Blockbuster weight loss drugs could slash the risk of developing memory-robbing dementia, a major study suggests.
Researchers in Ireland analyzed clinical trials of nearly 165,000 taking drugs to lower their glucose (blood sugar) and treat diabetes.
The team found most glucose-lowering treatments had no significant impact on dementia risk.
However, people taking GLP-1 agonists like Ozempic and Wegovy were 45 percent less likely to develop dementia at some point in their lives than people on other drugs.
While it’s unclear exactly how the active ingredients in these drugs – most often semaglutide and tirzepatide – reduce the likelihood of dementia, the researchers believe they may lower inflammation in the brain.
Neuroinflammation is thought to damage neurons and disrupt communications to part of the brain responsible for memory, triggering dementia symptoms.
GLP-1 agonists may also reduce toxic amyloid and tau proteins, hallmarks of dementia.
The team suspects GLP-1 agonists like Ozempic may help prevent both diabetes and dementia, both of which are on the rise in the US.

Semaglutide and tirzepatide — the powerful ingredients behind Wegovy, Ozempic and Mounjaro — have long been hailed a monumental breakthrough in the war on obesity and type 2 diabetes

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Dr Catriona Reddin, senior study author and researcher at the University of Galway, 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.’
The study comes after a similar experiment from the University of Florida, which tracked 400,000 Americans on glucose-lowering drugs and found dementia risk was 33 percent lower for GLP-1 users compared to other interventions.
Around 8million adults in the US have some form of dementia, and 500,000 are diagnosed every year.
Meanwhile, one in eight US adults has reported taking Ozempic or similar medications at least once for diabetes or weight loss.
In the new study, published in JAMA Neurology, researchers identified 26 studies that explored the relationship between GLP-1 agonist use and dementia.
These included a total of 164,531 participants, most of whom (65 percent) were men. The average age was 64 with a follow-up time of 31 months.

Wendy Williams, pictured here, is one of the most famous faces of dementia. She was diagnosed with frontotemporal dementia in 2023 at age 59

Bruce Willis (pictured here) was also diagnosed with frontotemporal dementia in 2023
Studies included in the analysis were published between 2015 and 2024. Of the 26 in the review, 10 looked at the impact of GLP-1 agonists.
The team suspected GLP-1 agonists may lower inflammation, which is a major driver of dementia. It’s thought to activate the immune cells microglia and astrocytes in the brain, which damage neurons and disrupt the blood-brain barrier, the brain’s protective layer.
GLP-1 agonists have also been shown to lower blood pressure and protect blood vessels, reducing the risk of vascular dementia.
A study published in April also found GLP-1s may stimulate neural growth in the hippocampus, an area of the brain responsible for learning and memory formation. However, this research is early.
Professor Martin O’Donnell, Dean of the College of Medicine, Nursing and Health Sciences at University of Galway: ‘Given the increasing prevalence of both diabetes and dementia, findings from this study have important public health implications for prevention of dementia.’
Recent reports from the Alzheimer’s Association report rates of Alzheimer’s disease – the most common form of dementia – have risen 25 years in a row in the US.
Diabetes, meanwhile, affects 12 percent of Americans – 38million. Reports published in 2022 suggest rates in the Americas have tripled in the last 30 years.
There were several limitations to the new study, mainly including a lack of data on subtypes of dementia like vascular and Lewy body dementia.
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