A major study using brain MRIs from over 31,000 adults suggests that type 2 diabetes and prediabetes may lead to accelerated brain aging.

Those with diabetes, especially when uncontrolled, showed brains that were significantly older than their chronological age. However, lifestyle choices like exercise and avoiding smoking and excessive drinking may mitigate these effects.

Diabetes, Prediabetes, and Brain Aging

Type 2 diabetes is a known risk factor for dementia, but it is unclear how diabetes and its early stages, known as prediabetes, affect brain aging in people without dementia. Now, a comprehensive brain imaging study shows that both diabetes and prediabetes can be linked to accelerated brain aging.

The study included more than 31,000 people between 40 and 70 years of age from the UK Biobank who had undergone a brain MRI scan (magnetic resonance imaging). The researchers used a machine learning approach to estimate brain age in relation to the person’s chronological age.

Impact of Diabetes Control on Brain Age

Prediabetes and diabetes were associated with brains that were 0.5 and 2.3 years older than chronological age, respectively. In people with poorly controlled diabetes, the brain appeared more than four years older than chronological age. The researchers also noted that the gap between brain age and chronological age increased slightly over time in people with diabetes. These associations were attenuated among people with high physical activity who abstained from smoking and heavy alcohol consumption.

Study Insights and Future Research

“Having an older-appearing brain for one’s chronological age can indicate deviation from the normal aging process and may constitute an early warning sign for dementia,” says the study’s lead author Abigail Dove, a PhD student at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet. “On the positive side, it seems that people with diabetes may be able to influence their brain health through healthy living.”

Repeated MRI data were available for a small proportion of the study participants. Follow-up MRI scans are ongoing and researchers are now continuing to study the association between diabetes and brain ageing over time.

Implications for Prevention and Management

“There’s a high and growing prevalence of type 2 diabetes in the population,” says Abigail Dove. “We hope that our research will help prevent cognitive impairment and dementia in people with diabetes and prediabetes.”

Reference: “Diabetes, prediabetes, and brain aging: the role of healthy lifestyle” by Abigail Dove, Jiao Wang, Huijie Huang, Michelle M. Dunk, Sakura Sakakibara, Marc Guitart-Masip, Goran Papenberg and Weili Xu, 28 August 2024, Diabetes Care.
DOI: 10.2337/dc24-0860

The study was mainly funded by the Swedish Alzheimer’s Foundation, the Dementia Research Fund, the Swedish Research Council, and Forte (the Swedish Research Council for Health, Working Life and Welfare). There are no reported conflicts of interest.