Inflammation, which is highly prevalent in those with chronic metabolic diseases, is one of the hallmarks of both Alzheimer's and Parkinson's.

"One of the really interesting things about the GLP-1 drugs is that beyond the control of blood sugar and body weight, they also seem to reduce the complications of chronic metabolic disease," said study co-author Daniel Drucker, a professor in the department of medicine at the University of Toronto. "We know from clinical studies that GLP-1 does all this amazing stuff in people, but we don't fully know how it works."

Glucagon-like peptide-1 (GLP-1) receptor agonists have become the most talked-about medical-science development since mRNA vaccines. Semaglutide and tirzepatide, known under brand names such as Ozempic, Wegovy and Mounjaro, were first used to effectively treat type 2 diabetes, but have since found fame as a new, highly touted class of weight-loss medication.

Drucker and team believed that this wasn't the limit of their 'superpowers', and were keenly interested in the relationship between inflammation and GLP-1 drugs. What the researchers found was a new, fascinating and potentially life-changing interaction with other organs, but particularly the brain.

"The strange thing is that you can't find many GLP-1 receptors in all these other organs where GLP-1 seems to work," said Drucker, whose earlier work opened the door to the development of drugs including Ozempic and Wegovy.