High blood glucose levels accelerate brain aging

The researchers used data from the UK Biobank, a large database with medical, genetic, and imaging information on tens of thousands of people. First, they analyzed the MRI scans and identified more than a thousand signs of brain structure, such as the size of individual areas, tissue characteristics, and structural changes. On this basis, using machine learning, models were trained to predict the age of the human brain. The LASSO regression model performed the best job, with an average forecast error of only 3.26 years.

Then, the brain age gap (BAG) was calculated for 37,458 participants. BAG reflects the difference between a person’s actual age and the age of their brain based on MRI data, with a positive value indicating that the brain appears older than the person’s calendar age.

In the next step, the researchers compared BAG with metabolomics data, which involves analyzing molecules in the blood plasma of the same individuals. This allowed them to identify nine metabolites that were significantly associated with BAG. Among them, the glucose indicator turned out to be the strongest predictor: the higher the plasma glucose level, the greater the gap and the older the brain structures appeared in the images. Genetic analyses and the Mendelian randomization method further confirmed the potential causal role of glucose in accelerating brain aging.

Elevated glucose levels were associated not only with signs of aging on MRI scans but also with clinical risks. People with higher glucose concentrations were more likely to have seven conditions affecting brain function: dementia of any cause, Alzheimer’s disease, vascular dementia, Parkinson’s disease, stroke, depression, and anxiety disorders. They also had worse cognitive function, motor activity, and mental well-being.

Additionally, high glucose levels were correlated with reduced tissue volume in 80 regions of the brain, including the cortex, subcortical structures, and cerebellum. This suggests a widespread impact of carbohydrate metabolism disorders on neural tissue structure.

The study demonstrates that glucose metabolism is a potentially correctable factor affecting brain health. If the connection is indeed causal, controlling blood sugar levels could be one of the tools to slow down age-related changes and reduce the risk of neurological diseases.

The authors emphasize that their work provides a basis for early intervention strategies, tracking metabolic indicators, it is possible to identify people with an increased risk of accelerated brain aging in time and offer them measures to preserve cognitive health. Further research will help to better determine how exactly the correction of glucose levels affects long-term outcomes.