From the archives: How a medical ‘outsider’ discovered insulin

To mark our 150th year, we’re revisiting the Popular Science stories (both hits and misses) that helped define scientific progress, understanding, and innovation—with an added hint of modern context. Explore the entire From the Archives series and check out all our anniversary coverage here.

At the time insulin was developed into a life-saving serum, the world was still recovering from The Great War’s 40 million casualties, silent movies were the rage, Ford’s Model T topped auto sales, and 22 of 100,000 New Yorkers were dying of diabetes. The disease kills the pancreas’s insulin-producing islet cells, or Islands of Langerhans. 

Also in 1920s America, medicine—the kind taught in universities and practiced in cloistered institutions—was the almost exclusive province of wealthy white men. In September 1923, when Popular Science hailed the discovery of insulin as a modern medical miracle, it’s no surprise the magazine (already a half-century old) chose to spotlight the farm-boy pedigree of insulin’s discoverer, Frederick Grant Banting, a young Canadian doctor who was considered an outsider in research circles. “‘No one had ever heard of him,’” Donald Harris wrote for Popular Science, quoting a New York City M.D. “‘This young doctor didn’t know much about diabetes. Quite by chance he discovered how to get insulin and use it as a cure.’”  Not only was Banting an outsider, but his early methods were also viewed critically. He made progress extracting insulin from animal entrails in a nonconforming lab, set up at the home of college friend in Toronto.

A century after insulin was first administered in trials, diabetes remains a killer, ranked 8th in 2020 by the CDC, taking lives at a faster clip than before its discovery. That’s because diabetes, specifically Type 2, has soared in the US, and not everyone can afford life saving treatments. Even in 1923, doctors understood that insulin was only a stopgap and that a cure would still be needed. In what now seems like an omen directed at the 21st century, Harris wrote, “the medical profession has issued a warning that [insulin] is not to be regarded as a magic or instant cure. In fact, it is not a ‘cure’ at all, since it does not destroy the causes of the disease.” 

Even with artificial pancreases, coaxing other organs to grow insulin, and monoclonal antibodies, a cure remains elusive. By the efforts of another nonconforming lab—one that  employs highly restricted human embryonic stem cells—a century after Banting’s insulin-treatment discovery, a diabetes cure may be closer than ever. 

“Insulin—a miracle of science” (Donald Harris, September 1923)

How a young laboratory assistant won world fame by discovering serum that offers relief to millions of diabetes sufferers

From six hospitals in the United States a few weeks ago came some news that electrified the scientific world. A serum derived from the entrails of animals, given to the hospitals for clinical test of its efficacy as a treatment for diabetes, had proved so extraordinarily successful in administration to many hundred patients, that the physicians who conducted the tests asserted without qualification that it appeared to be a sure method of controlling the disease. 

What “insulin” means

The new serum is insulin, a name derived from the Latin word meaning “island.” This name was applied because the particular groups of intestinal cells from which the serum is extracted are known in medicine as the “Islands of Langerhans.”

Since the first announcement of the successful tests of insulin, eminent medical men have been almost a unit in declaring that through its general use probably will be sounded the death knell of diabetes, a disease which until now has resisted the best efforts of medical science. Dr. Simon Flexner, director of the Rocks feller Institute for Medical Research, has said that insulin promises to prove “one of the great medical contributions to the world.”

Dr. A. I. Ringer, in charge of the test of insulin at the Montefiore Hospital in New York, stated unequivocally that “insulin is undoubtedly one of the greatest discoveries of the age,” and that, now that it has been given to the world, “no person should die of diabetes.”

Dr. Nellis B. Foster, writing in the “New York Medical Journal,” declared, “I think it is safe to say that could one start with insulin before operation, one could be reasonably sure that the patient would not die of diabetes.”

Other medical authorities expressed their endorsement of the new serum with equal enthusiasm, and John D. Rockefeller, Jr., only a few weeks ago contributed $150,000 to permit 15 hospitals in the United States to introduce the use of insulin in their clinics.

Probably the most amazing and dramatic feature of this remarkable discovery is the personality of its discoverer. The man who gave insulin to mankind was no famous medical authority, nor was he even a recognized scientist, trained in the intricacies of research, fortified by exhaustive knowledge of medical lore, and possessing extraordinary equipment in laboratory and materials. Instead, he was an obscure Canadian doctor of 31, less than six years out of medical college, a farmer’s son, who had accepted with pride a humble position as a laboratory assistant in a Canadian university when he returned wounded from war service only three years ago.

