the more estradiol-alpha receptors were destroyed in the cell nucleus. The omega-6 fatty acid arachidonic acid enhanced the reduction of the number of estradiol receptors.
When the researchers repeated their experiment with the proteasome inhibitor (MG132) they detected no effect. See below.
The proteasome is a molecular shredder that cuts up wrong bits of proteins into small pieces. If you give the cells enough DHA, it appears they also clear up estradiol-alpha receptors.
Bodybuilders who experiment with high doses of fish fatty acids report that they become drier. This could have something to do with the effect the Taiwanese came across.
Fish fatty acids are interesting to bodybuilders for other reasons too. A diet that is rich in fish fatty acids raises the concentration of IGF-1 in the body, enhances fat burning and inhibits the growth of fat reserves. These effects have been shown in animal studies, test tube studies, experiments and human trials. Animal studies also suggest that fish-oil in the diet helps muscles to recover more quickly after training.


Source:
J Nutr Biochem. 2009 Apr 13. [Epub ahead of print].