On this date at the University of Toronto, Canadian scientists Frederick Banting and Charles Best successfully isolated insulin from canine test subjects — a hormone they believed could prevent diabetes — for the first time. On November 14, following successful trials on diabetic dogs, the discovery was announced to the world.
At that time, the only way to treat the fatal disease was through a diet low in carbohydrates and sugar and high in fat and protein. Instead of dying shortly after diagnosis, this diet allowed diabetics to live — for about a year.
On 11 January 1922, Banting and Best gave 14-year-old Leonard Thompson an injection of a reasonably pure extract of insulin from the pancreases of cattle from slaughterhouses. His blood sugar levels dropped significantly, but an abscess developed at the injection site making him acutely ill. A refined extract was again administered on 23 January, causing a drop in blood sugar levels from 520 mg/dl to 120 mg/dl within 24 hours. Leonard lived for 13 years, taking doses of insulin, before dying of pneumonia (another disease for which no cure was available in those days).
Within a year of isolating the hormone, the first human sufferers of diabetes were receiving insulin treatments, and eventually countless lives were saved from what was previously regarded as a fatal disease. By early 1923, insulin had become widely available, and Banting and Macleod were awarded the Nobel Prize in Physiology or Medicine for that year.
- F. G. Banting, C. H. Best, J. B. Collip, W. R. Campbell, and A. A. Fletcher. Pancreatic extracts in the treatment of diabetes mellitus. Preliminary report. Can Med Assoc J vol. 12 no. 3: 141-146 (March 1922).
- Louis Rosenfeld. Insulin: Discovery and Controversy. Clinical Chemistry vol. 48 no. 12: 2270-2288 (December 2002).