It’s a striking claim often touted by celebrity doctors and health activists on social media. Taking hormone replacement therapy (HRT) to relieve menopausal symptoms, they say, also has “protective effects” on the brain and may reduce women’s risk of developing dementia.
TV presenter Davina McCall, whose father had Alzheimer’s, said in 2021, the year before his death, that she hoped hormone replacement therapy would give him “a little bit more protection” against the disease.
But the Lancet Commission, which for the first time analysed the best research on this topic, has thrown cold water on these claims.
There is even evidence that there may be a slightly increased risk of dementia for some people taking these middle-aged hormones, which typically involve a combination of estrogen and progesterone.
Dementia is more common in women than in men: almost two-thirds of those suffering from Alzheimer’s, for example, are women.
Stock image: Hormone replacement therapy, also known as HRT. The hormonal changes of menopause have been suggested as a possible reason for this, so HRT, which replenishes oestrogen and progesterone levels as they decline in middle age, has been suggested to be a protective factor.
It has been suggested that the hormonal changes of menopause may be a possible reason for this, and hormone replacement therapy (which replenishes estrogen and progesterone levels as they decline in middle age) has been suggested to have a protective effect.
But the studies assessed by the commission included one that found an increased risk of Alzheimer’s in women who took both oestrogen and progesterone for between five and nine years. The risk increased with increasing years of use – from 21 per cent for use of HRT for less than a year, to 74 per cent for use for more than 12 years.
A major analysis of 23 clinical trials reported that any form of hormone replacement therapy had a small but statistically significant negative effect on thinking and memory.
Fundamentally, no positive effect was found whether women used HRT for six months or for years. The negative impact was found to be even greater if a woman started taking HRT after the age of 60.
Another analysis of hundreds of trials found “high-quality evidence” that postmenopausal women should not take estrogen to prevent dementia because it may actually increase their risk.
Mature menopausal woman suffering from insomnia in bed at home
Advocates often dismiss such studies because some involve older forms of hormone replacement therapy that are no longer routinely used, including estrogen tablets, and say newer forms using gels and creams are safer.
But while the exact link between HRT and dementia remains unclear, the report’s lead author, Professor Gill Livingston of University College London, said: “We could not find any evidence that HRT reduces the risk of dementia.
‘While it is true that evidence that HRT can be harmful comes from older formulations, we do not yet have evidence that newer versions are protective.
“I understand that many people feel vastly different about hormone replacement therapy, but I’m afraid we have no evidence that it improves cognition.”