Weight loss treatment may cut risk of dementia, stroke and early death, study finds

New research suggests that weight loss injections such as Wegovy and Mounjaro may offer protective benefits against dementia, stroke and premature death in people living with type 2 diabetes and obesity.

The study, published in JAMA Network Open, found that people taking GLP-1 receptor agonists – the class of drugs that includes semaglutide and tirzepatide – had a 37 per cent lower risk of developing dementia and a 19 per cent lower risk of stroke, compared with those taking other diabetes medications. They were also 30 per cent less likely to die during the seven-year follow-up period.

Researchers in Taiwan analysed data from 60,000 people worldwide with an average age of 58, all of whom were living with type 2 diabetes and obesity. About half had been prescribed semaglutide or tirzepatide – known by brand names such as Ozempic, Wegovy and Mounjaro – while the rest used other antidiabetic treatments.

GLP-1 agonists help manage blood sugar by increasing insulin production, reducing appetite, slowing digestion and limiting sugar output from the liver. While their benefits for weight loss and diabetes are well established, researchers say their wider impact on brain and cardiovascular health remains under investigation.

The study found the greatest benefits among people aged 60 or over, women and those with a body mass index (BMI) between 30 and 40. However, no significant differences were observed in the incidence of Parkinson’s disease or cerebral haemorrhage.

“These findings suggest that semaglutide and tirzepatide may offer neuroprotective and cerebrovascular benefits beyond glycaemic control,” the authors wrote. “They may potentially improve long-term cognitive and survival outcomes in adults living with type 2 diabetes and obesity.”

Commenting on the study, Professor Tara Spires-Jones, director of the Centre for Discovery Brain Sciences at the University of Edinburgh and group leader at the UK Dementia Research Institute, said: “This is a very interesting study adding to evidence that GLP-1 receptor agonists are associated with a lower risk of dementia in people living with type 2 diabetes and obesity.”

However, she cautioned that observational studies cannot confirm cause and effect. “It is highly likely that effectively treating type 2 diabetes and obesity would reduce dementia and stroke risk as they are known risk factors for these conditions,” she said. “Further work is needed, including randomised clinical trials.”

Dr Richard Oakley, associate director of research and innovation at Alzheimer’s Society, added: “This study supports existing evidence that these drugs may reduce dementia risk, particularly in people aged 60 and over living with type 2 diabetes and obesity.

“Although interesting, we can’t draw firm conclusions from this study alone. Only a small number of participants went on to develop dementia and the impact of these drugs on different types of dementia remains unclear.

“There are clinical trials under way looking at whether drugs like these can treat early-stage Alzheimer’s disease. This is a really exciting area being explored in the research fight against dementia.”