Healthcare (Commonwealth Union) – Brain aging is a multifaceted phenomenon characterized by structural, functional, and molecular changes that accumulate over time. These alterations can manifest as subtle shifts in memory, processing speed, and cognitive flexibility. While the rate and extent of brain aging vary among individuals, certain common patterns have emerged from decades of research.
Researchers at Karolinska Institutet used AI technology to analyze brain scans from individuals in their 70s and estimate the biological age of their brains. They discovered that harmful factors affecting vascular health, like inflammation and high blood sugar, are linked to an older-appearing brain, while healthier lifestyles are connected to a younger-looking brain. The findings are published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
Each year, over 20,000 people in Sweden are diagnosed with some form of dementia, with Alzheimer’s disease representing about two-thirds of these cases. However, the rate at which the brain ages depend on a range of risk and health factors.
The study’s lead author, Anna Marseglia, a researcher at the Department of Neurobiology, Care Sciences, and Society at Karolinska Institutet indicated that while new Alzheimer’s medications have been introduced recently, they won’t be effective for everyone with dementia. Therefore, they aim to explore ways to enhance the brain’s resilience against pathological aging.
The investigation encompassed 739 mentally agile septuagenarians, comprising 389 females, enlisted from Gothenburg’s H70 assembly.
Cerebral age deduced by AI The investigators captured MRI visuals of their brains and subsequently approximated the chronological state of these cerebral depictions utilizing their proprietary AI-driven computation.
“The algorithm is both accurate and robust, yet easy to use,” explained principal investigator Eric Westman, professor of Neurogeriatrics at the same department. “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 brain imaging was supplemented with blood samples to measure lipids, glucose, and markers of inflammation. Participants also completed cognitive tests, and data on lifestyle factors, such as exercise habits and medical conditions, were collected.
The AI tool estimated the average brain age of participants to be 71 years. To assess discrepancies, the researchers calculated the “brain age gap” by subtracting the estimated biological brain age from the participants’ chronological age.
Their analysis revealed that conditions such as diabetes, stroke, cerebral small vessel disease, and inflammation were associated with brains that appeared older. In contrast, a healthy lifestyle, particularly regular exercise, was linked to brains with a younger appearance.
“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,” said Anna Marseglia.
Researchers indicated that the brains of men and women appear to differ in factors associated with younger- or older-looking brains, suggesting distinct ways they may build resilience. Researchers plan to explore this further by examining both biological influences, such as hormones, and sociocultural factors.
Anna Marseglia pointer out that this year they will begin a study to investigate how social health—encompassing social engagement, connectedness, and support—in middle and older age, alongside sleep and stress, affects brain resilience, with a particular emphasis on women’s health factors.
The study received primary funding from several organizations, including the Centre for Innovative Medicine, Forte, the Swedish Research Council, the Swedish Brain Foundation, the Swedish Alzheimer’s Foundation, the Swedish Dementia Foundations, the David and Astrid Hagelén Foundation, StratNeuro, the Foundation for Geriatric Diseases at Karolinska Institutet, the Loo and Hans Osterman Foundation for Medical Research, the Gamla Tjänarinnor Foundation, and the Collaboratory on Research Definitions for Reserve and Resilience in Cognitive Aging and Dementia.
