27 July 1921: Banting and Best Isolate Insulin
On July 27, 1921, at the University of Toronto, Canadian scientist Frederick Banting and his assistant Charles Best successfully isolated insulin from the pancreas of a dog, achieving a breakthrough that would transform diabetes from a death sentence into a manageable condition and save countless millions of lives.
Before the discovery of insulin, a diagnosis of Type 1 diabetes was essentially a death warrant. The disease, which prevents the body from producing insulin needed to regulate blood sugar, led to a slow and agonizing decline. Patients were placed on starvation diets that could extend life by a few months or years but left them weak and emaciated. Children diagnosed with diabetes rarely lived more than a year.
Banting was an orthopedic surgeon with limited research experience when he conceived his idea for extracting insulin. Reading about diabetes research one night in October 1920, he theorized that previous attempts to isolate the hormone had failed because digestive enzymes in the pancreas destroyed the insulin before it could be extracted. He proposed tying off the pancreatic duct to cause the enzyme-producing cells to atrophy while preserving the insulin-producing islet cells.
The established diabetes researcher J.J.R. Macleod was skeptical but provided Banting with laboratory space and the assistance of Best, a young medical student with training in blood sugar testing. Working through the summer of 1921 with minimal resources, Banting and Best conducted their experiments on dogs. On July 27, they successfully extracted pancreatic material that dramatically lowered blood sugar in diabetic dogs.
The transition from laboratory success to clinical treatment came remarkably quickly. In January 1922, a 14-year-old boy named Leonard Thompson became the first human patient to receive insulin injections. Though the initial dose caused an allergic reaction, a purified version developed with the help of biochemist James Collip proved effective. Thompson, who had been near death, recovered and lived another 13 years.
Banting and Macleod received the Nobel Prize in Physiology or Medicine in 1923, just two years after the initial discovery. Banting shared his prize money with Best, and Macleod shared his with Collip. In a remarkable act of generosity, Banting and his colleagues sold the insulin patent to the University of Toronto for one dollar, believing that a life-saving medicine should be available to all who needed it.
