A study of over 180,000 postmenopausal women in the UK suggests hormone replacement therapy may be associated with a reduced risk of developing dementia.

Researchers tracking 183,450 postmenopausal women in the UK have found that those who used hormone replacement therapy (HRT) were 10% less likely to develop dementia. The study, published in the journal Alzheimer’s & Dementia, also observed a 16% lower risk of Alzheimer’s disease among HRT users compared to those who had never used the therapy.

Study Findings and Methodology

The research, led by Prof Anne-Marie Minihane of the University of East Anglia, utilized data from the UK Biobank to track participants over an average of 13 years. During this period, nearly 4,000 cases of dementia were identified. The study focused on women who had used any form of HRT for at least one year.

Variations in Risk Reduction

The greatest benefit was observed in women who underwent surgical menopause, who showed a 26% lower risk of dementia. Women with naturally lower lifetime oestrogen exposure also saw a 16% reduction in risk. Additionally, the association between HRT and lower dementia risk appeared stronger in women carrying the Apoe4 gene variant.

Limitations and Expert Perspective

The researchers noted that the findings are based on observational data, meaning a causal link cannot be proven. Factors such as higher average education levels among HRT users may have influenced the results. Experts, including Dr. Susan Kohlhaas of Alzheimer’s Research UK, emphasized that the study does not confirm HRT should be used specifically to reduce dementia risk and advised patients to consult their GPs.