In 2002, the Women’s Health Initiative (WHI) completed a clinical trial on the effects of combination hormone therapy. This study led many people to fear that hormone therapy could cause breast cancer, stroke, and heart disease. Though some invaluable findings resulted from the tests, there were a number of important points that were not made widely known.
First, in the original study, a synthetic progesterone, called Provera, together with an estrogen derived from pregnant horse’s urine, called Premarin, were determined to be the main cause for concern. The combination, which was marketed together as Prempro, resulted in a 24 percent increase in risk for breast cancer and heart disease for the women who took the combined synthetic hormones.
The participants who were under 60 years of age during the trial and took only the estrogen showed no increased risk for either breast cancer or heart disease. In fact, after five years of estrogen-only therapy, the same women showed 61 percent less calcified plaque in the arteries—a common indicator of heart disease—than the women assigned to the placebo.
Secondly, it’s important to note, bio-identical hormones were not utilized in any of these clinical trials. No published study to date has indicated an increased risk between breast cancer or heart disease and bio-identical progesterone. On the contrary, studies have shown the opposite, with bio-identical testosterone having been shown to be brain, breast, bone, and heart protective.
Investigations into implantable, pellet-based testosterone therapy have measured a reduction in the rates of breast cancer occurrence, as well as increased protection from cancer. Twenty years after the studies began, there were no demonstrable increases in breast cancer risk and, even in the cases of breast cancer survivors, pellet-based bio-identical hormone replacement therapy did not show an increase in either cancer recurrence or death.
Contrary to the confusion and apprehension the WHI study initiated, the majority of researchers now recommend that men and women can and should take bio-identical hormones to safely and effectively treat symptoms stemming from menopause, perimenopause, and andropause.