Insulin
Year of Discovery: 1921
What Is It? Insulin is a hormone produced by the pancreas that allows the
body to pull sugar from blood and burn it to produce energy.
Who Discovered It? Frederick Banting
Why Is This One of the 100 Greatest?
Frederick Banting discovered a way to remove and use the pancreatic “juice” of animals to save the lives of diabetic humans. This hormone is called insulin. Its discovery has
saved millions of human lives. Diabetes used to be a death sentence. There was no known
way to replace the function of a pancreas that had stopped producing insulin. Banting’s
discovery changed all that.
Although insulin is not a cure for diabetes, this discovery turned the death sentence of
diabetes into a manageable malady with which millions of people live healthy and normal
lives.
How Was It Discovered?
In early 1921, 28-year-old Canadian orthopedic surgeon Frederick Banting developed
a theory—actually, it was more of a vague idea—for a way to help people suffering from
diabetes.
The outer cells of the pancreas produced strong digestive juices. But the inner cells
produced a delicate hormone that flowed straight into the blood. Muscles got their energy
from sugars in the bloodstream, which came from food. But the body couldn’t pull sugar out
of the bloodstream without that hormone from the inner cells of the pancreas.
When the inner cells of a person’s pancreas stopped making that hormone, their muscles couldn’t draw sugar from the bloodstream, and the bloodstream became overloaded
with sugar and struggled to get rid of it through excess urination. The body dehydrated; and
the patient became deathly ill. This condition was called diabetes.
In 1920 there was no cure for diabetes. It was always fatal.
Researchers had tried obtaining the pancreatic hormone (which they referred to as
“juice”) from animals. But when a pancreas was ground up, the digestive juices from the
outer cells were so strong that they destroyed the delicate juice from the inner cells before it
could be used.
Banting read an article by Dr. Moses Barron that described the fate of several patients
in whom a blockage had developed in the ducts carrying pancreatic outer cell digestive
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