New trial finds liraglutide reduces brain shrinkage by nearly 50% in Alzheimer’s patients and slows cognitive decline by up to 18% within a year
Researchers at Imperial College London found that liraglutide, a drug used for diabetes and weight loss, slowed brain shrinkage and cognitive decline in people with mild Alzheimer’s during a double-blind trial. After one year, patients taking liraglutide had nearly 50% less brain volume loss and a slower decline in memory compared to those on a placebo. This marks a significant step forward.
The research is published in Nature Medicine.
How the trial worked and what researchers found
Liraglutide is a type of drug called a GLP-1 agonist, similar to semaglutide, which is better known as Ozempic. While these drugs are approved for weight loss and obesity, researchers are now finding they may have other uses too.
The study included 204 people with mild Alzheimer’s disease. Half received a daily injection of up to 1.8 mg of liraglutide, while the other half got a placebo injection.
Before the study began, participants had brain MRIs to assess structure and volume, PET scans to assess glucose metabolism, and detailed memory tests. These tests were done again at the end of the study.
Participants who took liraglutide lost almost 50% less brain volume in several areas, as shown by MRI scans. Researchers also tested memory and thinking skills before treatment, and again at 24 and 52 weeks. Although the study was not primarily designed to measure cognitive changes, they found that people on liraglutide had a 18% slower decline in cognitive function over one year compared to those on placebo.
Brain scans showed shrinkage in the frontal, temporal, and parietal lobes, as well as in the total grey matter. These areas are important for memory, learning, language, and decision-making.
These findings suggest that liraglutide may help protect the brains of people with mild Alzheimer’s and slow cognitive decline by 18% over a year.
How liraglutide may protect the brain
Researchers are not yet sure how liraglutide affects the brain. They think its protective effect may stem from influencing several processes, such as reducing inflammation, modulating tau protein buildup, lowering insulin resistance, and modulating amyloid. These actions may help slow brain volume loss.
Professor Paul Edison, Professor of Neuroscience at Imperial’s Department of Brain Sciences, said: “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.”
Professor Edison explained that because liraglutide and other GLP-1 analogues are already licensed for managing obesity and diabetes, their path to treatment for Alzheimer’s could be swift.
He added, “If scientists are able to further demonstrate that this is working in patients with Alzheimer’s disease in phase 3 trials, and the FDA approves it for Alzheimer’s, this drug could then be immediately available.”
Two separate phase 3 trials are already in progress, and results are expected by the end of 2025.
