Researchers at Sweden's Karolinska Institutet used artificial intelligence (AI) to evaluate brain images of 70-year-olds, revealing important information about the biological age of the brain and its relationship to lifestyle and vascular health. 

A recent study in Alzheimer's & Dementia: The Journal of the Alzheimer's Association discovered that vascular health variables such as high glucose levels, inflammation, and illnesses such as diabetes and stroke all contribute to the appearance of an aged brain. Conversely, a healthy lifestyle, which includes regular exercise, correlates with brains that appear physiologically younger than their chronological age.

The findings are critical for treating dementia, which affects over 20,000 people in Sweden every year. Alzheimer's disease accounts for around two-thirds of these cases. 

"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," says Anna Marseglia, the study's lead author and researcher at Karolinska Institutet's Department of Neurobiology, Care Sciences, and Society. 

The study looked at data from 739 cognitively healthy persons, including 389 women from the Gothenburg H70 cohort. The researchers used MRI images and an AI-based approach to calculate the ages of people's brains. The computer calculated each brain's "biological age" and compared it to its chronological age to determine the "brain age gap." 

"The algorithm is both accurate and robust, yet easy to use," explains Eric Westman, a neurogeriatrics professor at Karolinska Institutet. "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." 

Blood samples for glucose, lipids, and inflammation, as well as cognitive tests and lifestyle information, corroborated the brain imaging findings. 

The AI concluded that the subjects' average brain age was 71 years, which was nearly identical to their chronological age. Diabetes, stroke, and cerebral small artery disease have all been linked to older-looking brains; yet, regular exercise and stable blood glucose levels are related to younger-looking brains. 

She says, "A take-home from the study is that factors that adversely affect the blood vessels can also relate to older-looking brains." This underscores the criticality of maintaining healthy blood vessels to safeguard your brain, such as maintaining a stable blood glucose level.

The study also found potential differences in how men and women acquire brain resilience. Researchers want to look into biological factors such as hormones and societal influences on brain health.