Menopause is associated with brain changes similar to those seen in Alzheimer’s disease, according to a large British study.

Researchers speculate that loss of gray matter in areas associated with memory and emotion may explain, in part, why women are generally at higher risk of dementia than men.

The findings were obtained from approximately 125,000 women, 11,000 of whom had undergone MRI brain scans.

In a study published in a magazine psychiatrythe use of hormone replacement therapy (HRT) did not seem to prevent gray matter loss.

Senior author Professor Barbara Sahakian from the University of Cambridge said: ‘The areas of the brain where we found these differences are areas that are more susceptible to Alzheimer’s disease.

“Menopause may make these women even more vulnerable in the future. It may help explain why dementia cases are almost twice as common in women as in men, although not in all cases.”

Changes in the brain occurred in the following locations:

• A region that plays an important role in learning and memory – hippocampus
• A region essential for memory formation and spatial navigation – entorhinal cortex
• Part that helps with attention and emotional regulation – anterior cingulate cortex

White matter and gray matter are both important parts of the brain and spinal cord.

Gray matter consists of nerve cell bodies and their dendrites, short projections that communicate with nearby neurons.

White matter is made up of long axons of neurons that transmit impulses to more distant regions of the brain and spinal cord.

According to NHS guidelines, HRT can be considered for menopausal symptoms such as sleep disturbances and hot flashes.

Researchers say the effects of menopause and HRT use on the brain, memory and mood are not fully understood.

The study found that women taking HRT were more likely to suffer from poor mental health. However, some people’s mental states were already deteriorating before they were prescribed drugs.

Co-researcher Dr Christel Langley said it was important to recognize the challenges associated with menopause.

“We all need to be more sensitive not only to the physical health of menopausal women, but also to their mental health.

“There’s no shame in letting others know what you’re going through and asking for help.”

Michelle Dyson, from the Alzheimer’s Society, said women accounted for around two thirds of people living with Alzheimer’s disease in the UK.

“And while it is still not fully understood why they are more susceptible than men, it is thought that hormones may play a role,” she says.

“This large-scale study adds to the evidence of how menopause affects the brain, including physical changes such as decreased brain volume.

“However, without long-term follow-up to see whether participants later develop dementia, we cannot be sure whether brain changes associated with menopause increase the risk of dementia.”

She said regular exercise, smoking cessation and limiting alcohol intake can help reduce the risk of dementia.