Moreover, the most valuable part of the discoverer’s work was accomplished in the incomplete home laboratory of a young Toronto doctor, a school friend, who permitted him the use of his home and equipment merely because he, the owner, was going away on a vacation and had no use for them.

The discoverer of insulin is Dr. Frederick Grant Banting. Probably I there is no better illustration of the general attitude of the medical profession toward him and his discovery than the recent comment of Doctor Flexner:

Where experts failed

“No one had ever heard of him. In fact, there was no reason why anyone should have heard of him.

“This young doctor didn’t know much about diabetes. Quite by chance he discovered how to get insulin and use it as a cure. At Toronto he proved the efficacy of his treatment. We experienced physicians who had so much material and so much scientific background to help us find a cure for diabetes, failed. We feel like kicking ourselves.

“The world is enormously richer today as a result of Doctor Banting’s discovery of insulin. It seems to me that mankind never again will be in the grip of this disease as it has been for so long. There is still a bit of danger in its use, but some day we shall all know just how to administer it. Then all the world, every hamlet of it, will appreciate the benefits.”

In speaking of “chance” as a factor in Doctor Banting’s discovery, Doctor Flexner had no intention of belittling either the discovery or the discoverer. The truth is that in what Doctor Banting has accomplished, chance played a prominent part, and no one is more ready to admit the fact than he.

Diabetes is caused by the failure of the Islands of Langerhans properly to perform their functions. In the normal man these “islands” secrete insulin—the same insulin which now is taken from animals to supply a means of fighting diabetes.

Carbohydrates—foods of a starchy sort —are converted into sugar, which is absorbed by the intestines. Part of the sugar is carried to the liver, where it is stored as glycogen, or animal starch. The remainder is carried by the blood to the muscles and other tissues, where some of it is oxidized and some stored as glycogen.

Insulin secreted by the normal man passes directly into the blood, there combining chemically with the sugar substances formed from food to supply the body with elements necessary to the health. In diabetes, the insulin fails to perform its chemical action on the sugar substances. This causes them to circulate in large quantities through the blood and to be lost in excretions. The body, in consequence, is deprived of an important source of energy. Among the symptoms of the disease are voracious appetite and abnormal presence of sugar in the blood and certain bodily excretions.

What causes diabetes

The medical profession long had known that the removal from an animal of the Islands of Langerhans resulted in symptoms of diabetes. Also, marked destructive changes in the “islands” were noted in the majority of patients who suffered from diabetes. The conclusion, of course, was that a derangement of secretions from the “islands” was the cause of the disease. Investigators had arrived at the belief that extracts of the secretions from the “islands” obtained from animals might supply a serum, which, by supplying to diabetics the insulin which nature was failing to produce, would form an effective treatment for the disease.

Langerhans, the German physician for whom the “islands” are named, and others had expressed this opinion in treatises, but attempts to obtain pure insulin proved futile, since it was destroyed invariably by the powerful digestive ferments present in the extracts which were made.

Dr. Banting begins research work

In November, 1920, Doctor Banting, having chanced upon Langerhans’s work on the subject of diabetes, became interested in the possibility of developing the serum, and began experimenting at the laboratories of Western University, where he had been a laboratory assistant for a few months. He discovered this work to be so engrossing that he applied for a two months’ leave of absence and set up a laboratory at the home of Dr. F. W. Hipwell in Toronto. Doctor Hipwell was a school and college friend, who was leaving the city for a vacation. The two months’ leave was extended to three, and at the end of that time Doctor Banting resigned from the university, for his experiments were progressing with encouraging success.

In attempts to extract pure insulin from the intestinal tracts of animals, previous experimenters had shown that by tying up the ducts from whence came the digestive juices, degeneration occurred much more rapidly in the juices than in the Islands of Langerhans. After many months of work, Doctor Banting conceived the idea that if an extract were prepared from the intestinal tissue remaining, some time after the ducts had been tied, it should contain insulin because there would not be enough of the digestive ferments to destroy it.

In I921 his experiments in this line proved successful; he obtained the serum he sought in a comparatively pure state and devised methods of refining it further, in moving from it substances that rendered it unsuitable for repeated injection in man.

By this time his experiments had reached a stage that led the authorities of the University of Toronto to permit him to pursue his work in the famous Connaught Laboratories. It was from there, after several months intensive work to determine the effect of insulin on normal and diabetic animals, that the announcement was made that the Banting serum was ready to be offered to the medical profession for clinical test. In his work at the university, Doctor Banting was assisted by Dr. J. J. Leod, Dr. C. H. Best, and others.

