Primarily prescribed for type 2 diabetes and weight loss, medications like Ozempic and Zepbound are also showing promise in treating a range of other conditions, from sleep apnea to chronic kidney disease.
Now, a new study published in JAMA Network Open suggests that for people with obesity and type 2 diabetes, these drugs—known as GLP-1 receptor agonists—may also reduce the risk of death and lower the chances of developing two brain-related conditions: dementia and ischemic stroke.
Type 2 diabetes and obesity are “major drivers” of these conditions, said the study’s first author, Huan-Tang Lin, MD, PhD, an attending physician and associate professor of anesthesiology at Chang Gung College of Medicine in Taiwan.
“This extends [GLP-1s’] therapeutic scope from glycemic control, weight loss, and cardiovascular control to direct neuro- and cerebrovascular protection,” Lin told Health.
Researchers have previously found that GLP-1s may help protect against dementia and stroke. But according to the authors of the study, “large-scale clinical studies evaluating their association with neurodegenerative and cerebrovascular outcomes remain limited, particularly in high-risk patients with both type 2 diabetes and obesity.”
To help fill the gap, researchers examined seven years’ worth of health data from more than 60,000 participants, all of whom had type 2 diabetes and obesity.
Some participants were taking diabetes drugs like biguanides (such as metformin), sulfonylureas, and dipeptidyl peptidase 4 inhibitors. Others were prescribed the GLP-1s semaglutide or tirzepatide. (Semaglutide is the active ingredient in Ozempic, Wegovy, and Rybelsus; tirzepatide is used in Mounjaro and Zepbound.)
After analyzing associations between the medications and various brain-related conditions, the scientists discovered that participants taking a GLP-1 had a:
- 37% lower risk of dementia
- 19% lower risk of ischemic stroke (the most common type, caused by a blocked blood vessel supplying the brain)
- 30% lower risk of death from any cause
The protective effect against dementia was especially pronounced in women over 60 and those with a BMI between 30 and 40. “Patients in this window have an especially powerful opportunity to bolster brain health,” said Meghan Garcia-Webb, MD, a triple-board-certified physician in internal medicine, lifestyle medicine, and obesity medicine in Massachusetts.
Meanwhile, GLP-1s did not appear to reduce the risk of Parkinson’s disease or hemorrhagic stroke, which can occur when a weakened blood vessel ruptures and bleeds in the brain.
The study “adds to the growing body of research suggesting GLP-1 receptor agonists are powerful tools—not just for weight loss and diabetes, but potentially for neurological health and cognition as well,” Garcia-Webb told Health.
Still, the research isn’t without limitations. Like any observational study, it shows only an association—not causation. Lifestyle habits, rather than the GLP-1 medications, could have influenced the results, Lin noted.
In addition, researchers didn’t collect biomarkers, genetic data, or brain imaging, all of which would have offered more insight into what’s actually happening in the body.
Lin emphasized that the findings “should be interpreted with caution” and confirmed in rigorously designed randomized controlled trials before informing clinical recommendations.
While the new study doesn’t definitively prove that GLP-1s reduce the risk of dementia and stroke, some research reveals how they might help.
Scientists have found that GLP-1s reduce biomarkers linked to Alzheimer’s disease and dementia, such as amyloid-β peptide accumulation and neuroinflammation.
These medications may also improve blood vessel function and help stabilize plaque buildup in the arteries, which could lower the chance of an ischemic stroke. Because tirzepatide targets two hormones instead of one, it may enhance these protective effects.
Weight loss itself may also play a role.
“When people lose a significant amount of weight, as many do on semaglutide and tirzepatide, it not only reduces inflammation and improves blood sugar, but it also enables them to have improved mobility and less mechanical joint stress,” Garcia-Webb said. “Patients who can move and exercise more comfortably and more often can further improve their cardiovascular, metabolic, and mental health.”
