Researchers who analysed brain scans from hundreds of people aged 70 have revealed how lifestyle changes could prevent premature brain ageing and boost resilience against conditions like dementia.

MRI scans from 739 people suggested certain health conditions can accelerate biological ageing. Those with a history of diabetes, stroke, cerebral small vessel disease or inflammation typically had older-looking brains.

Meanwhile, the brains of those who lived healthier lifestyles involving regular exercise tended to appear younger.

Study leader Anna Marseglia, researcher in neurology at Sweden’s Karolinska Institutet, said: “Despite the recent introduction of new Alzheimer’s drugs, they will not work for everyone with dementia, so we want to study what can boost the brain’s resilience against pathological ageing processes.

“A take-home from the study is that factors that adversely affect the blood vessels can also be related to older-looking brains, which shows how important it is to keep your blood vessels healthy, to protect your brain, by making sure, for instance, that your blood glucose level is kept stable.”

Such health conditions may not always be caused by lifestyle factors, but a person’s risk of developing them can often be reduced through simple changes.

People who are overweight or obese and have inactive lifestyles are significantly more likely to develop type 2 diabetes. And factors such as high blood pressure, poor diet and smoking can raise risk of suffering a stroke.

The research involved taking MRI scans of people’s brains and using an artificial intelligence algorithm to estimate their age based on the images.

This allowed the team to calculate the “brain age gap” by subtracting a patient’s estimated biological brain age from their chronological age.

Principal investigator Eric Westman, professor of neurogeriatrics at the Karolinska Institute, said: “The algorithm is both accurate and robust, yet easy to use.

“It’s a research tool that still needs further evaluation, but our aim is for it also to be of clinical use in the future, such as in dementia investigations.”

The team plans to launch a study next year which will investigate how factors such as social connectedness, sleep and stress influence brain resilience.

The findings were published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.