HRT Prevents Alzheimer’s
It has taken too long, but finally tradiitonal medicine has concluded that hormone replacement therapy (HRT) prevents Alzheimer’s Disease. Timing is frequently the key to many things and that appears true even with HRT. If HRT is started within 5 years of a woman reaching menopause, their risk of Alzheimer’s disease can be reduced 32%.
But, if HRT is started at age 65 or later, the risk of Alzheimer’s may increase by 38%. A study presented at 150th Annual Meeting of the American Neurological Society was a meta-analysis of more than 50 clinical trials and observational studies with studies dating back to the 1990s when non-bioidentical hormones were the dominant form of HRT. The increased risk in those over age 65 was most noticeable in women who received non-bioidentical progestin. This suggests to us that the form of HRT may be more than the timing of initiating HRT.
The study involved 8,408,575 participants. The average age was 51 and the analysis looked at Alzheimer’s disease progression based on blood tests and brain imaging scans, studying the disease progression from initial mild cognitive impairment onward.
Estrogen helps the brain cells communicate with each other, calms inflammation, and protects against damage that can lead to Alzheimer’s disease. Only about 5% of the women are on HRT currently down from approximately 26% in 1999.
Women were scared off HRT following the Women’s Health Initiative Study of 2002 and 2004, which studied the effects of non-bioidentical hormones Premarin and Prempro.
Women’s Health Initiative
The Women’s Health Initiative was designed to be a two-armed primary prevention trial comparing estrogen alone (in the form of Premarin) and combined use of estrogen plus progesterone in the form of Premarin and medroxyprogesterone acetate (Provera) with placebo. The use of estrogen plus progesterone was in the form of a combination pill called Prempro. Outcomes looked at included the development of heart disease, breast cancer, stroke, pulmonary embolism, endometrial cancer, hip fracture, and death due to other causes.
The results of the first arm – combined estrogen (Premarin)/progesterone (Provera) in the form Prempro – were reported in 2002. Here is how the media reported those findings.
- 26% increase in breast cancer related to Prempro
- 29% increase in heart attacks related to Prempro
- 41% increase in strokes related to Prempro
Anyone who read that would have been concerned, and any woman on HRT would have been scared. But these percentages are misleading. If 2 out of 100 people get a heart attack. And, that number goes up to 3 out of a 100 people when placed on a drug, then that represents a 50% increase in heart attacks, even though the additional risk is actually only 1% (one more heart attack per hundred). Let’s take a closer look at the WHI numbers. Here’s how the study reported the numbers.
Outcomes were reported as cases per 10,000. The World Health Organization has designated/defined 10 cases or less per 10,000 as a rare event. Below in table form are the outcomes related to the use of Prempro found in the WHI Study.
WHI 2002 Findings: Prempro Versus Placebo (events per 10,000 patients)
| Outcome | Prempro versus Placebo |
| Breast cancer | 8 more cases |
| Heart attack | 7 more cases |
| Pulmonary embolism | 8 more cases |
| Stroke | 8 more cases |
| Colon cancer | 6 fewer cases |
| Hip fracture | 5 fewer cases |
Again, these are cases per 10,000 patients. So that’s a 0.08% and 0.07% increase in breast cancer and heart attacks, respectively – statistically significant but hardly clinically relevant. The overall additional risk in the Prempro arm was 19 events per 10,000 person-years or 0.19% additional risk.
Here are the results from the Premarin (estrogen) alone arm published in 2004.
WHI 2004 Findings: Premarin Versus Placebo (events per 10,000 patients)
| Outcome | Premarin versus Placebo |
| Breast cancer | 7 fewer cases |
| Heart attack | No effect |
| Pulmonary embolism | 12 more cases |
| Stroke | 6 more cases |
| Colon cancer | No effect |
| Hip fracture | 6 fewer cases |
The overall additional risk in the Premarin arm of the 2004 WHI Study was 2 events per 10,000 person-years or 0.02% additional risk. Interestingly, the decrease in breast cancer in the Premarin arm did not garner the same media attention as the increase in breast cancer in the Prempro arm even though the magnitude in change was similar.
When we look at the differences in heart attacks we can conclude that it is not estrogen (Premarin) at fault, but rather the progestin (Provera) that was in Prempro. Provera acts very differently in the body than the natural progesterone the body actually makes.
Nowadays, bioidentical hormones, which have identical structures to what the body naturally makes, are used far more often than at the time of the WHI Study.
