Menopause hormonal therapy found linked to Alzheimer’s risk

Older women who take menopausal hormone therapy may be at a higher risk of Alzheimer’s.

A study published in Science Advances on Wednesday found faster accumulation of tau proteins – implicated in Alzheimer’s – in the brains of women over 70 who had taken the hormone therapy a decade earlier.

The demand is growing for the hormone therapy to counteract debilitating menopausal symptoms, which can last in some women for around eight years. “A quarter of currently postmenopausal women who are 70 years and older have a history of hormone therapy use and have now entered a critical age of risk for Alzheimer’s disease,” Rachel Buckley, senior author of the study from the Massachusetts General Hospital in the US, said.

The study compared brain imaging scans of 73 women who had taken hormone therapy an average of 14 years before to those of 73 age-matched women who had not.

The participants were aged 51 to 89 at the start of the study and underwent PET scans for the beta amyloid brain protein over a mean period of 4.5 years and for tau over 3.5 years.

“In older women – aged over 70 years – hormone therapy users exhibited faster regional tau accumulation relative to non-users,” the study found. The tau accumulation was prominent in brain regions such as the entorhinal cortex, which is involved in memory, navigation and time perception, and the fusiform gyri, involved in memory of faces and bodies.

These brain regions are “areas of known vulnerability” in preclinical Alzheirmer’s patients.

Researchers said that menopausal hormonal therapy in older women could indirectly affect cognitive decline via regional tau protein accumulation.

“Together, these observational findings suggest that in older women, HT use predicts pathological progression of tau with implications for cognitive decline, even when HT use was reported more than a decade after the first PET scan,” they wrote, referring to the therapy.

In women under 70, however, hormone therapy “associations with tau accumulation were negligible”.

Researchers said they hoped the findings could help in optimising menopausal treatment guidelines.