Six weeks after a large clinical trial on estrogen therapy was abruptly terminated, scientists have published the first details of the study -- revealing that, on average, the hormone caused 12 more strokes and six additional venous blood clots per 10,000 women each year. Reporting in today's Journal of the American Medical Association, researchers for the Women's Health Initiative also reported that estrogen therapy for post-menopausal women did not provide protection against heart disease, as physicians once had hoped. Additionally -- in contrast to the effects of taking estrogen combined with a progestin -- the scientists found that estrogen on its own did not raise the risk of breast cancer nor lower the risk for colorectal cancer. Estrogen therapy did benefit women's bones, resulting in six fewer hip fractures each year. However, because of the stroke and blood clot risks, other bone-building options should be tried first, said Dr. Barbara Alving, director of the Women's Health Initiative and acting director of the National Heart, Lung, and Blood Institute. While it still makes sense, and is safe, to temporarily take hormones to relieve menopausal symptoms such as hot flashes, "these findings confirm that estrogen-alone therapy should not be used to prevent chronic disease," Alving said. The Food and Drug Administration recommends that hormones be taken for as short a time and in as low a dose as possible. The Women's Health Initiative is a large-scale investigation into the role of hormones, diet and vitamins on the health of women after menopause. One study of 16,608 women investigated the effects of taking estrogen with progestin. The study was halted several years early in 2002 after a safety monitoring board concluded that the increased risk of breast cancer, stroke, heart attacks and blood clots outweighed the benefits of taking the hormones. The estrogen-only study, in which the University of Pittsburgh Medical Center took part, involved 10,739 health women who had had hysterectomies. (Such women do not need to take a progestin, which is given to protect a woman's uterus against estrogen-induced cancers.) Scheduled to terminate in March 2005, it was also halted after the National Institutes of Health decided that women taking the hormone were being placed at a slight but unjustifiable risk. Women from both studies will be monitored for additional years. In addition, a study of estrogen's effects on dementia and memory will be published in upcoming months.

---

Copyright ©2025— Trib Total Media, LLC (TribLIVE.com)

---