Today marks the 24th installment in a series of articles by titled, Heroes of Progress. This bi-weekly column provides a short introduction to heroes who have made an extraordinary contribution to the well-being of humanity. You can find the 23rd part of this series here.

This week our heroes are Frederick Banting and Charles Best, the two scientists who created the first effective treatment for diabetes by successfully extracting the hormone insulin from the pancreas. Thanks to Banting and Best’s work, millions of diabetics can now live long, healthy lives rather than face early, painful death.

Diabetes is a disease that causes a person’s blood sugar levels to become too high. Its symptoms include excessive thirst, nausea, fatigue, sugary urination and weight loss. If left untreated, diabetes can lead to complications that include strokes, kidney failure, heart attacks and nerve damage. Diabetes has plagued humanity for thousands of years, but even a century ago there were no effective treatments. Enter, Frederick Banting and Charles Best.

Frederick Banting was born on November 14, 1891 in his family’s farmhouse near Alliston, Ontario. In 1912, Banting started studying medicine at Victoria College, a part of the University of Toronto. He joined the Canadian army in 1915 and graduated a year later. In 1918 he was wounded at the Battle of Cambrai and in 1919 he was awarded the Military Cross for heroism under fire.

After the war, Banting returned to Canada and studied orthopedic medicine. From 1919 to 1920, he was Resident Surgeon at the Hospital for Sick Children, Toronto, and in 1921 he began lecturing in pharmacology at the University of Toronto. During this time, Banting became interested in diabetes.

Before the 1920s, it was known that diabetes resulted from a lack of a hormone called insulin, which is made in the pancreas. It was thought that insulin controlled the metabolism of sugar. Lack of insulin, people believed, led to an increase of sugar in the blood.

Unfortunately, previous attempts to extract insulin from the pancreas failed because trypsin, the pancreas’ own digestive enzyme, would break down the pure insulin before it could be extracted. Banting had to find a way of extracting the insulin from the pancreas, before it could be destroyed by the organ’s own digestive enzyme.

Banting read about a 1920 experiment by Moses Barron, a Russian-American scientist who closed the pancreatic duct and found that the cells that secreted trypsin, the digestive enzyme, deteriorated, but the cells in the pancreas that are responsible for the production and release of insulin remained intact. This led Banting to theorize that if the pancreatic duct were closed and the trypsin-secreting cells died, insulin could be extracted from the pancreas and then given to diabetics.

In the spring of 1921, Banting visited J. J. R. Macleod, a professor of physiology at the University of Toronto, to discuss his theory. After a lengthy discussion Macleod agreed to give Banting laboratory space and ten dogs to experiment on. Macleod then appointed Charles Best as Banting’s assistant.

Charles Best was born in West Pembroke, Maine on February 27, 1899. In 1915, Best began studying physiology and biochemistry at the University of Toronto. He enlisted in the army in 1918 and, after the war, completed his degree in 1921. In the same year, he began studying at the University of Toronto’s medical school.

Banting and Best started working together and were quickly successful in isolating the insulin from the test dogs’ pancreases. After injecting the insulin into dogs whose pancreases had been removed, they found that the dogs who were suffering from their artificially induced diabetes quickly recovered.

Animal insulin is safe for human use, and Banting and Best began taking insulin from the larger pancreases found in cows. However, they encountered problems refining the insulin solution and Macleod hired James Collip, a professor of biochemistry at the University of Alberta, to work on the purification of insulin.

In January 1922, Banting and Best administered purified insulin into their first ever patient, Leonard Thompson, a 14-year-old diabetic who was close to dying. Best and Banting’s insulin proved to be a success as Thompson regained his health. The use of insulin to treat diabetes quickly spread throughout the world.

Banting received his M.D. in 1922 and in 1923, Banting and Macleod were jointly awarded the Nobel Prize in Physiology or Medicine. Banting was unhappy that Macleod who, in Banting’s view, had contributed nothing more than resources, was awarded the prize. As a result, Banting split his prize money with Best. Macleod similarly split his prize money with Collip.

In 1923, Banting was elected chair of the new Banting and Best Department of Medical Research, which was endowed by the Legislature of the Province of Ontario. His research focused on silicosis and cancer. In 1925, Best was awarded his M.D. and in 1929, he succeeded Macleod as professor of physiology at the University of Toronto.

In 1938, Banting started working for the Royal Canadian Air Force, researching the physiological problems encountered by pilots flying high-altitude aircraft. On February 21, 1941, Banting died of wounds following an aircraft crash in which he was a passenger. Following Banting’s death, Best took over as Director of the Banting and Best Department of Medical Research. Best spent most of his career investigating carbohydrate metabolism, he retired in 1965 and eventually died on March 31, 1978.

Banting and Best received numerous awards and honorary degrees throughout their lives. Both men were members of numerous medical academies. In 1994 they were inducted into the Canadian Medical Hall of Fame. In 2004, both men were inducted into the National Inventors Hall of Fame.

Thanks to the work of Frederick Banting and Charles Best, diabetes went from an untreatable condition that has killed untold millions of people over thousands of years to a disease that can be easily treated, thus enabling diabetics to lead normal, healthy lives. For those reasons, Frederick Banting and Charles Best are our 24th Heroes of Progress.

PS: Charles Best is on the left of our cover picture and Frederick Banting is on the right of our cover picture.