Two undergraduate medicine students at University of Galway have led a major study examining how cardioprotective glucose-lowering therapies - medications that lower blood sugar and reduce the risk of heart disease in people with diabetes - affect the risk of developing dementia.

The research has been published in JAMA Neurology.

The new study involved a systematic review and meta-analysis of 26 clinical trials involving more than 160,000 participants.

The researchers found that while most glucose-lowering therapies were not significantly associated with a reduction in dementia risk, one class of drugs – known as GLP-1 receptor agonists (GLP-1Ras) was linked to a significant reduction.

The study was conducted by medical students Allie Seminer and Alfredi Mulihano, alongside researchers from University of Galway, the HRB Clinical Research Facility Galway and University Hospital Galway.

Key Findings:

• The research analysed data from 26 randomised controlled trials with a total of 164,531 participants.
• While glucose-lowering therapies as a whole did not significantly reduce dementia risk, GLP-1 receptor agonists (GLP-1Ras) were linked to a 45% lower risk of dementia.
• The findings provide crucial insights into the potential for diabetes medications to influence long-term brain health.

Dr Catriona Reddin, senior author, researcher at the University of Galway and Registrar in Geriatric Medicine at HSE West North West, said: "This research represents a significant contribution to our understanding of how some diabetes medications may impact brain health. Diabetes is a known risk factor for dementia, but whether glucose-lowering therapies can help prevent cognitive decline has remained unclear. Our findings suggest that GLP-1 receptor agonists, in particular, may have a protective effect on brain health.”

Professor Martin O'Donnell, Dean of the College of Medicine, Nursing and Health Sciences at University of Galway and Consultant Stroke Physician with HSE West North-West said: “Given the increasing prevalence of both diabetes and dementia, findings from this study have important public health implications for prevention of dementia.

“What makes this study particularly exciting for the College of Medicine, Nursing and Health Sciences at University of Galway, is that it was led by two of our undergraduate medicine students. We place a strong emphasis on research as a core component of our undergraduate medicine programme, ensuring that students have opportunities to engage in high-impact studies that shape global healthcare.”

Allie Seminer, a third year student from New York and co-lead author, said: "Being involved in a study of this scale as an undergraduate has been an incredible experience. What stood out for me was the sense of responsibility - knowing that our work could help shape understanding of a global health issue. It was incredibly motivating to be part of a team working at this level, and it has shown me how research is an essential part of becoming a well-rounded doctor. It highlights how research is not just an add-on to our degree but an essential part of how we learn to advance medical knowledge."

Alfredi Mulihano, a third year student from Dundalk and co-lead author, said:  "Being part of this study has completely changed how I see my role as a future doctor. It brought together clinical insight, data analysis, and critical thinking in a way that lectures alone cannot. The experience opened my eyes to the impact we can have beyond the bedside - contributing to knowledge that could change how diseases like dementia are prevented.”

The full study in JAMA Neurology is available here.

Ends