An older sibling of the popular diabetes and weight loss drug semaglutide may help slow the progression of Alzheimer’s disease. In clinical trial data released this week, UK scientists have found evidence that liraglutide can reduce brain shrinkage and cognitive decline in Alzheimer’s patients. Semaglutide is already being tested out in larger Phase III trials for the neurodegenerative condition.
Liraglutide and similar drugs mimic the hormone GLP-1, which helps regulate our blood sugar and appetite. It was approved in 2010 to treat type 2 diabetes; in 2014, it was approved to treat obesity. People with poorly controlled diabetes are known to be at higher risk for Alzheimer’s and other forms of dementia, while some studies in animals have suggested that liraglutide can prevent the damaging brain changes that occur in Alzheimer’s. So scientists at the Imperial College London decided to conduct a double-blinded, randomized, and placebo-controlled trial of liraglutide for Alzheimer’s.
The trial involved 204 patients diagnosed with early Alzheimer’s, half of whom were given liraglutide. The drug didn’t appear to significantly change people’s glucose metabolism in the brain, which was the primary measure of the study. But the researchers did find that people on liraglutide experienced an almost 50% slower decline in brain volume loss than people taking placebo over the next year. Those on the drug also experienced an 18% slower decline in measured cognitive function during that time. The team’s findings were presented this week at the Alzheimer’s Association International Conference.
This research is preliminary; it hasn’t yet gone through the peer-review process. And assuming the results are valid, it’s still not clear exactly how liraglutide might be improving people’s brains for the better. But the researchers do have several possible explanations.
“We think liraglutide is protecting the brain possibly by reducing inflammation, lowering insulin resistance and the toxic effects of Alzheimer’s biomarkers or improving how the brain’s nerve cells communicate,” said study researcher Paul Edison, a professor of neuroscience at Imperial’s Department of Brain Sciences, in a statement from the university.
Perhaps the most exciting part of this research is that more potent GLP-1 drugs have emerged since this study began, such as semaglutide. Semaglutide (sold under the names Ozempic and Wegovy) and the even newer tirzepatide (Mounjaro and Zepbound) have proven to be substantially more effective at treating diabetes and obesity than older GLP-1 medications like liraglutide. And a study published just last month has already found evidence that semaglutide can boost brain health in people with type 2 diabetes.
The makers of both liraglutide and semaglutide, Novo Nordisk, are currently conducting two large-scale, placebo-controlled trials to see whether semaglutide can improve the trajectory of people diagnosed with early Alzheimer’s disease. If these results, expected to arrive within the next few years, are positive, they should lead to semaglutide and other GLP-1 drugs becoming the latest tool in a growing arsenal of anti-Alzheimer’s medications.
