The potential impact of estrogen on a woman’s health and wellbeing is enormous. While much attention has been given to the subject of hormone replacement, there has been very little discussion regarding the importance of estrogen metabolism, that is, how estrogen is broken down in the body. There is a growing body of evidence that shows it is not simply the total amount of estrogen in the body but how estrogen is metabolized that may play an important role in disease development. Regardless of the source; a woman’s own natural estrogen, hormone replacement, or xenoestrogens in the environment, how estrogen is broken down can be of critical importance in conditions such as cancer, heart disease, osteoporosis, and autoimmune disorders.
Estrogen is metabolized in the body along two major pathways and one minor. In one of the major pathways, estrogen is metabolized into 16 alpha-hydroxyestrone. This metabolite exerts a powerful stimulatory effect on target tissues, including the breast. Levels of 16 alpha-hydroxyestrone may increase in response to obesity, alcohol or toxic exposure. High levels of this potent metabolite are suggested to have significant estrogenic effects and may be associated with higher rates of breast cancer. The minor pathway for estrogen metabolism is 4-hydroxyestrone which may also enhance cancer development.
The other major pathway is 2-hydroxyestrone which breaks down estrogen into a much weaker metabolite with less stimulatory effects on target tissues. Therefore, if you metabolize estrogen primarily through the 2-hydroxyestrone pathway you may lower your risk of cellular damage and cancer.
A proper balance between 2-hydroxyestrone and 16 alpha-hydroxyestrone is critical to lowering the risk for estrogen dependent health problems.
So, what can you do to optimize estrogen metabolism? 
Moderate exercise, flaxseed, soy, kudzu, cruciferous vegetables (broccoli, cauliflower, brussels sprouts), and omega 3 fatty acids can all help to increase metabolism through the” good” or 2-hydroxyestrone pathway. The supplement, indole-3-carbinol, can also raise your good estrogen metabolite levels.
Have your doctor measure your urinary metabolites of 2-hydroxy and 16 alpha-hydroxyestrone. This assessment can be done in both premenopausal and postmenopausal women. Testing can assess the need for dietary and lifestyle changes as well as assess the impact of hormone replacement therapy.
By Dr. Linda Olafson, M.D., FAAFP from North Coast Integrative Medicine.