HRT could protect the brain from Parkinson’s, says study

OESTROGEN may protect the brain against neurodegenerative diseases such as Parkinson’s and dementia, and women should not be discouraged from taking hormone replacement therapy (HRT), scientists have said.

A study by the Mayo Clinic in the US has found surgical removal of both ovaries to be associated with a five-fold increased risk of Parkinson’s Disease in pre-menopausal women under 43.

Researchers say one explanation may be that the loss of oestrogen, or another ovarian hormone, accelerates biological ageing in the brain.

The study, published in medical journal Jama Network Open, estimates that for every 53 women who have had both ovaries removed, one will go on to develop Parkinson’s Disease.

Previous research by the team has shown that ovary removal can also double a woman’s risk of dementia in old age, with the risk getting worse the earlier the operation is carried out.

The research suggests oestrogen may be having a protective effect on the brain and that, as levels decline, supplementation could be beneficial. Dr Walter Rocca, who led the research said: “The protective effects may be against vascular or degenerative processes. For example, it has been hypothesised that oestrogen may reduce the accumulation of amyloid in the brain.”

Many women have been concerned about, or have been discouraged from, taking HRT over fears it could actually increase their risk of dementia. A case control study in Finland found those taking HRT had a 9 to 17 per cent higher risk of developing Alzheimer’s.

However, Mayo Clinic researchers found HRT has no adverse effects on memory, and may even be beneficial.

Dr Stephanie Faubion, director of the Mayo’s Center for Women’s Health, said: “Having women understand that hormone therapy will not increase their risk of dementia when used early in the menopause transition is important.”

Scientists now believe that the sharp decline in oestrogen during menopause reshapes the brain. New York’s Weill Cornell Medical College and the University of Arizona recently found it causes reductions in grey matter and changes in blood flow. They believe giving HRT early could stave off such brain changes before they become irreversible.