What Are The Causes Of Insulin Resistance

Insulin is an important hormone in our body that is responsible for controlling how much sugar remains in our blood after we eat something. Insulin is made by the pancreas exclusively and its most important job is to remove glucose (from carbohydrates in food as well as the sugar release by the liver) away from the blood and feeds it to the muscles and cells so they can use the sugar as energy, keeping our bodies functioning and moving.

When someone starts to experience resistance to insulin, they are no longer able to properly respond to the hormone.  To compensate, the pancreas produces more and more insulin until it can no longer keep up.  Eventually, even high levels of insulin are not enough to remove and use sugar from the blood properly, so the blood sugar spikes very easily and can remain high for a dangerous amount of time, causing pre-diabetes, and type 2 diabetes.  In addition, this leads to more weight gain (insulin causes the body to store fat), inflammation in the blood vessels, heart disease and stroke risk, and damage to the small blood vessels in the eyes, kidneys, and feet. 

Insulin resistance is a pervasive condition that is associated with type 2 diabetes, pre-diabetes, metabolic syndrome, and weight gain.  It is typically present for years or even decades prior to someone becoming officially diagnosed with type 2 diabetes, the type that used to be called “adult onset” diabetes because it usually occurs later in life and is more associated with lifestyle habits than genetics.

“Doctors have been trained to measure a person’s fasting blood sugar, or the glucose levels present in your blood. The important thing to note is that blood sugar is the last thing to increase…so for many people, a fasting glucose test detects diabetes too late. Long before your blood sugar rises, your insulin spikes. High insulin levels are the first sign that can precede type 2 diabetes by decades.” – Mike Hyman, MD

There is many causes and contributors to insulin resistance, and usually several factors are at work. Among the biggest reasons why someone develops insulin resistance are:

• a poor diet, rich in processed carbohydrates, that leads to increased insulin secretion
• being overweight or obese, particularly central adiposity (apple-shape weight gain)
• some genetic factors (meaning they have inherited the trait that leads to IR)
• a stressful lifestyle which stimulates cortisol release that raises blood sugar
• lack of optimal physical activity and/or sedentary lifestyle
• improper sleep and rest
• various illnesses, infections, and immune dysfunction (gut problems are a common problem)
• certain medications can also add to growing insulin problems

Insulin resistance is a major contributor to a condition referred to as “metabolic syndrome”. When someone is diagnosed with having metabolic syndrome, this usually means they are experiencing problems managing blood sugar levels, are likely overweight, and may have high blood pressure or cholesterol.

“About 85 percent of people who have type 2 diabetes also have metabolic syndrome. These individuals have a much higher risk for heart disease than the 15 percent of people who have type 2 diabetes without metabolic syndrome.” – Dr. Axe 

Often the biggest causes of metabolic syndrome, insulin resistance, and eventually type 2 diabetes is being overweight and eating a poor diet that is high in sugar and processed foods.

These foods increase inflammation throughout the body, which causes the body to react by creating chemicals (called cytokines) that block insulin from properly doing its job. An inflammatory diet consists of refined carbohydrates (pasta, bread, white potato products, and cereal for example) and foods high in processed ingredients and sugar (ice cream, candy, cookies, and soda for example).

In addition to weight problems, other sources of inflammation can also lead to insulin resistance.  Factors such as stress, poor sleep, hormone imbalance, environmental toxins and problems with the gut microbiome have all been linked to insulin resistance.

Clearly, insulin is an important regulator of proper blood sugar and metabolism.  When cells become resistant to insulin, it leads to additional weight gain, damage to blood vessels, and other problems associated with diabetes.  Preventing and reversing insulin resistance involves addressing a variety of factors to improve health and optimize metabolic function.