Selenium is an essential trace mineral your body needs for normal thyroid function and other bodily processes. Plant foods supply the major dietary source of calcium in the U.S. and around the world, according to information from the Office of Dietary Supplements. Estrogen is a hormone produced by the human body, present in both men and women. Modern medicine also uses estrogen as a medication to treat certain health conditions including menopause. Blood levels of selenium have been associated with estrogen levels in women and show therapeutic promise to prevent and treat some cancers.
Cancer Prevention
Researchers from the Roswell Park Cancer Institute in New York recommend selenium breast cancer prevention trials in a report published in the April 2005 issue of “Cancer Research” after completing a clinical review of existing studies. Previous studies and case reports show selenium inhibits premalignant breast cell growth and tumor incidence after exposure to carcinogens. Estrogen stimulates breast cell growth in the body. The researchers also found evidence suggesting selenium effectively reduces incidences of colon, lung and prostate cancers.
Breast Cancer Therapy
A combination of selenium and endocrine therapy has potential as breast cancer therapy, according to Brian G. Rowan, Ph.D., an associate professor at Tulane University. According to his research, selenium “inhibits receptor function in breast cancer cells” and also reverses tamoxifen resistance in some people. Tamoxifen is hormonal drug therapy used in breast cancer. Rowan says scientists already understand how the two work together to produce this therapeutic effect.
Menstrual Cycle
Blood levels of selenium fluctuate during a woman’s menstrual cycle, according to a study from the Ohio State University and published in the February 2003 issue of the “Journal of the American College of Nutrition.” In the study, researchers measured the amount of estrogen and selenium in 14 women during their menstrual cycles. The women’s highest levels of blood selenium coincided with the estrogen peak, right before ovulation. Researchers found the change in selenium during the menstrual cycle significant enough to “be considered when assessing selenium status in patients.”
Estrogen Treatment
Estrogen levels may affect the amount of selenium in your body tissues, according to an animal study from the Ohio State University and published in the June 2011 issue of the “Journal of Nutritional Biochemistry.” In the study, female rats received oral doses of selenium and estrogen implants in their ovaries. The rats with higher doses of estrogen had increased selenium concentration in the liver, brain and plasma.
References
- “Journal of the American College of Nutrition"; Plasma Selenium and Plasma and Erythrocyte Glutathione Peroxidase Activity Increase with Estrogen during the Menstrual Cycle; E. J. Ha, et al.; February 2003
- “Journal of Nutritional Biochemistry"; Estrogen Status Alters Tissue Distribution and Metabolism of Selenium in Female Rats; X. Zhou, et al.; June 2011
- “Cancer Research"; Selenium Disrupts Estrogen Signaling by Altering Estrogen Receptor. Expression and Ligand Binding in Human Breast Cancer Cells; S.O. Lee, et al.; April 2005
- Tulane University; Selenium Regulation of Nuclear Receptors in Cancer; Brian G. Rowan
- Office of Dietary Supplements: Selenium
