Bioidentical Hormones – Research Update

The pros and cons of hormone replacement therapy (HRT) for perimenopausal and menopausal women have been hotly debated for many years. As a naturopathic physician, I’ve helped women navigate the choppy waters of menopause for over two decades. I believe that hormone management should be very individualized and I  generally recommend lifestyle first, natural medicines second, and pharmaceuticals third, if possible. I recently completed a course that analyzed the research on HRT over the last 20 years. When you look carefully at the research, there is a role for hormone replacement therapy to help manage symptoms of perimenopause and menopause safely and effectively and to serve as a preventative medicine. 

First, some history. HRT was used for 70 years before the Women’s Health Initiative (WHI) did the first large placebo-controlled study in 2002. This groundbreaking study sounded alarms regarding increased breast cancer risk in women who took Premarin (estrogen) and Provera (synthetic progesterone).  In addition, they found a higher rate of blood clots, potentially leading to strokes and more, so many women were unprescribed HRT as a result. 

Subsequent analysis determined that the study had major flaws. The average age of the women starting estrogen therapy was 65. We now understand there is a critical window for starting hormone therapy to maximize the benefits and reduce the risks, which is within ten years of one’s menopause, or under 60. 

Second, the estrogen used in the experiment was extracted from pregnant mares’ urine and contained non-human estrogens. Now, most prescriptions written use a bioidentical estrogen called estradiol or E2. It is processed much differently in the body and has fewer risks. The progesterone used was a synthetic cousin of our progesterone called progestin, which comes with many more side effects. Third, the route of administration of estrogen matters. Yes, taking oral pills of estrogen does increase blood clotting, especially in women over 60. However, using a patch or cream on the skin does not do so in any significant way. We’ve come a long way from 2002 to understand how to use these hormones safely. 

According to the esteemed North American Menopause Society, estrogen has strong evidence showing it helps with hot flashes and night sweats. They say it can be used for women of any age in low doses locally for genital and urinary symptoms and to improve sexual function. Systemic estrogen also helps to prevent bone loss and fracture associated with osteoporosis. The research shows this benefit is most relevant if estrogen is started within five years of menopause and the benefit is lost after ceasing the estrogen therapy. Topical estrogen therapy can slightly reduce cardiovascular disease risk but only if started early.  

The most interesting evidence regarding estrogen replacement therapy is around reducing cognitive decline. One in three people develop a significant cognitive decline in their lifetime, and ⅔ of the people with Alzheimer’s are women. Estrogen has many protective effects on the brain, including increasing neuronal growth and repair, increasing neuroplasticity, decreasing the build-up of tau proteins and amyloid plaques (associated with Alzheimer’s), and much more. Estrogen therapy seems to help slow cognitive decline, not reverse it. One study showed that women who started estrogen at 75 years old had a worse rate of decline. So, yes, there is a critical window for starting estrogen. Women who have their ovaries removed or have very early menopause may especially benefit from starting estrogen therapy right away. 

Evidence shows that estrogen may help somewhat with joint pain, muscle weakness, sleep issues, depression, skin aging, dry eyes, hearing loss, and diabetes. But what about breast cancer? Well, after years of analysis of the WHI study, it has been shown that when they started giving horse estrogens and synthetic progestin to women far older than the critical age window in oral vs. transdermal doses, after three years, an increase of less than one case of breast cancer over the placebo rate per 1,000 women per year could be attributed to the hormones. That risk is less than the increased risk of breast cancer associated with drinking two glasses of wine a day, and the same as the risk of being obese or inactive. In women who took only estrogen (women who’d had a hysterectomy), there was a slight decrease in breast cancer rate vs. placebo. Three French studies showed that when bioidentical estrogen is used with women in a better age window and coupled with bioidentical progesterone, there was no increase in breast cancer rates.  

HRT isn’t for everyone, so discuss it with a conventional or naturopathic doctor up to date on the latest research analysis to see if you would be a suitable candidate and what to expect. For people without extended health insurance, compounding pharmacies can make up HRT prescriptions for about ⅓ to ½ the cost of pharmaceutical suppliers—tell your naturopathic or conventional doctor your preference.  Another advantage of compounded bioidentical hormones is various delivery methods can be used depending on the desired effects and preference of the patient. Transdermal absorption of hormones has been well established in scientific research. So the bottom line is that bioidentical estrogen with bioidentical progesterone can have a role to play not only in the management of symptoms of menopause but also in the enhancement of the ageing process.