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A new study by researchers at Mass General Brigham has found that women over 70 who took menopausal hormone therapy (HT) more than a decade earlier showed faster accumulation of tau, a key protein linked to Alzheimer’s disease.
The findings, published in Science Advances, could help doctors and patients better understand the potential risks of HT and its impact on brain health.
Researchers analyzed brain scans from 146 women, split into two groups: 73 women who had used HT (on average, 14 years prior) and 73 women who had never used HT.
The women were between the ages of 51 and 89 at the start of the study.
Over several years, the team tracked the accumulation of amyloid beta (a protein associated with Alzheimer’s) and tau (another protein strongly linked to brain decline in Alzheimer’s).
The researchers did not find major differences in amyloid beta levels between the two groups. However, they did find that women over 70 who had previously used HT had a significantly faster buildup of tau in specific brain regionscompared to those who had never used HT. This pattern was not observed in women under 70.
Why This Matters
Alzheimer’s disease is more common in women, and hormones like estrogen are believed to play a role in brain aging. Around one in four women over 70 has used hormone therapy at some point. These findings suggest that starting HT at an older age or delaying its use for too long may increase Alzheimer’s risk by speeding up tau accumulation.
Rachel F. Buckley, Ph.D., a senior author of the study, explains:
“Our findings add to the evidence that delaying initiation of hormone therapy, especially in older women, could lead to worse Alzheimer’s outcomes.”
Current clinical guidelines recommend starting HT within 10 years of menopause to minimize risks. The researchers note that they cannot say for certain whether the faster tau buildup is due to aging itself or past prescribing practices that delayed HT use for some women.
However, their data suggest that the timing of HT could influence tau accumulation and, potentially, cognitive decline.
What This Means for Women’s Health
The study does not conclude that all hormone therapy leads to Alzheimer’s but suggests that when a woman starts HT could make a difference. Women considering HT should have informed discussions with their doctors about potential benefits and risks, especially regarding brain health and Alzheimer’s risk.
First author Gillian T. Coughlan, Ph.D., emphasizes the study’s importance:
“We hope that our research will help inform discussions about Alzheimer’s risk, reproductive health, and treatment decisions for women.”
More research is needed to fully understand the relationship between HT, tau buildup, and cognitive decline. However, this study adds to growing evidence that the timing of hormone therapy use may play a critical role in long-term brain health.
The research findings can be found in Science Advances.
If you care about Alzheimer’s disease, please read studies about the protective power of dietary antioxidants against Alzheimer’s, and eating habits linked to higher Alzheimer’s risk.
For more health information, please see recent studies that oral cannabis extract may help reduce Alzheimer’s symptoms, and Vitamin E may help prevent Parkinson’s disease.
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