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Before 1922, a child diagnosed with severe diabetes had little hope. Doctors could only prescribe a near-starvation diet. Within about a year of the first injection, more than a thousand patients were being treated with insulin. This post tells how that happened, who did each part of the work, the famous disagreement over credit, and what you can learn from how the team got from a wrong first idea to a working medicine.
Who was Frederick Banting?
Banting was born on 14 November 1891 in Alliston, Ontario, and died in a plane crash in Newfoundland on 21 February 1941, according to his Nobel Prize biography. He studied medicine at the University of Toronto, served as a doctor in France in the First World War, was wounded at Cambrai in 1918 and won the Military Cross. By 1920 he was a doctor in general practice in London, Ontario, also teaching part-time at the University of Western Ontario.
What problem was Banting trying to solve?
Researchers already suspected that diabetes was caused by the lack of a hormone made by the islets of Langerhans in the pancreas. The name insulin had even been proposed. But, the biography explains, attempts to give patients pancreas or pancreas extracts had failed, presumably because the protein-digesting enzyme of the pancreas destroyed the hormone first.
Banting read an article by Moses Baron (as the Nobel biography spells it) reporting that when the pancreatic duct was tied off, the enzyme-making cells wasted away but the islets survived. His idea was to tie the duct, wait, and then extract the hormone from the surviving islets. He took the idea to J. J. R. Macleod, professor of physiology at Toronto, who gave him laboratory space, dogs and a student assistant: Charles Best.
What happened in the summer of 1921?
The University of Toronto's Discovery and Early Development of Insulin archive gives the timeline. Best, then 22, and a classmate reportedly tossed a coin over who would start first; Best won. The experiments began on 17 May 1921 in hot, cramped conditions, and early results were discouraging. The first clear success came on 30 July, when an injection of pancreatic extract lowered the blood sugar of a diabetic dog, number 410.
A review in Clinical Chemistry, Insulin: Discovery and Controversy (2002), adds a key point. The team soon developed a way to extract the hormone from whole pancreas, without tying the ducts, and moved to beef pancreas. Accurate blood sugar tests on small blood samples, a recent advance, made the work possible.
Who was the first patient?
The archive's patient histories record that Leonard Thompson, aged 14, weighed only 65 pounds when admitted to Toronto General Hospital in December 1921. On 11 January 1922 he received the first injection of pancreatic extract. It lowered his blood sugar but had little clinical effect. On 23 January he received a purer extract made by the biochemist J. B. Collip, and it worked. He lived 13 more years on insulin.
The team reported the first clinical results in March 1922 in the Canadian Medical Association Journal, under the names Banting, Best, Collip, Campbell and Fletcher. By early 1923, the archive notes, more than 1,000 diabetics were being treated by over 250 physicians in sixty clinics in the United States and Canada.
Why did the Nobel Prize cause a row?
The 1923 Nobel Prize in Physiology or Medicine went to Banting and Macleod "for the discovery of insulin." Rosenfeld's review describes Banting as outraged that Macleod, not Best, was chosen. He announced he would give half his prize money to Best. Macleod then gave half of his to Collip. Rosenfeld adds that the Nobel Committee's own later history admitted that Best should have shared the award.
There was more than ego here. Each person supplied something the others lacked: Banting the idea and drive, Best the daily lab work, Macleod the laboratory and physiological expertise, and Collip the purification that made a safe injection.
Where does insulin appear in your syllabus?
The NCERT Class 11 chapter on chemical coordination describes insulin as a peptide hormone made by the β-cells of the islets of Langerhans. It increases glucose uptake by liver and fat cells and so lowers blood glucose, while glucagon from the α-cells raises it. NCERT also notes that the islets make up only 1 to 2 per cent of pancreatic tissue, which helps explain Banting's problem: the hormone-making cells are a small fraction surrounded by enzyme-making tissue. Our guide to chemical coordination and hormones covers the full pathway. The structure of insulin was worked out decades later by X-ray crystallography, a story told in our post on Dorothy Hodgkin.
What can a student take from how the team worked?
Start with a testable idea. Banting's plan was specific enough to try in a lab.
Measure the result you care about. Blood sugar readings, not impressions, showed when the extract worked.
A failure can be a near miss. The first injection into Thompson did little; purification fixed it within two weeks.
Name everyone who helped. The credit row shows what happens when contributions are not recognised.
When a hormone pathway feels like a list of names to memorise, a clear explanation of each step helps it stick. The Fermi Concept Library covers every concept in biology, each with its own lesson.
Next step: draw the feedback loop for blood glucose after a meal, marking where insulin acts.
