Older women taking hormone replacement therapy may have a lower risk of physical signs of Alzheimer disease in the brain, according to Stanford University research.
The study, reported by The Independent, found that women prescribed estrogen-only hormone replacement therapy had a lower probability of developing dementia. Patients who received this treatment were also less likely to experience memory loss or a decline in functional abilities.
Hormone replacement therapy is a medical treatment commonly prescribed to manage symptoms of menopause, such as hot flashes and mood changes, by replacing hormones like estrogen that naturally drop as women age. Alzheimer disease is a progressive neurological disorder that gradually impairs memory, cognitive function, and daily independence, making it the most common cause of dementia worldwide.
Dementia risk and cognitive decline
To evaluate the impact of hormone treatments, researchers analyzed data from two large national databases that track cases of Alzheimer disease. Using information from more than 20,000 women, the team discovered that using hormone therapy at an older age was linked to a significantly lower likelihood of receiving a clinical diagnosis of dementia.
Women who took the hormone medication had a 39 percent lower risk of a clinical dementia diagnosis compared to those who did not use the therapy. The study authors also noted that women on hormone replacement therapy were 33 percent less likely to display symptoms of memory loss and functional decline.
Dementia is an overarching term describing a range of symptoms affecting memory, reasoning, and social abilities severe enough to interfere with daily life. Clinical diagnoses typically rely on cognitive assessments, patient history, and brain imaging to identify functional impairment before structural brain changes become advanced.
Biological signs in brain tissue
The research team also examined post-mortem brain tissue data from 258 women who used hormone therapy during menopause and 2,701 women who did not. The post-mortem findings revealed that women who had taken hormone therapy had a 35 percent lower probability of showing biological markers of Alzheimer disease in the brain.
Among these biological indicators, researchers specifically noted a reduced accumulation of amyloid plaques in the brain tissue of women who received hormone treatment. Amyloid plaques are abnormal clusters of protein fragments that collect between nerve cells, impeding brain function and serving as one of the primary hallmark features of Alzheimer disease.
Stanford University is a leading research institution located in Stanford, California, known for its medical research programs. Database analysis allows scientists to track long-term health outcomes across large population groups, providing valuable statistical insights into potential preventive treatments.
Study limitations and related research
The study authors emphasized that the findings demonstrate an observational link rather than direct cause and effect. Because the research relied on existing database records, it cannot prove that hormone replacement therapy directly caused the reduction in dementia risk.
The report also referenced other recent findings on brain health, including a study showing that children who consumed less sugar before birth and during early childhood had a lower risk of dementia, Alzheimer disease, depression, and anxiety disorders later in adult life.
Additionally, a panel of 21 experts recently evaluated 80 potential treatments and vaccines for Alzheimer disease. The experts identified sildenafil, a medication marketed under the brand name Viagra, as a promising candidate for further investigation against the disease.
