Obesity and diabetes medications could offer brain-protective benefits, new studies suggest

Medications used to treat obesity and type 2 diabetes — particularly semaglutides such as Ozempic and Wegovy — may reduce the risk of dementia, according to new research.

The findings, drawn from two major studies, suggest that these drugs may offer a protective effect on the brain, although experts stress that more research is needed to fully understand how they might influence cognitive health.

One US study analysed health records from nearly 400,000 adults aged over 50 with type 2 diabetes, tracked between 2014 and 2023. None of the participants had been diagnosed with Alzheimer’s disease or related dementias at the start of the study. Researchers looked at patients taking GLP-1 receptor agonists (GLP-1RAs), such as semaglutide, or SGLT-2 inhibitors (SGLT-2i), and compared them with those on other glucose-lowering treatments.

The results showed a statistically significant reduction in dementia risk for those taking either GLP-1RAs or SGLT-2 inhibitors, with no major difference between the two groups. However, semaglutide in particular appeared to stand out. “Semaglutide seems to be promising in reducing the risk of Alzheimer’s and related dementias,” researchers noted, highlighting previous findings around the drug’s potential neuroprotective properties.

Wegovy, a semaglutide-based drug, was approved for NHS weight loss treatment in 2023, while Ozempic and Rybelsus are already prescribed for type 2 diabetes.

Dr Leah Mursaleen, Head of Clinical Research at Alzheimer’s Research UK, welcomed the findings, saying: “This study supports growing evidence that GLP-1RA and SGLT-2 inhibitor medicines may reduce dementia risk. We still don’t know why these drugs might have this effect, and more research is needed to explore how they impact the brain.”

However, she also warned that other factors — such as overall health, education and income — could be influencing the results. “These are interesting findings, but we must consider the bigger picture,” she said.

A second study led by researchers in Ireland further backed the case for GLP-1RAs, analysing 26 clinical trials involving nearly 165,000 patients. While most diabetes drugs, including metformin and pioglitazone, were not associated with reduced dementia risk, GLP-1 receptor agonists showed a statistically significant benefit.

Professor Tara Spires-Jones, Director of the Centre for Discovery Brain Sciences at the University of Edinburgh and President of the British Neuroscience Association, described the data as “encouraging”. However, she noted inconsistencies in findings related to SGLT-2 inhibitors and emphasised the need for longer-term studies.

“It’s important to remember these medications have side effects and aren’t guaranteed to prevent dementia,” she said. “The follow-up time in the studies was relatively short, and we still have more to learn about how risk factors like diabetes and obesity contribute to dementia.”

Professor Masud Husain, Professor of Neurology and Cognitive Neuroscience at the University of Oxford, added: “For me, these new retrospective analyses suggest that GLP-1 receptor agonists —particularly semaglutide — might reduce the risk of developing dementia in people with type 2 diabetes.”

Both studies have been published in JAMA Neurology.