In November 1921, insulin was discovered as a revolutionary treatment for diabetes, transforming diabetes from a death sentence to a manageable chronic condition. Dr. Frederick Banting from London, Ontario, and his medical assistant Charles Best co-discovered insulin on 14 November 1921. The discovery marked a significant breakthrough in medicine and therapy for patients with diabetes, effectively saving the lives of millions and standing to this day as the most effective treatment for Type 1 diabetes.
Prior to the extraordinary discovery, Type 1 diabetes would almost inevitably result in death. During the early twentieth century, physicians commonly endorsed near-starvation, calorie-restricted diets, and fasting, resulting in marginal improvements of glucosuria and acidosis, often only delaying death among diabetes patients. However, even as recently as 1920, patients were given mere weeks to live once diagnosed with diabetes, often entering diabetic ketoacidosis (DKA) and dying soon after their diagnosis.
Before Banting and Best’s discovery, the role of the pancreas in secreting a substance controlling the metabolism of carbohydrates was only hypothesized. In 1896, Paul Langerhans, a German medical student, discovered a cluster of cells in pancreatic tissue whose function, at the time unknown, produced insulin. Following this development, in 1889, two German medical researchers evaluated the effects of removing a dog’s pancreas, subsequently discovering that the removal provoked severe symptoms of diabetes. With this discovery of an immediate cause of diabetes and the hypotheses on developing insulin’s role in treating diabetes, Frederick Banting and Charles Best entered the medical world.
Researchers had previously hypothesized and made critical efforts to isolate and extract insulin, which was unsuccessful due to toxicities and impurities. Frederick Banting, an orthopedic surgeon, approached John Macleod, professor and department head of Physiology at the University of Toronto, with the idea of isolating pancreatic islet extracts by ligating the pancreatic ducts of dogs. Professor Macleod granted Banting a medical assistant (Charles Best), laboratory space, and ten dogs for his experiments. Banting’s procedure involved removing a dog’s ligated pancreas and injecting the dog with intravenous injections of their pancreatic extract, termed isletin, which effectively lowered the dog’s blood glucose level. With help from James B. Collip and Professor Macleod to purify the extract for human use, the first injection was successfully administered in 1922. In 1923, Frederick Banting won the Nobel Prize in medicine for the discovery, marking the first time a Canadian was awarded such recognition.
Subsequent developments of the treatment have improved diabetes control while concurrently reducing and delaying complications. As newer medications continue to complement and enhance the treatment, insulin remains a cornerstone of therapy for diabetes mellitus, and to this day, serves as the safest and most effective way of managing blood glucose levels. As researchers and medical experts seek new and innovative treatments for diabetes, Banting and Best’s discovery revolutionized the management of diabetes, successfully transforming the lives of millions of diabetes patients and serving as a springboard for future diabetes technologies.