A new study, involving researchers in Galway, has found early menopause is associated with an increased risk of dementia.
The findings follow an analysis of the experiences of 1,329 women, to examine the association between reproductive factors and how the brain ages.
The research found that entering menopause at an earlier age appeared to be associated with an increased risk of dementia, while post-menopause Hormone Replacement Therapy (HRT) appeared to be linked to a lower risk of dementia.
Professor Emer McGrath, of the College of Medicine at the University of Galway, was one of the lead authors of today's report.
She outlined how researchers first gathered data on the age at the time of a woman’s first period; the age at onset of menopause; the duration of a woman’s reproductive lifespan; levels of oestrogen in the blood; and whether a woman used post-menopausal hormone replacement therapy.
These factors were then related to performance on neurocognitive testing, signs of brain shrinkage on MRI scans and a woman’s future risk of developing dementia.
Greater exposure to oestrogen over the reproductive lifespan was associated with enhanced cognitive performance and larger brain volumes.
Women who had more children, or who were older at the time of menopause, were also associated with better cognitive test performance.
Professor McGrath said an exploration of ageing on MRI brain scans found "having more children was associated with larger brain volumes, including in the areas we tend to see shrinkage in Alzheimer’s disease".
The study aims to increase understanding in relation to sex related differences when it comes to Alzheimer’s disease and related dementias.
Women have a higher risk of dementia compared to men, and account for almost two thirds of those living with Alzheimer’s disease.
Scientists from Galway and Boston drew participants from the Framingham Heart Study, described as "the world’s longest running longitudinal cohort study", to collate the data.
The study in question started in 1948 with the recruitment of 5,200 adults from the town of Framingham in Massachusetts. Around 15% of them had Irish ancestry.
Children of the original cohort were recruited in 1971, to extend the scope of the study.
The Galway-led research is published in the Journal for Alzheimer’s Disease.
