Researchers at Karolinska Institutet have used an AI tool to analyze brain images from 70-year-olds, revealing that poor vascular health can make the brain appear older. Factors like inflammation and high blood sugar levels are linked to older-looking brains, while healthy lifestyles are associated with younger-looking brains. These findings were published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

Every year, over 20,000 people in Sweden are diagnosed with dementia, with Alzheimer’s disease making up about two-thirds of these cases. Various risk and health factors influence the speed of brain ageing.

“New Alzheimer’s drugs won’t work for everyone with dementia, so we’re studying ways to boost the brain’s resilience against ageing,” says Anna Marseglia, the study’s lead author and researcher at Karolinska Institutet.

AI-Derived Brain Age

The study involved 739 cognitively healthy 70-year-olds from Gothenburg’s H70 cohort in Sweden. Using MRI scans and an AI-based algorithm, the researchers estimated the biological age of their brains.

“The algorithm is accurate, robust, and easy to use,” says Eric Westman, principal investigator and professor of Neurogeriatrics. “It needs further evaluation but may eventually be useful in clinical settings, such as dementia investigations.”

Factors Influencing Brain Age

The study collected blood samples alongside brain scans to measure lipids, glucose, and inflammation. Participants also completed cognitive tests and provided data on lifestyle factors like exercise and medical conditions.

The AI tool estimated the average brain age to be 71 years. By comparing participants’ biological brain age to their actual age, researchers found that diabetes, stroke, small vessel disease in the brain, and inflammation were linked to older-looking brains. In contrast, a healthy lifestyle with regular exercise was linked to younger-looking brains.

“Keeping your blood vessels healthy is important for protecting your brain. For example, maintaining stable blood glucose levels can help prevent your brain from ageing prematurely,” says Anna Marseglia.

Future Research on Sex Differences

The study also found differences between men and women in terms of factors linked to brain age. Researchers plan to investigate how social health, including social engagement, connectedness, and support, along with sleep and stress, influence brain resilience, particularly focusing on women’s health factors.

“Next year, we’ll start a study to understand the impact of social health on brain resilience, especially in middle and older age,” adds Marseglia.