Estrogen from pregnant mares'urine is used for hormone replacement therapy. Bad reports on HRT have cut the number of mares needed in half. Their colts were never kept. (Louise McCoy/The Epoch Times)
But then some evidence started to emerge that linked HRT with an increased risk of heart disease. And other evidence linked HRT with an increased risk of certain cancers, notably breast cancer.
The real turning point for HRT came around 2002, on the publication of a study that identified the risks of HRT quite clearly. In fact, the trial was stopped early because of the risks women were being subjected to by being on HRT—not just an increased risk of heart disease and breast cancer but also an increased risk of stroke and pulmonary embolism (from blood clots that form in the legs and travel to the lungs) [1].
The results of this study are thought to be a major factor in the steady decline in the prescription of HRT (and the concomitant decline in breast cancer rates in post-menopausal women).
Not everyone has been so keen to desert this sinking ship. Some have suggested that HRT really is beneficial; it just has to be started early enough. The idea here is that starting HRT nice and early means treating women with low levels of atherosclerosis (the underlying pathological process in heart disease), whereas later treatment in women with more advanced disease is going to be too late or even make matters worse.
So, while the disadvantages of HRT do generally seem to outweigh the advantages, it has been suggested that if treatment is started early enough, it’s the other way round. It’s a neat theory, but is there any evidence for it?
Reading the British Medical Journal recently I was made aware of a recent study that examined this hypothesis. The authors of this study reassessed data from the women who took part in the seminal 2002 study. Principally, they assessed data regarding the long-term health of these women and the timing of HRT.
One of the findings of this study is that starting HRT early was associated with an increased risk of breast cancer and an increased risk of cancer overall.
Early HRT was also associated with an increased risk of “venous thromboembolism” (for example, pulmonary embolism) and stroke, but a reduced risk of fracture of the hip.
The authors conclude, “These analyses provide little support for the hypothesis of favorable effects among women who initiate postmenopausal estrogen use soon after menopause, either for coronary heart disease or for health benefits versus risk indices considered.”
An accompanying commentary [3] summarizes the effect of early treatment with HRT thus:
• Either it has no effect on coronary heart disease risk, or makes it worse compared to later treatment.
• It increases stroke and venous thrombosis risk (just like later treatment).
• It may pose even greater risks with regard to breast cancer.
They conclude that the data does “not support the hypothesis of favorable effects in women starting hormone therapy soon after menopause.” Whether it’s started early or late, the evidence suggests that HRT does more harm than good.
References:
1. Rossouw JE, et al. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women’s Health Initiative randomized controlled trial. JAMA 2002; 288(3): 321–33
2. Prentice RL, et al. Benefits and Risks of Postmenopausal Hormone Therapy When It Is Initiated Soon After Menopause. American Journal of Epidemiology 25 May 2009 [Epub ahead of print publication]
3. Banks E, et al. Invited Commentary: Hormone Therapy Risks and Benefits—The Women’s Health Initiative Findings and the Postmenopausal Estrogen Timing Hypothesis. American Journal Epidemiology 25 May 2009 [Epub ahead of print publication]
Dr. John Briffa is a London-based physician and health writer with an interest in nutrition and natural medicine. His Web site is drbriffa.com
