Insulin and Glucose

The hormone Insulin is a protein produced by the beta cells within the islets of the pancreas. Insulin is the primary regulator of glucose metabolism, which is the conversion of glucose into energy within the body, as well as the storage of excess glucose that the body doesn’t readily need.

Glucose enters the bloodstream principally through the consumption of carbohydrates(sugars and starches). When glucose levels are elevated (meaning when blood sugar is raised), a healthily functioning pancreas secretes insulin to metabolize the glucose, and the glucose is absorbed from the bloodstream into liver cells, muscle cells and fat cells for ready use as energy. Insulin also slows the natural production of glucose by the liver, and aids in the storage of excess glucose. This stored glucose becomes glycogen in muscle and liver tissues, and is ready to be turned back into glucose when blood sugar levels get low. In healthy individuals, these metabolic functions enabled by insulin keep blood sugar levels in a balanced range. This regulation is known as glucose homeostasis.

This integral balance between insulin secretion by the pancreas and glucose levels in the blood can be thrown off in several ways. Insulin resistance, for example, occurs when fat, liver and muscle cells do not absorb glucose from the blood due to a decreased ability to respond to the presence of insulin (lower “insulin sensitivity”). If this circumstance of glucose not being absorbed efficiently into cells persists, the pancreas becomes unable to produce enough insulin to maintain glucose homeostasis, resulting in prediabetes and eventually type 2 diabetes if changes in eating habits and lifestyle are not made. Often insulin resistance is brought on by excessive consumption of refined carbohydrates and processed foods with added sugars, which flood the body with glucose so quickly that the cells become overwhelmed. This process is also closely correlated to obesity, where the excess energy is converted into fat through a process called “lipogenesis.”

In type 1 diabetes, on the other hand, it is much more common for the beta cells within the pancreas to become damaged or destroyed, and for the pancreas to stop producing sufficient insulin levels for glucose absorption in the body. This leads to consistently high blood glucose levels and general deterioration of the body.

Type 1 diabetes and certain advanced stages of type 2 diabetes are treated by the administration of biosynthetic human insulin, either through injections or an insulin pump. Until the 1980’s, insulin administered to treat diabetes was actually synthesized from animals, such as dogs and pigs, with uncomfortable side effects, and before that there was no effective treatment known for diabetes.

Now human insulin is a rapidly growing multi-billion dollar medical treatment, one of the pharmaceutical industries’ greatest treasures. For most who need insulin, it must be taken every day, and with every meal, until death. So with the rising incidence around the world of diabetes and its partner-in-crime obesity, and continued trends towards diets based on refined and processed foods and lifestyles that are urban and sedentary, human insulin might end up challenging water, milk and coca cola as the world’s most consumed liquid. This is slightly facetious, of course, but it’s no joke that a whole range of factors are pushing diabetes into the mainstream; an almost accepted inevitability of the modern world, all while in truth type 2 diabetes is almost entirely preventable.

References and Further Reading

More about Insulin: 
https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance

A study about the business of Insulin production: 
http://clinical.diabetesjournals.org/content/21/1/40