The Discovery of Insulin

The Discovery of Insulin
1921 A.D.Banting and Best discover that insulin is secreted from the islet cells of the pancreas. The discovery of insulin was one of the most dramatic events in the history of medicine; it overshadows everything else in the story of diabetes. Frederick Banting was an unsuccessful orthopaedic surgeon who, on reading of the association of the destruction of the pancreas with diabetes, became convinced that he could find the antidiabetic substance. He was so ignorant that he did not know how many other people had tried in the 40 years since Minkowski. That was Banting’s strength; he did not realise how difficult the problem was. Nothing would stop him. He persuaded J.J.R. Macleod, the Professor of Physiology at Toronto who did understand the problem and its difficulties, to let him try. Macleod assigned a young medical student, Charles Best, to work with him and later (when the process of extraction and stability of the pancreas secretion was proving difficult) he put a visiting professor J.B. Collip, a biochemist, on to the problem with dramatic results.

Banting's original idea had been that it was the external secretions of the pancreas which destroyed the 'insulin'. So he tied off the pancreatic duct, waited some weeks for the glandular part of the pancreas to atrophy, and then made an extract of the remaining gland. In the end this logical process proved not to be effective and insulin was obtained by standard chemical methods of extraction. Finally, an extract was made which could be tried on patients. It had a dramatic effect. For the first time levels of blood glucose were lowered. Young patients who had been slowly dying of their diabetes lost their consuming thirst, recovered their strength and regained their lost weight. It was a miraculous transformation. A universally fatal disease had been controlled; so long as they took their daily insulin injections, patients could be restored to normal life.

We can easily forget today, when insulin treatment is universally available and successful, what type I diabetes meant before this discovery. Death was a slow one. Some of those youngsters who were the first to be treated with insulin had been wasting away for years, losing ground all the time but kept alive by ferocious dieting. 'Dieting' meant starvation. This early method of treatment was the only way to control blood sugar levels. Early diabetologists such as Elliott Joslin in Boston and Frederick Allen in New York were very strict with this dietary approach and they had to be. They had nothing else to offer but diet. If the patient got an infection and the diabetes got worse, the answer was an even stricter diet. It was a miserable situation for diabetics and heart breaking for the parents of these children.