Known for its benefits in treating diabetes and weight loss, Ozempic is showing surprising properties: it may also fight Alzheimer’s disease. It can reduce brain shrinkage in Alzheimer’s patients by nearly 50%. The drug, called liraglutide, belongs to the class of glucagon-like peptide-1 (GLP-1) receptor agonists, which also includes semaglutide – known as Wegovy or Ozempic – used to treat obesity and type 2 diabetes.
Researchers are now finding potential applications for these drugs beyond their original indications. In a study led by Professor Paul Edison at Imperial College London involving 200 Alzheimer’s patients, the brains of patients who took liraglutide showed significantly reduced brain shrinkage and slowed cognitive decline compared with those who received a placebo. Brain shrinkage was measured by brain imaging of the frontal, temporal, parietal and total gray matter lobes, the brain regions critical for memory, learning, language and decision-making, which are often affected by Alzheimer’s disease.
The results of this research, presented at the Alzheimer’s Association International Conference in the United States and awaiting peer review, suggest that liraglutide could protect the brains of people with mild Alzheimer’s and slow cognitive decline by up to 18% after one year of treatment. The researchers point out that “Although the precise mechanisms of action of liraglutide on the brain are not yet fully understood, they believe that its protective effect could be related to its ability to modulate several brain processes, such as inflammation, tau protein aggregation, insulin resistance and the presence of amyloids, thus helping to slow the decrease in brain volume.“This could be similar to the way statins protect the heart by lowering cholesterol levels.
Quoted by the same source, Professor Paul Edison, head of the Department of Brain Sciences at Imperial College, commented: “We believe that liraglutide protects the brain, possibly by reducing inflammation, decreasing insulin resistance and the toxic effects of Alzheimer’s disease biomarkers, or by improving communication between nerve cells in the brain.”.
Reduction of brain retraction
Brain volume loss is a common indicator of Alzheimer’s disease. As the disease progresses, the brain sustains damage that gradually affects other areas and lobes, leading to progressive shrinkage. The randomized, double-blind, placebo-controlled clinical trial included 204 patients with mild Alzheimer’s disease from 24 clinics across the UK. Half of the participants received a daily injection of up to 1.8 mg of liraglutide, while the other half received a placebo injection.
Before the study began, all patients underwent magnetic resonance imaging (MRI) scans to assess brain structure and volume, as well as PET scans for glucose metabolism and detailed memory testing. These scans were repeated at the end of the study. Although the primary endpoint of the study, focusing on changes in cerebral glucose metabolism, was not met, secondary endpoints regarding clinical and cognitive measure scores, as well as the exploratory endpoint of brain volume, showed statistically significant improvement.
Participants who received liraglutide had nearly 50% less brain volume loss in several brain regions, as measured by MRI. The researchers also conducted cognitive tests before treatment, at 24 weeks, and at 52 weeks. Although the study was not originally designed to assess cognitive changes, the results showed that patients treated with liraglutide had 18% slower cognitive decline over the course of a year compared with those who received placebo.
Professor Edison said that since liraglutide and other GLP-1 analogues are already approved for obesity and diabetes, their approval for Alzheimer’s disease could be rapid. He added: “If scientists can demonstrate the efficacy of this treatment in phase 3 trials and the FDA approves it for Alzheimer’s disease, then this medicine could become available immediately.” Two independent phase 3 clinical trials are already underway, with results expected by the end of 2025.
