Women who receive estrogen therapy for menopausal symptoms could have lower risk of developing dementia than those who do not, report researchers from Stanford and Johns Hopkins University School of Medicine.
The researchers found that women who used estrogen therapy were about 35% less likely to display severe Alzheimer’s damage in their brain tissue after death compared with non-users and had a 39% lower likelihood of a dementia diagnosis while living.
“More than two-thirds of patients with Alzheimer’s disease are women, which has led to increased interest in the neurophysiologic impact of estrogen decline during menopause. Estrogen decline is postulated to affect multiple physiologic processes relevant to brain aging, including neuronal synaptic plasticity, neuroinflammation, and blood-brain barrier integrity,” explain the investigators in the journal Neurology.
“Although early evidence suggested that menopausal hormone therapy may be protective against dementia, more recent studies have found inconclusive or even harmful effects.”
To try and assess the impact of estrogen therapy, the researchers analyzed data from two large U.S. health databases covering over 20,000 women aged 50 and older, the National Alzheimer’s Coordinating Center (NACC) and Alzheimer’s Disease Neuroimaging Initiative (ADNI). The impact of combined hormone therapy was not assessed.
Overall, the study included post-mortem data from 258 women in the NACC group who were prescribed estrogen therapy and 2,701 who were not. The team also included molecular imaging and fluid biomarker data from 110 estrogen users and 1,948 non-users from the ADNI. For both studies the researchers had approximately three to five years of follow-up data and the women who used estrogen therapy were aged 70 years or older when they began taking the hormone.
In addition to having a lower chance of having postmortem signs of Alzheimer’s disease or being diagnosed with the condition during their lifetime, the researchers also report lower levels of amyloid pathology in women who took estrogen therapy. They also had a 41% lower chance of having small strokes and blood vessel damage in the brain than non-users.
While the results are interesting, the researchers say more work is needed before providing specific dementia prevention therapy suggestions to older women.
“This study looked back at women who were using hormone therapy decades ago with the timing and type of use differing from what is current practice for most women today, so the results are informative, but they may not apply to today’s standards,” said co-lead author Jennifer Bruno, PhD, a researcher at Stanford, in a press statement.
“Despite these limitations, our findings provide evidence of an association between use of estrogen-only hormone therapy during later life and better outcomes on dementia and brain health.”
