Estrogen Metabolism and Breast Cancer Prevention

Excessive estrogen stimulation probably increases risk of breast cancer.  This is partly due to the body's transforming normal estrogen into estrogen-derived molecules that are also carcinogenic. The good news is that estrogen metabolism has a choice of several main pathways. Two of these yield cancer-promoting products.  However, one metabolic path does not promote cancer, and might actually suppress it.

Each woman’s estrogen metabolism is different, so that the balance between the pro- and anti-cancer pathways varies.  A simple morning urine test has recently become available that can measure how much of an individual woman’s estrogen goes down each path.  About half of women tested tend toward the pro-cancer pathway.  Future breast cancer risk seems to depend in part on this balance.

Fortunately, it’s usually fairly easy to shift a woman’s estrogen metabolism away from the pro-cancer paths over to the anti-cancer one.  At least two different vegetable extracts are able to do this for the large majority of women.  These are Indole-3-carbinol (I-3-C) and Diindolylmethane (DIM).

I3C and DIM are found in broccoli, cauliflower, brussels sprouts and other vegetables.  Eating these foods is also protective.  However, for optimal results, you have to eat quite a lot–about two pounds of greens each day.  So for practical purposes, taking I-3-C or DIM makes sense if your estrogen metabolism leans toward the pro-cancer pathways.  

Other dietary components can help estrogen metabolism, including  omega-3 polyunsaturated fatty acids (fatty fish) and lignans in foods like flax seed.  The moral:  Our genetic metabolism is not everything.  High risk profiles can often be modified by appropriate nutritional/metabolic actions.