Women and Alzheimer’s disease: a story of gender inequality? : Domenico Pratico, MD, Temple Uni.
Updated: May 31
Nearly two-thirds of Americans with Alzheimer’s disease are women, and now there are questions about the validity of the long-held assumption that it’s because women tend to live longer than men. So, what else might put women at extra risk? Could it be genetics, biological differences in how women age, or lifestyle factors specific to women? Answering these questions could ultimately help find better treatments or preventative approaches.
Recent reports estimate that at age 65, women have a 1-in-6 chance of developing Alzheimer's disease during the rest of their lives, compared with a 1-in-11 chance for men. While age is the greatest risk factor for developing Alzheimer's disease, women, on average, live 4 to 5 years longer than men, and we know that Alzheimer's starts 20 years before diagnosis.
Once Alzheimer's disease is diagnosed, women tend to worsen faster than men, and scans show more rapid shrinkage of certain brain areas. Gene research offers some startling evidence on gender differences. Studies have analyzed records of more than 8,000 people for a form of DNA named apolipoprotein E-4 (apoE4), long known to increase Alzheimer's risk. Women who have a copy of apoE4 are about twice as likely to develop Alzheimer's disease as women without the gene, while men’s risk is only slightly increased.
What about hormones? That's been hard to establish so far. Years ago, a major study found that estrogen therapy after 65 might increase the risk of dementia, although later research showed hormone replacement around the onset of menopause was not a problem. Researchers are investigating whether menopause can be considered the tipping point that leaves certain women more vulnerable. Does menopause change the brain and the way it reacts to various factors? One possibility is that since estrogen can help regulate the brain's ability to produce energy, a reduction in estrogen levels could create a deficit in the fuel necessary for proper cognitive function.
Although the exact reason for this “medical inequality” is still unknown, the Alzheimer's research field has finally started to pay attention to this aspect of the disease risk by investing more and more in research.
Domenico Praticò, MD, is the Scott Richards North Star Charitable Foundation Chair for Alzheimer’s Research, Professor and Director of the Alzheimer’s Center at Temple, and Professor of Pharmacology at the Lewis Katz School of Medicine at Temple University