In the 1990’s there was a growing consensus for studies that focus attention on women’s health.  This led to the development of the Women’s Health Initiative (WHI), the largest study ever performed to assess the risks and benefits of hormone replacement.  The study was very ambitious, also looking at the effects of Vitamin D and calcium and at the effects of diet. I will be focusing on the hormone arm of the study.  

You will see that this study looked at the harmful pharmaceutical versions of these hormones.  This is in contrast to bioidentical hormones, which are the human versions of estrogen and progesterone that play a role in the vitality and health of younger women. Furthermore, the results were misinterpreted by the media, presenting the results in the most negative light even though the less beneficial pharmaceutical hormones still had some benefit for many of the women.  These errors incorrectly misled women and the medical community about hormones such that there was a general chilling effect for any doctor to prescribe or any women to take hormones.  By misleading women and the medical community, the study has deprived women of the tremendous benefits of bioidentical hormones, resulting in inestimably more heart disease, more fatal hip fractures and increased prevalence of Alzheimer’s dementia.

First let’s look at the medications studied, Premarin and Provera.  Premarin, also known as conjugated equine estrogen, is derived from pregnant mares’ urine, hence the name Premarin.  While that may sound gross, the medical problem is that this version of estrogen is more potent than human estrogen, as equine estrogen has 10 different subtypes of estrogen.  This increased potency leads to increased risk of dislodging clots.  So if a woman has started clot formation as with early heart disease, there is increased risk of precipitating a heart attack or stroke when taking Premarin.  On the other hand, none of the many studies on bioidentical estradiol has ever been shown to cause dislodging of clots so there is no increased risk of heart attacks or strokes when taking estradiol.  In fact, when taking the bioidentical version of estradiol, women reduce their risk of heart disease by 2.5 times.  

The other medication studied, Provera, is the synthetic version of progesterone.  Progesterone is a key hormone for women that helps improve mood and sleep.  It also helps protect the breast and uterus by decreasing tissue proliferation.  However, Provera has mostly opposite effects.  Provera increases the risk of cancer and causes anxiety, depression and irritability.  So the WHI study looked at the effects of a medication that is known to have horrible side effects instead of studying a hormone that has so many positive benefits. 

Now let’s look at what was studied.  There were 3 groups.  One was given Premarin and Provera.  Another was given Premarin only.  These women had prior hysterectomies, so it was felt that Provera’s protective effects were not needed.  The 3rd group was given placebo corresponding to the two groups.  The main health parameters studied included heart disease, blood clots, cancer (breast, uterine, colorectal), diabetes, fractures and dementia. 

With regard to heart disease, women who started hormone replacement aged 50-55 had reduced incidence of heart disease while those above age 65 had increased incidence of heart disease, especially in the first year.  For those over 65 studied more than 5 years, the incidence of heart disease began to decline.  So what was happening?  The older women had started to develop clots and when taking Premarin, the clots were dislodged.  In subsequent years, they got the beneficial effects of estrogen on heart disease.  However, if given bioidentical estradiol, those clots would not have increased risk of dislodging.  They would get the cardiac benefits of estradiol without the risk of dislodging clots.  

Another interesting aspect was that for younger women, the heart benefits of estrogen were negated when they took Provera with Premarin.  Provera further generates clots, which increases heart disease.  Contrast this with progesterone, which works with estradiol in a synergistic way to protect against heart disease.  The lipid profile is improved with estradiol, decreasing the bad LDL cholesterol and increasing the good HDL cholesterol.  For every 1% increase of HDL, cardiac disease decreases by 3%.

Dementia was shown to be increased in the 65 and older age group in those who take Premarin.  However, other studies have shown significant decreases in Alzheimer’s when women start estradiol soon after reaching menopause.  So what is happening?  The older women starting Premarin are more likely to already have some calcifications in the arteries to their brains.  As a powerful estrogen, Premarin dislodges those calcifications causing small clots in their brains that lead to dementia.  However, the bioidentical version of estradiol does not dislodge these clots.  Thus, women who take estradiol get the brain benefits of estrogen without the risks of dislodging clots causing vascular dementia.

A common misconception is that estrogen causes breast cancer.  It is the number one concern I hear when I mention the great benefits of bioidentical hormones.  One positive of the WHI study is that it showed that women who took Premarin alone had no risk of increased breast cancer.  In fact, there was a slight decrease.  When adding Provera to Premarin the risk of breast cancer increased to 1.3 compared to 1 for placebo.  Remember, progesterone is protective against proliferation, so taking progesterone will not increase the risk of cancer.  Pharmaceutical Provera was shown to increase the risk, but bioidentical estrogen and progesterone do not increase the risk of breast cancer.

Lastly, across all ages and in all treated groups, estrogen was shown to reduce the incidence of hip fractures.  Osteoporosis is one of the leading killers of elderly women.  This is because the resulting hip fractures are debilitating with a high mortality rate.  The most common treatment for osteoporosis is anti-resorptive medication such as Fosamax.  Besides a challenging side effect profile, Fosamax does not increase bone density but slows its decline.  On the other hand, estradiol actually increases bone density, thereby significantly reducing the risk of hip fracture.

To summarize, the WHI study had a powerful chilling effect on women’s and physician’ attitudes toward hormone replacement.  This has deprived many women of the health benefits of hormone replacement, causing more incidence of all the diseases that bioidentical hormones help prevent. Don’t be misled by a study that studied pharmaceutical hormones.  Bioidentical hormones help prevent the 3 leading killers of elderly women: heart disease, osteoporosis and dementia.  At the same time, women who take bioidentical hormones will enjoy weight loss. improved libido and feel great energy.