According to the World Health Organization’s (WHO) fact sheet on diabetes, the number of people with it has increased from 108 million in 1980 to 422 million in 2014. In fact, the WHO projects that in 2030, diabetes will be the seventh leading cause of death. While those numbers might be alarming, it gives us an opportunity to understand the threat that diabetes possesses.
Though diabetes is one of the first human diseases on record and has been recognised as a medical condition for more than 3,000 years, its exact nature had been a mystery till the 20th century.
We now know that diabetes is a chronic disease that occurs either when the pancreas in our body doesn’t produce enough insulin or when the body is unable to effectively use the insulin that it produces.
Link with pancreas
Towards the end of the 19th century, it had been determined that the complete removal of pancreas in dogs resulted in severe diabetes in the test subjects. Scientists hypothesised that the pancreas controlled the glucose metabolism by producing a hormone, which was named as “insulin”. So when the pancreas malfunctioned and hence couldn’t produce enough insulin, blood sugar level rises, leading to a number of complications.
There were repeated efforts to extract insulin from pancreas, but all these ended in failures. It was under these circumstances that Canadian physician Frederick G. Banting, who had become deeply interested in diabetes, entered the fray.
Banting has an idea
Having read in a medical journal about how the islets of Langerhans remained intact even when the pancreatic duct had been experimentally closed using ligatures, Banting had an idea for extracting insulin this way. He discussed this with many people and finally found a backer in J.J.R. Macleod, Professor of Physiology at the University of Toronto.
Determined to make his idea into reality, Banting set to work in the facilities afforded to him. He was joined by an assistant in the form of Dr. Charles H. Best, who was then a medical student. Along with Best, Banting began his intensive effort to isolate insulin.
Breakthrough in 1921
They had their breakthrough in the summer of 1921 when they successfully isolated insulin from canine test subjects. This they did by using ligatures to tie off the pancreatic ducts of the dogs, reducing the pancreas to inactivity. While this led to the degeneration of the trypsin-secreting cells that are essential for protein digestion, the islets of Langerhans, believed to be the site of insulin production, remained intact. When solutions extracted from these cells were injected into the dogs, they returned to normalcy, recovering from their artificially induced diabetes.
The discovery was made on July 27, 1921 and was announced to the world on November 14, the same year. They enlisted James B. Collip, a young biochemist, to help them purify the insulin that they were able to obtain.
Thompson subjected to the first human test
Their first human test took place a couple of months later in January 1922. Leonard Thompson was a 14-year-old with Type 1 diabetes, and had little time to live. From the pancreas of an animal, Banting and Best were able to extract insulin, which was then purified to a reasonable extent by Collip.
The insulin injections had a dramatic effect on Thompson’s health and his blood sugar levels stabilised soon. In fact, with insulin doses to supplement his health, Thompson was able to live for another 13 years, before eventually succumbing to pneumonia.
The University of Toronto, on their part, gave the licence to produce insulin in this manner to pharmaceutical companies, without any royalties. On April 15, 1923, insulin became commercially available and went on to save tens of thousands of diabetics from certain death (the existing treatment before the isolation of insulin involved taking a strict diet low in carbohydrates and sugar, and high in protein and fat – allowing** the diabetic to survive for less than a year).
Splits Nobel Prize
In that same year, the Nobel Prize for Physiology or Medicine was awarded to Banting and… wait for it… Macleod. Banting was upset that Macleod, rather than Best, was being recognised and rewarded for their work and therefore divided his share of the prize money equally with Best. Macleod, meanwhile, shared his portion of the Nobel Prize with Collip.
Insulin extracted from animals was the norm for decades, even though it did have allergic reactions for some users. Synthetic insulin came in the second half of the 20th century, and it further improved the treatment for diabetics.
