Oct 21, 2025 12:00:00

Research shows that men are more susceptible to age-related brain atrophy than women

The question of whether there are differences between the male and female brains has been around for a long time. While recent advances include

the development of an AI model that can identify gender from brain scans with over 90% accuracy, and research showing that women's brains are biologically younger than men's, a new study from a research team at the University of Oslo in Norway has shown that men's brains shrink more rapidly with age than women's.

Sex differences in healthy brain aging are unlikely to explain higher Alzheimer's disease prevalence in women | PNAS
https://www.pnas.org/doi/10.1073/pnas.2510486122

Male Brains Shrink Faster Than Female Brains, Study Finds : ScienceAlert
https://www.sciencealert.com/male-brains-shrink-faster-than-female-brains-study-finds

It is natural for the human brain to shrink with age, and it is known that the brain volume of people who die from Alzheimer's disease is significantly reduced. It is also known that women are twice as likely as men to be diagnosed with Alzheimer's disease, but the influence of gender on brain shrinkage with age is not well understood.

'If women's brains are declining more dramatically, this may explain why women are more susceptible to Alzheimer's,' said lead author Ann Ravndal, a neuroscientist at the University of Oslo.

So Ravndal and his team looked at structural changes in the brain over time using 12,638 brain scans collected over many years from 4,726 participants aged 17 to 95. The participants had at least two MRI brain scans, with the average interval between scans being about three years.

Taking into account differences in brain size between men and women, the analysis revealed that the decline in brain area and volume that occurs with age is greater in men than in women. However, women reported that fewer areas of the brain atrophy with age, and the thickness of

the cerebral cortex also showed less change with age.

The figure below shows the degree of decrease in the area of the cerebral cortex with age. Areas with greater decrease in the female brain are shown in yellow, while areas with greater decrease in the male brain are shown in green. It can be seen that the extent of area decrease with age is greater in men.

The figure below shows the degree of loss of thickness in the cerebral cortex with age. Areas with greater loss in the female brain are shown in yellow, while areas with greater loss in the male brain are shown in green. As you can see, men experience greater loss of thickness.

What surprised the research team was that there were no sex differences in the volumetric changes of the hippocampus , which is closely related to memory, learning, and dementia.

Scientists are just beginning to understand the relationship between brain shrinkage and disease, and in some cases, it has been reported that brain shrinkage may be beneficial for cognitive function .

The results of this study suggest that there are sex differences in biological changes associated with aging, but further research is needed to correctly interpret the results.