Women taking hormone replacement therapy following the menopause are not at a higher risk of developing dementia, a new study has found.

HRT, which is used to treat menopausal symptoms, including hot flushes, has previously been linked with memory deterioration and a doubling of the risk of developing dementia.

Researchers followed a group of more than 1,300 women between the ages of 50 and 55 who were on HRT medication known as conjugated equine oestrogens (CEOs).

The researchers, based at the Women’s Health Centre of Excellence for Research at Wake Forest School of Medicine in Winston-Salem, North Carolina, gave one set of women placebos and one the HRT treatment. The results were studied after seven years.

They found no overall differences in the brain function scores between women taking the HRT treatment and the placebos.

Dr Mark Espeland, a professor of biostatistics, led the research programme, and said it proved giving the hormones at an earlier age of the menopause provided more benefits than prescribing them at a later stage.

Dr Espeland said:

… Our findings provide reassurance that CEO-based therapies when administered to women earlier in the postmenopausal period do not seem to convey long-term adverse consequences for cognitive function.

The researchers did note some minor speech disturbances in some of the women taking CEOs longer-term. But they attributed that to ‘chance’ and reported that it was not statistically significant.

Around 1.5 million British women use HRT, which relives symptoms of the menopause including hot flushes and mood swings by replacing the body’s declining supply of the hormone oestrogen.

Previously, studies claimed the risk of suffering from mental decline could be doubled by taking hormone replacement therapy. A warning in 2003 was given by scientists in the United States who sought to determine if healthy women should turn to HRT to combat ill-health in later life, not just menopausal symptoms.

It is believed that fewer than 3 per cent of women in the UK aged 65 and over are on the therapy.

The research was published in the medical journal, JAMA Internal Medicine.