Insulin injection saves diabetic patient. In Toronto, Leonard Thompson becomes the first diabetic to be treated with insulin. Diabetes had been known for over 3,000 years, but its precise cause remained a mystery until the 1920s. At the beginning of the 20th century, the only cure for this lethal disease was a diet low in carbohydrates and sugar but high in fat and protein, which extended the patient’s life by approximately a year. The revolutionary discovery occurred at the University of Toronto in the summer of 1921, where Canadians Frederick Banting and Charles Best extracted insulin from the pancreases of laboratory animals, producing the symptoms of diabetes, and subsequently injected the protein according to a schedule that restored the animals to normal. The experiment confirmed the theory that diabetes was caused by a deficiency of the substance needed to metabolize sugars. Assisted by other scientists, Banting and Best began treating Thompson with insulin extracted from the pancreases of slaughter animals. The boy improved significantly. Since 1923, insulin, now widely available, has continued to save the lives of countless people around the world.