Successful tests in United States

The results of the tests of insulin conducted in six hospitals in the United States, have been entirely successful. Previous to the introduction of insulin, the accepted treatment for diabetes was dietetic—limiting the quantities of starches and sugar taken in food. This method of treatment was unsatisfactory, since the inadequate diet resulted in great loss of strength and energy, and since lapses from the severity of the prescribed diet resulted in recurrence of the diabetic symptoms.

Using insulin, physicians now are able to permit their patients a strength-sustaining diet during treatment. The serum, which usually is injected in the arm, restores to the body its normal power of transforming starches, sugar, fats, and similar food into the chemical constituents necessary for health.

Many of the patients whom the clinical directors pronounced cured of diabetes by insulin had been in a diabetic coma from which only a handful of sufferers ever had emerged previously. Five who had been in this last stage of the disease were treated and discharged at the Montefiore Hospital alone.

Robert Lansing is aided by insulin

Prominent among those whom insulin has helped is Robert Lansing. former Secretary of State, who had been suffering from diabetes for years. Recently he stated that, after six weeks’ treatment with insulin, he was well on the road to recovery.

Just how important Doctor Banting’s discovery is to the health of the nation is shown by mortality statistics recently published by the United States Census Bureau. These reveal that for 20 years the number of deaths from diabetes has been increasing steadily in the United States with a really startling increase since 1919.

In New York State the rate of mortality from diabetes is highest—22 in 100,000. New Jersey, Pennsylvania and Ohio also show very high rates, while in the West and South, deaths from this disease are comparatively few. The variations are due, not to differences in climate, it has been explained, but to the recognized varying susceptibility to diabetes of different classes of the population. [Editor’s note: Parts of the following phrasing have been edited for sensitivity.] Thus, older persons are more prone to contract the disease than the young; white persons are more susceptible than non-whites; women are more susceptible than men. Among the white nationalities, Irish and Jewish populations show an especial susceptibility, and the death rate from the disease consequently is large in states where these two groups make up a large portion of the population. Estimates as to the number of diabetics in this country vary between 500,000 and 2,000,000.

Despite the undoubted success of insulin, the medical profession has issued a warning that it is not to be regarded as a magic or instant cure. In fact, it is not a “cure” at all, since it does not destroy the causes of the disease. It is a remedy, merely supplying to the body an element that disease has removed. Injections of insulin every day for long periods are necessary to successful treatment. Stopping the treatment, it is said, causes the disease to reappear.

A high degree of skill is necessary in the administration of insulin. The quantity to be injected varies according to the proportion of sugar in the patient’s blood, and an overdose of insulin, medical authorities say, may result in serious complications.

Meanwhile Doctor Banting, lifted suddenly from obscurity to worldwide fame, remains, so his intimates say, the same unassuming, serious-minded, diffident young man he was when he returned from the war, wounded and wearing the Military Cross, to begin his professional life in Toronto. The people of Alliston, Ont., where live his father and mother, each past the threescore-and-ten mark, and his brothers and sisters, take immense pride in the fact that he has become the town’s most noted son. He still speaks of Alliston as “home.”

Began life as a farm boy

Before leaving Alliston 12 years ago to enter the University of Toronto, Doctor Banting was a farm boy, performing chores around his father’s homestead like hundreds of other boys in the agricultural sections of Canada. His teachers say that he made no particular mark in his studies, although he was studious and persevering. Up to the time he left there to study medicine, most of the people in Alliston believed he intended to enter the ministry. Immediately after graduating from medical school, he entered the Canadian army, becoming a battalion physician with the rank of captain. He was wounded at Cambrai and invalided to England, where he remained until 1920.

Referring to this incident of his career in the army, his mother recently furnished an illuminating sidelight on his character. “He made a promise that he would write to me every Sunday when he went away to college,” she recalled. “He never has failed to keep that promise. When his right arm was useless from wounds, he learned to write with his left hand so that I’d continue to get my letters.”

The Canadian Government recently granted Doctor Banting an annuity of $7500 for life in recognition of his discovery of insulin, and the Ontario Legislature has appropriated $10,000 a year to create a department of research in the University of Toronto. This will be known as the Banting-Best Chair of Research. and Doctor Banting has been appointed its first incumbent at a salary of $6000 a year.

Today the eyes of the scientific world are turned toward Canada, eager to glimpse the new activities of the young physician who has become a world figure at an age at which most professional men are struggling for a foothold.

Some text has been edited to match contemporary standards and style.