Experts rule out link between HRT and dementia

There is “no evidence” that drugs commonly given to menopausal women can increase or slash the risk of dementia, according to researchers.

While more research is needed, experts claim the finding “reinforces current clinical guidance” around hormone therapy, and said the treatment should be prescribed “based on other perceived benefits and risks and not for dementia prevention”.

Hormone therapy, also known as hormone replacement therapy or HRT, replaces the hormones that decline during the menopause.

They help ease symptoms, which can include hot flushes, mood swings, sleep problems and night sweats.

The drugs can be taken as tablets, gels, sprays or creams, and can include different hormones, such as oestrogen, progesterone or sometimes testosterone.

A research team comprising experts from the UK, Ireland, Switzerland, Australia and China said it was “unclear” if HRT use affects dementia risk.

Their review comprised 10 studies including more than one million women.

The team looked at whether taking HRT or not impacted the risk of mild cognitive impairment (MCI), which causes problems with thinking and memory, or dementia in pre and post-menopausal women.

Patients included those with MCI, in early menopause and with premature ovarian insufficiency, which is when the ovaries stop working before the age of 40.

The study found “no significant association” between HRT and the risk of mild cognitive impairment or dementia.

The timing, duration or type of HRT also showed “no significant effects”.

Researchers said there was “no evidence that” using hormone therapy “either increases or decreases the risk of dementia in post-menopausal women” and that drugs should be prescribed “based on other perceived benefits and risks and not for dementia prevention”.

They also called for high-quality studies “to clarify the role” of hormone therapy and dementia risk, focusing on women who have early menopause or those with mild cognitive impairment.

It is estimated that about 982,000 people in the UK have dementia, around two thirds of which are women.

Melissa Melville, lead author of the study and PhD student at UCL psychology and language sciences, said: “Across the globe, dementia disproportionately affects women, even after accounting for women’s longer lifespans, so there’s a pressing need to understand what might be driving that risk, and to identify ways to reduce women’s risk of dementia.

“Menopause hormone therapy is widely used to manage menopausal symptoms, yet its impact on memory, cognition and dementia risk remains one of the most debated issues in women’s health.

“Conflicting research and concerns about potential harms have fuelled public and clinical debate, leaving women and clinicians unsure whether menopause hormone therapy might raise or reduce their risk of dementia.”

Researchers are now hopeful their findings, published in The Lancet Healthy Longevity, could “help to inform” upcoming guidelines from the World Health Organisation (WHO).

Professor Aimee Spector, of UCL psychology and language sciences, said: “Currently, the World Health Organisation provides no guidance on menopause hormone therapy and cognitive outcomes, leaving a critical gap for clinicians and policymakers.

“To cut through the noise, we reviewed the most rigorous research there is on the subject and found that menopause hormone therapy does not appear to impact dementia risk either positively or negatively.

“This review will help to inform the upcoming WHO guidelines on reducing the risk of cognitive decline and dementia, which are expected to be released in 2026.

“More high-quality, long-term research is still needed to fully understand the long-term impacts of menopausal hormone therapy.”

Reacting to the study, menopause specialist Louise Newson said: “It is impossible to state from this research that HRT does not either increase or reduce dementia risk.

“We have known for decades that our three hormones progesterone, estradiol and testosterone are made in our brains and have specific roles in our brains including improving the way the nerve cells grow, function and communicate with each other.

“Using common sense is important here in this debate. Many researchers seem to ignore that we prescribe hormones that are the same molecular structure as our own hormones – so completely different to old types of synthetic hormones.

“Women who are prescribed HRT, containing progesterone, estradiol and testosterone, have more benefits than risks and women who are prescribed hormones improve their symptoms – including memory problems – as well as their future health as there is good evidence with respect to reducing future risk of osteoporosis and heart disease.”