The discovery of insulin was one of the most significant medical breakthroughs in history, saving millions of lives and transforming healthcare for people with diabetes. It marked the start of a century of evolution and new discoveries, replacing earlier treatments such as greatly restricted diets, that had limited success.
Although the symptoms of diabetes were first noted by physicians around 3,500 years ago, it wasn’t until the 20th century that the medical breakthrough of insulin changed lives.
What is diabetes?
Currently, more than 5.8 million people in the UK have diabetes, which occurs when a person’s blood sugar is too high. Our main source of energy, glucose is created by the body and also comes from the food we eat. The pancreas makes the hormone insulin to help glucose enter cells and create energy.
The NHS advises people should visit their GP if they experience any potential symptoms including feeling very thirsty, urinating frequently, being tired all the time, losing weight and muscle tone, blurred vision or frequent episodes of thrush.
What does insulin do?
For people with diabetes, the body doesn’t make enough insulin, or doesn’t use it properly, meaning it stays in the blood and fails to reach cells. This can cause health issues over time, risking damage to the kidneys, eyes, heart and nerves and a shortened lifespan.
There are two main forms of diabetes: type 1 occurs when the body’s immune system destroys insulin-producing cells, while type 2 is when not enough insulin is produced, or the body’s cells don’t react properly. Type 2 is more common in the UK, affecting 90% of all diabetic adults.
Many people may have type 2 diabetes for years without realising, as mild symptoms may not be detected. Type 1 can develop rapidly over a period of days or weeks.
History of diabetes treatments
Historians in the 19th century discovered Egyptian medical documents written on ancient papyrus that gave an insight into how our ancestors treated various health conditions. Physicians in Ancient Egypt first identified symptoms of diabetes in around 1500 BC, when patients were recorded as losing weight and urinating frequently. However, it was a rare condition, with no treatments or cures.
The first accurate description was made during the second century AD by Greek physician Aretaeus of Cappadocia, who wrote down his findings. Modern medical experts recognise his thinking as being way ahead of its time, anticipating 19th and 20th century ideas on medicine. He coined the term “diabetes” from the Greek word “diabaino”, which translates as “pass through”. This reflects a symptom of the disease, the need to urinate frequently, referring to fluids passing through the body.
Historic treatments for diabetes included strict diets, fasting and low carbohydrate diets to reduce the amount of blood sugar. These weren’t cures, but were aimed at extending the patient’s life. In the 19th and early 20th centuries, several proprietary medicines said to treat or cure diabetes appeared on the market. Some had been invented to treat kidney disease and urinary-related problems, while others were marketed as specific diabetes medication, such as Warner’s Safe Diabetes Cure. Usually, the formulas were kept secret, but the ingredients commonly included bromides, opiates, arsenic and pancreatic extracts.
The lack of effective treatment impacted the lifespan and quality of life of people with diabetes, who often had a shortened life and suffered problems due to excessive urinating and vision impairment. Those on strict diets often fared no better and shocking reports surfaced of some having malnutrition as a result. Once the symptoms of diabetes were diagnosed, patients had a life expectancy of only one to two years, even with dietary restrictions. Between 1897 and 1914, the mortality rate for type 1 diabetes was 824 per 1,000 people.
Who discovered insulin?
In the early 20th century, scientists all over the world were conducting research into finding a diabetes cure, but it wasn’t until November 1920 that a number of great minds came together to find a definitive healthcare solution. By this time, research had already discovered that clusters of cells known as islets in the pancreas produced insulin, but these were destroyed in cases of type 1 diabetes. The challenge they faced was how to safely extract insulin from pancreas cells without causing damage.
Canadian surgeon Frederick Banting read a medical article in October 1920 that suggested cells that produced insulin deteriorated slower than other pancreas tissue. Based on this theory, he began considering ways of removing insulin from the cells. On 7th November 1920, he met with Toronto University professor John Macleod and they combined their knowledge and skills to work on a healthcare plan. In May 1921, they were joined by research student Charles Best, who specialised in checking glucose levels in patients through blood tests.
How was insulin discovered?
Dogs with diabetes symptoms were tested regularly as part of the research and scientists found a way of isolating insulin from the pancreas. Once this was achieved, one dog with life-threatening diabetes was kept alive for more than 70 days as a result of being treated with extracted insulin. Blood glucose levels returned to normal. The process was refined using insulin from the pancreas of cattle.
Canadian biochemist James Collip joined the team and refined the bovine insulin until scientists were ready for their first human patient, 14-year-old Leonard Thompson, of Toronto. Following insulin injections on 11th and 23rd January 1922, despite having been close to death, Thompson began to recover and lived until April 1935.
After the scientific find was released for public use, the medical breakthrough led to Banting and Macleod receiving the Nobel Prize in Medicine in 1923. In April 1923, insulin was made available in the UK, with the first British patient being the Sheffield industrialist Sir Stuart Goodwin. The treatment rapidly transformed diabetes care and reduced mortality rates - by 1926, they were down to 19 in 1,000 patients and by 1938, it was further reduced to eight in 1,000.
How has insulin treatment evolved?
Over the years, treatment has further evolved, with refined insulin from cattle and pigs gradually being replaced by synthetic “human” insulin first produced in 1978. In 1982, the first commercially available human biosynthetic insulin was released under the brand name Humulin.
Now available in many forms, treatments include regular insulin identical to that produced by the human body, and ultra-rapid and long-lasting insulins that can be prescribed based on individual needs and lifestyle. Literally a life-saver, insulin is crucial in the proper management of diabetes.
The risks of poor diabetes management can have serious consequences for patients, with healthcare supplies playing a key role in successful treatments. High quality hygiene supplies such as PPE, gloves and sterile equipment are used to prevent contamination and bacteria. Devices like insulin pumps, blood sugar meters and diabetic test strips are an integral part of the armoury used by healthcare professionals and patients to manage the condition.
Insulin is recognised as a true medical marvel.
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