Postmenopausal women who initiate hormone replacement therapy (HRT) between the ages of 46 and 56 may experience a lower risk of developing dementia, according to findings from a recent study published in Alzheimer’s & Dementia. The research analyzed data from 183,450 postmenopausal women in the UK Biobank, with an average age of 60 at the start of the follow-up period.
Over a 13-year follow-up, HRT use was associated with an approximately 10% lower risk of all-cause dementia and a 16% lower risk of Alzheimer's disease. The association was most pronounced in women who began HRT between 46 and 56 years old and those who had undergone surgical menopause. Starting HRT after the age of 56 did not show a significant association with reduced dementia risk in this study.
Despite these associations, experts emphasize that this was an observational study and cannot establish a cause-and-effect relationship. Dr. Alexa Fiffick, a family medicine physician, noted that while the data is encouraging for certain patients, particularly those who experience menopause earlier or have a genetic predisposition to dementia, it does not definitively prove HRT prevents cognitive decline. She added that HRT does carry known risks and side effects, such as an increased risk of blood clots with oral estrogen, although this risk is not typically associated with transdermal options like patches or gels.
The study authors acknowledged limitations, including the inability to definitively conclude that HRT prevents dementia. They also noted that women using HRT might differ from non-users in ways that could influence dementia risk, such as overall health and lifestyle factors. The study lacked detailed information on the specific types, dosages, and administration methods of HRT used. Furthermore, the study population was predominantly of European ancestry and tended to be financially better off, which may limit the generalizability of the findings to other demographics.
While this study alone may not be sufficient to warrant seeking HRT solely for dementia prevention, Fiffick suggests that women experiencing menopausal symptoms should discuss their concerns with a healthcare provider. "If you're having symptoms, if you feel not yourself, come in, talk to your doctor, have that conversation," she advised. There is some existing data linking menopausal symptoms like hot flashes to vascular changes in the brain, and researchers are hopeful that treating these symptoms could potentially prevent vascular dementia, though more data is needed.
Future research, including randomized controlled trials, is planned by the study's researchers to further investigate the potential link between HRT and dementia risk. These trials aim to examine various factors such as different types of HRT, dosages, administration routes, treatment duration, age at initiation, and menopausal status. The goal is to provide women with more comprehensive data to make informed decisions about their health.