Hormone replacement therapy linked to lower dementia risk in new study

A large observational study published in the journal Alzheimer’s & Dementia suggests that hormone replacement therapy (HRT) may be associated with a lower risk of developing dementia.

Analyzing data from over 183,000 postmenopausal women in the UK Biobank over an average of 13 years, researchers found that women using HRT for at least one year had approximately a 10% lower risk of all-cause dementia. The association was more pronounced for Alzheimer’s disease, showing a roughly 16% reduction in risk.

The protective benefits varied significantly based on specific factors. The strongest effects were observed in women who underwent surgical menopause (via hysterectomy or ovary removal), those with shorter natural estrogen exposure, and carriers of the APOE ε4 gene variant. Additionally, the association was most significant for women who initiated HRT between the ages of 46 and 56; starting the therapy after age 56 did not show a similar reduction in risk.

Researchers noted that because this was an observational study, it identifies associations rather than establishing a direct cause-and-effect relationship between HRT and dementia prevention. The study did not assess safety outcomes or adverse events.