In January 1922, Leonard Thompson was a teenager dying of diabetes in a Toronto hospital. There was no cure for diabetes, and most adolescents succumbed to the disease within a year of diagnosis.

Thompson had endured diabetes for almost three years. The best physicians could advise was a near-starvation diet that reduced Thompson to only 65 pounds. His medical team agreed he was doomed. But then, Thompson received two injections of an experimental intervention— insulin. Within a day, his blood glucose levels stabilized. A lifesaving drug was born.

Soon, insulin was in mass production, and millions of lives were saved. The scientists credited with the discovery won a Nobel Prize. The victory, however, led to a lifelong animosity between the winners.

When was Insulin Discovered?

In 1922, physician Frederick Banting was teaching at the University of Toronto. He wanted to further test “pancreatic substances” as a way to treat diabetes. About 30 years earlier, scientists had discovered that insulin is produced in the pancreas and that people with diabetes lack the ability to make their own insulin.

Banting approached a scientist at the university, John Macleod, with his research interest. Macleod supported Banting and allowed him to work with one of his top students, Charles Best, and use his laboratory.

Together, Banting and Best began experimenting on dogs in May 1921. The dogs had their pancreases removed and were given a pancreatic extract injection, which proved to lower their blood glucose levels. By late 1921, J.B. Collip joined the research team and focused on purifying the insulin for human injection.

After Thompson received his life-saving injection, Macleod stepped in to help usher the drug to the mass market. Working with his contacts, he secured licensing and patents. He connected with the pharmaceutical company Eli Lilly to take the drug from being “thick brown sludge” that was tested on dogs to a regulated pharmaceutical found in every hospital’s medicine locker.

“And while none of these tasks might have the glitz and glamour of life-saving research, but without them, insulin would have got no further than the lab bench,” says Kersten T. Hall, the author of Insulin: The Crooked Timber and a visiting fellow at the University of Leeds in England.

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How Has Insulin Saved Lives?

The response was rapid. Eli Lilly began mass-producing insulin derived from cows and pigs. The formula saved millions of lives, but it had limits. Patients processed it quickly and required multiple daily injections to safely lower their blood sugar. There were supply issues as well as noted allergic reactions to the animal byproduct.

Novo Nordisk began producing a slower-acting insulin in 1936, which helped with supply issues because patients required less. The next big breakthrough came in the 1980s, when Eli Lilly introduced biosynthetic human insulin. Insulin from cows and pigs was no longer needed because a genetically engineered version was derived from E. coli bacteria.

Insulin saved diabetics’ lives. Currently, two million Americans have Type I diabetes, a number that includes 304,000 kids and adolescents. More than a century ago, diabetic children faced certain death,  and about 66 percent died within 1.4 years of their diagnosis. Advocates credit the scientists who discovered the life-saving drug and got it to market.

Problematically, the scientists disagreed as to who deserved the credit.   

Insulin Discovery Dispute

The 1923 Nobel Prize in Physiology or Medicine was given to both Banting and Macleod. Although Banting made the discovery, the committee believed insulin would not have made it to market without Macleod. Banting was not happy.

“He was furious; utterly livid,” Hall says. “Any sense of pride and achievement at having received the highest accolade in science was completely eclipsed by his sense of outrage at having to share the prize with Macleod.”

Banting felt he should have shared the prize with Best and that Macleod should have been excluded. Macleod felt that Collip, although a latecomer to the team, made essential contributions. Banting split his prize money with Best, and Macleod did the same with Collip.

The two prize winners parted ways. Macleod returned to his native Scotland in 1928 and died in his late 50s in 1935. Banting died in 1941 from injuries sustained in a plane accident.

Although the scientists’ feud was legendary, Hall says it’s important not to allow it to obscure how the scientific process leads to discovery.

“This is what, as historians of science, we’re here to do,” Hall says. “Not to undermine science, but quite the opposite – by exposing the flaws and oversimplifications of the popular legendary accounts, we reveal the practice of science to be much more complex – and so much richer and more interesting for it.”

This article is not offering medical advice and should be used for informational purposes only.

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Article Sources

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Emilie Lucchesi has written for some of the country’s largest newspapers, including The New York Times, Chicago Tribune and Los Angeles Times. She holds a bachelor’s degree in journalism from the University of Missouri and an MA from DePaul University. She also holds a Ph.D. in communication from the University of Illinois-Chicago with an emphasis on media framing, message construction and stigma communication. Emilie has authored three nonfiction books. Her third, A Light in the Dark: Surviving More Than Ted Bundy, releases October 3, 2023, from Chicago Review Press and is co-authored with survivor Kathy Kleiner Rubin.