The regions of the brain responsible for memory, spatial navigation and emotional regulation were most affected
Experts from the University of Cambridge carried out a study on 124,780 women to examine the effects of menopause on the brain and to discover whether hormone replacement therapy (HRT) plays a role in preventing cognitive decline.
They found that menopause is linked to a loss of brain grey matter, which is vital for mental functions, memory, emotions and movement, and that menopause can bring on anxiety, depression and sleep problems.
The study found that post-menopausal women who were not on HRT had slower reaction times than those who had not reached menopause yet or who were on HRT. However, there were no significant differences among the three groups when it came to performance on memory tasks.
The study, published in the journal Psychological Medicine, looked at women who were pre-menopause, post-menopausal having never used HRT and post-menopausal having used HRT.
Women answered questions in areas such as sleep and whether they suffered depression and anxiety, and some took part in cognitive tests.
Women are more likely to suffer from insomnia post-menopause. Stock image. Photo: Getty
Around 11,000 women also underwent magnetic resonance imaging (MRI) scans so experts could look at their brain structure.
The average age of onset of menopause among the women was 49 and those on HRT were around that age when they started treatment.
Post-menopausal women were more likely to report insomnia, getting less sleep overall and feeling tired, the study found. Those on HRT reported feeling the most tired of all three groups, even though they slept the same amount as women not on HRT.
All post-menopausal women, whether on HRT or not, said they were more tired than women who had not gone through it.
Menopause also affected cognition.
Katharina Zuhlsdorff, from the University of Cambridge’s department of psychology, said: “As we age, our reaction times tend to get slower. It’s just a part of the natural ageing process and it happens to both women and men.
Menopause could make these women vulnerable further down the line
“You can imagine being asked a question at a quiz. While you might still arrive at the correct answer as your younger self, younger people would no doubt get there much faster.
“Menopause seems to accelerate this process, but HRT appears to put the brakes on, slowing the ageing process slightly.”
Researchers found significant reductions in volume of grey matter in those women who were post-menopausal. In particular, these differences occurred in the hippocampus (which has a major role in learning and memory), the entorhinal cortex (essential for forming memories and spatial navigation) and the anterior cingulate cortex (which helps with attention and regulating emotions).
Barbara Sahakian, the study’s senior author, said: “The brain regions where we saw these differences are ones that tend to be affected by Alzheimer’s disease.
“Menopause could make these women vulnerable further down the line.
“While not the whole story, it may help explain why we see almost twice as many cases of dementia in women than in men.”