Breast Cancer and Estrogen Dominance
The most serious consequence of estrogen dominance is breast cancer. Estrogen dominance could also be called progesterone deficiency, because it is the imbalance between estrogen and progesterone in a woman’s body that causes so many physical and emotional problems at midlife. A number of studies have found that insufficient progesterone may be a more important factor than excessive estrogen in increasing a woman’s risk of breast cancer.
One of the most significant studies of the relationship between low levels of natural progesterone and increased breast cancer risk was published in the American Journal of Epidemiology in August 1981. In this study, conducted by researchers from Johns Hopkins University’s School of Public Health, women of childbearing age who were having difficulty conceiving were divided into two groups. The first group consisted of women whose infertility was attributed to progesterone deficiency, while the second group was composed of women with infertility due to nonhormonal causes. All of the women were followed for thirteen to thirty-three years and the incidence of breast cancer in each group was recorded.
At the study’s conclusion, researchers found that the infertile women with progesterone deficiency had a premenopausal breast cancer risk that was 540 percent greater than that of women whose infertility was not related to their hormone status. Not only that, but these women had a 1,000 percent greater risk of death from all types of cancer. After menopause, when estrogen levels declined, the breast cancer risk was similar in the two groups, suggesting that progesterone’s protective effects were much more critical during the premenopausal period.
While I would not presume to suggest that progesterone is a cure for breast cancer, this study certainly supports the theory that it can help prevent it. Other research suggests that natural, bioidentical progesterone may delay the progression of this often deadly disease. Several studies have found that topical estrogen increases the rate of cellular division of breast epithelial cells, which are the cells that can become malignant. In contrast, topical progesterone slows down this cell division.
If you are wondering why so little has been written about natural, bioidentical hormones until recently, the answer is that for almost four decades counterfeit hormones were universally embraced by the medical profession as wonder drugs. The mainstream media reinforced this image, portraying counterfeit hormone replacement therapy (HRT) as a veritable fountain of youth. The counterfeit estrogens in particular were credited with seemingly magical powers to prevent age-related maladies as varied as osteoporosis and Alzheimer’s disease, colon cancer and heart disease. Negative studies, of which there were a growing number, were largely ignored by the media in favor of glowing reports that suggested female hormone replacement could enhance a woman’s quality of life and extend her years. But ignoring the negative studies didn’t make them go away. The Women’s Health Initiative changed all of that.
