phytoestrogens both as preventive agents and whether dangerous for those with ER+ bc

[Lani]

technical but free access

Environ Health Perspect. 2008 Apr;116(4):426-33.

Phytoestrogens and breast cancer prevention: possible mechanisms of action.

Mense SM, Hei TK, Ganju RK, Bhat HK.
Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA.
OBJECTIVE: Phytoestrogens display an array of pharmacologic properties, and in recent years investigation of their potential as anticancer agents has increased dramatically. In this article we review the published literature related to phytoestrogens and breast cancer as well as suggest the possible mechanisms that may underlie the relationship between phytoestrogens and breast cancer. DATA SOURCES: Electronic searches on phytoestrogens and breast cancer were performed on MEDLINE and EMBASE in June 2007. No date restriction was placed on the electronic search. DATA EXTRACTION: We focused on experimental data from published studies that examined the characteristics of phytoestrogens using in vivo or in vitro models. We also include human intervention studies in this review. DATA SYNTHESIS: We evaluated evidence regarding the possible mechanisms of phytoestrogen action. Discussions of these mechanisms were organized into those activities related to the estrogen receptor, cell growth and proliferation, tumor development, signaling pathways, and estrogen-metabolizing enzymes. CONCLUSIONS: We suggest that despite numerous investigations, the mechanisms of phytoestrogen action in breast cancer have yet to be elucidated. It remains uncertain whether these plant compounds are chemoprotective or whether they may produce adverse outcomes related to breast carcinogenesis.
PMID: 18414622 [PubMed - in process
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

[TSund]

Lani,

This is a subject that's been on my mind quite a bit lately! I still wonder (despite all the discussion here) whether it's ever been proven that phytoestrogens feed ER+ bc . Is it possible they always do more good than harm if they are hooking up with receptors and therefore blocking the stronger forms of estrogen.

I have been reading about the 3 forms of estrogen, and my GP says the weakest form (estriol?) has even been shown to be helpful with certain bc's? To my limited knowledge that weakest form never been linked to bc despite the logic of that assumption. And if that is indeed true, it points to the phytoestrogens (weaker still) NOT harming bc status, possibly helping.

This is a huge issue in my mind, and I would welcome anyone who has seen definitive proof either way. It seems we are shooting ourselves in the foot on one side or the other of this argument and we better darn well get it straight.