How Toronto Researchers Won the Nobel Prize for Insulin Discovery

UPDATE - follow-up to Frederick G. Banting and John J.R. Macleod's Nobel-winning discovery of insulin: Frederick G. Banting and John J.R. Macleod won the 1923 Nobel Prize in Physiology or Medicine for discovering insulin, a hormone that controls blood sugar. Their work at the University of Toronto turned experimental physiology and clinical medicine into a life-saving treatment for a disease that was often fatal.

The Research Team

Banting, a Canadian doctor, approached Macleod in 1921 with a plan to isolate a blood sugar-regulating substance from the pancreas. Macleod provided lab space, animals, and guidance, while medical student Charles Best assisted with the experiments. The team tied off dog pancreatic ducts to preserve cell clusters called the islets of Langerhans, creating extracts that successfully lowered blood sugar in animals.

Clinical Success

Biochemist James Collip joined in 1922 to purify the extract for humans. In January 1922, 14-year-old Leonard Thompson became the first human patient to receive insulin at Toronto General Hospital. After initial impurities caused an abscess, a purer dose successfully lowered his blood glucose and improved his health. Banting shared his prize money with Best, and Macleod shared his with Collip to honor their key roles.

Context

This discovery transformed diabetes from a condition managed only by strict, short-term diets into a manageable state using hormone replacement. Modern treatments continue to rely on these foundational discoveries about beta cells and glucose regulation.