Hormone replacement therapy may raise the risk of developing Alzheimer’s disease, a study has suggested, as experts said postmenopausal women should be warned of the possibility.
Researchers at the University of Helsinki looked at nearly 85,000 women with dementia and the same number who did not have the disease.
They found using HRT raised the risk of a diagnosis by up to 17%. .
Their study suggested that for every 10,000 women on HRT, up to 18 would develop Alzheimer’s each year who would not have been diagnosed had they not been on the therapy.
However, charities and the Royal College of GPs (RCGP) said the overall risk was very small and urged women not to be alarmed by the findings.
RCGP chairperson Prof Helen Stokes-Lampard said: “HRT can be of greatest benefit to many women who are suffering from some of the unpleasant side-effects of the menopause, such as hot flushes and night sweats.
“However, as with any medication, there are risks and it’s important that women are aware of them so that they can make an informed decision.
“To minimise any risk, best practice for most women is to prescribe the lowest possible dose of hormones for the shortest possible time.”
Each year, around 1.5 million women experience troubling post-menopausal symptoms and about 150,000 are prescribed HRT, which replaces oestrogen and progesterone.
While most experts believe it is a safe treatment, long-term use has been linked to a small increase in the risk of blood clots, breast and womb cancer.
Several previous studies have suggested that HRT could protect against Alzheimer’s disease, but a recent clinical trial failed to confirm an effect and implied an increased risk of dementia.
Commenting on the Finnish research, which was published in The BMJ, Dr Channa Jayasena, a consultant in reproductive endocrinology and andrology at Imperial College said: “Oestrogen has powerful effects on the brain. But I am surprised by the results of this study, since other studies have found that HRT actually improves cognitive function.
“The results of this study should not change the way HRT is prescribed or viewed.
“Even if HRT increased the future risk of Alzheimer’s, several years of treatment would be needed, and the effect is marginal.”
Alzheimer’s Society head of research Dr James Pickett added: “This increase [in risk] was so small it shouldn’t cause alarm or deter women from their prescribed treatment.” – The Daily Telegraph