Weight Loss and Diabetes Drug Could Slow Alzheimer’s Progression, Preliminary Study Suggests

A drug used to treat weight loss and diabetes may slow cognitive decline in people with mild Alzheimer’s disease, according to research from a mid-stage trial presented in late July at the Alzheimer’s Association International Conference. The findings have not yet been published in a peer-reviewed journal.

“This looks promising,” Alberto Espay, a neurologist at the University of Cincinnati, says to NBC News’ Berkeley Lovelace Jr. “If this is replicated in a phase 3 trial, it could become the first truly disease-modifying treatment in Alzheimer’s disease.”

Experts said larger studies were needed to confirm the results. But the findings add to a growing body of research looking into whether diabetes and weight loss drugs can be used to treat Alzheimer’s.

“It leads us to really think about the promise of these types of new medications for Alzheimer’s disease or other types of dementia,” Rebecca Edelmayer, senior director of scientific engagement for the Alzheimer’s Association, says to USA Today’s Ken Alltucker.

Drugs called glucagon-like peptide-1 (GLP-1) agonists, which include Ozempic and Mounjaro, are used to help people lose weight, manage their diabetes and lower their risk of heart disease, stroke and kidney disease, according to a statement from the conference. Research in animals has suggested these medications may also reduce levels of amyloid protein in the brain, which is linked to Alzheimer’s disease.

Researchers tested one of these GLP-1 agonists called liraglutide, sold as the weight loss drug Saxenda and the diabetes drug Victoza. Liraglutide has not been approved to treat Alzheimer’s.

For the new study, the team recruited 204 people with mild Alzheimer’s disease from 24 different clinics in the United Kingdom. Half received a daily injection of liraglutide for a year, while the other half received a placebo. The patients took memory tests and received MRIs to measure their brain structure and volume, as well as PET scans to measure glucose metabolism, which is tied to Alzheimer’s.

“This is the first study that actually looked at a relatively large number of patients for whether there is any neuroprotective effect in Alzheimer’s disease,” Paul Edison, who led the research and is a neuroscientist at the Imperial College London, tells CNN’s Meg Tirrell.

Many brain regions shrink in people with Alzheimer’s. But participants who received liraglutide had 50 percent less shrinkage in several parts of the brain related to memory, learning, language and decision-making, compared to the control group. Patients who received the drug also had 18 percent less cognitive decline, as measured by different tests of memory, comprehension, language and spatial orientation.

However, the treatment did not appear to significantly affect people’s glucose metabolism in the brain.

Espay tells NBC News that it makes sense that GLP-1s seem to help protect the brain because Alzheimer’s is a “syndrome of many diseases caused by different biological, toxic or infectious exposures.”

In the treatment group, 79 people completed a year of treatment, as did 87 people in the placebo group. The most common side effect was gastrointestinal issues such as nausea.

“Having a drug which has got a very good safety profile and could be used widely—it will change the field significantly,” Edison tells CNBC’s Annika Kim Constantino.

Novo Nordisk, the company that sells the drug, partially funded the new research, per CNBC.

“The study was carried out in a small group of people,” Sheona Scales, director of research at Alzheimer’s Research UK, says to the Guardian’s Andrew Gregory. “Larger trials are now happening to see whether drugs like liraglutide are effective at slowing down the progression of Alzheimer’s disease.”

A three-year clinical trial testing the GLP-1 agonist semaglutide—sold as the diabetes drug Ozempic and the weight-loss drug Wegovy—in 1,800 people with early Alzheimer’s disease is ongoing, according to the statement.

Will Sullivan | | READ MORE

Will Sullivan is a science writer based in Washington, D.C. His work has appeared in Inside Science and NOVA Next.