And here we are 10 years later. Countless women are suffering with hot flashes, vaginal dryness and insomnia with the belief, propagated by the media and many doctors, that they are putting themselves at huge risk if they take hormone therapy.
This belief was based on findings from the Women’s Health Initiative (WHI), a study that enrolled 27,000 women between 50 and 79 years of age to determine if postmenopausal estrogen therapy would decrease the risk of dying from cardiovascular disease.
Despite earlier studies that suggested otherwise, women in the WHI who used estrogen and progestin had a 28% increase in heart attacks, a 41% increase in stroke, and a 26% increase in breast cancer, and a more than two-fold increase in blood clots. No wonder women were flushing their hormones down the toilet.
Further analysis, however, revealed two significant flaws in the WHI study:
Flaw 1: The majority of the women were not newly menopausal, but were years beyond the onset of menopause. In fact, the average age of the women who participated in WHI was 63 -- and 70% of the women were over 60! When the data was later divided by age group, the results in younger women were much more reassuring. We now understand the concept of a critical window. If hormone therapy is started at the onset of menopause, the risks appeared to be much lower.
Flaw 2: All of the women in the WHI were given an oral estrogen. It seems that transdermal estrogens, such as patches, sprays and gels applied to the skin, are safer than estrogen taken by mouth. Among other things, transdermal estrogens are not metabolized by the liver and do not appear to increase the risk of blood clots that lead to stroke or heart attack.
For many years menopause experts have suspected that the data would have been very different if the study group was younger and used a different estrogen. But in the scientific community, it’s one thing to suspect something -- and it’s another thing to prove it.