Sugar’s Slippery Slope: Insulin Sensitivity and Type 2 Diabetes

Jonathan Vellinga, MD -

Sugar’s Slippery Slope: Insulin Sensitivity and Type 2 Diabetes

Alarmingly, the body can be unintentionally trained into a diabetic state. As more and more sugars are taken into the diet, certain mechanisms are triggered that become stronger and more ingrained until type 2 diabetes can be diagnosed. The good thing is what can be trained into the body can also be undone, though it may take some effort.


Diabetes and pre-diabetes caused by blood sugar dysregulation continue to climb in the United States, with about 40% of the population affected, roughly 130+ million people (1, 2). This is why we at Temecula Center for Integrative Medicine continually emphasize education, prevention, and functional medicine treatments for many blood sugar-related conditions, including diabetes, pre-diabetes, and insulin resistance. Please see our article entitled “Insulin Resistance, Diabetes, and Functional Medicine” for a good grounding in those health conditions.


The purpose of this article is not to repeat the excellent information of our previous article. Rather, the aim is to focus on some of the mechanisms that make diabetes possible and how to use that knowledge to decrease the risk of dysregulated blood sugar conditions in the first place.


Decreased insulin sensitivity → insulin resistance → prediabetes → Type 2Diabetes


Carbohydrates such as sugars in the diet are converted by the liver into glucose and released into the bloodstream. The glucose concentration in the blood is also known as “blood sugar.“ The cells in tissues of the human body need some glucose, which they use as fuel, but it’s rather dangerous to the body to have too much or too little. There are many mechanisms in place that the body uses to regulate the amount of glucose in the bloodstream.


Insulin is a hormone created by the pancreas. One of insulin’s “jobs” is to help get glucose across a cell membrane and into a cell. Glucose cannot enter a cell at all without the presence of insulin. A mental picture that can be used is that of insulin “knocking” at the door of the cell, and when the cell “sees” the insulin and glucose there, it allows the glucose across the cell membrane and into the interior of the cell. The cell can then degrade the insulin, or allow the insulin to make its way to the liver or kidneys. The glucose is then either utilized or stored.


Insulin sensitivity” is a term that describes how efficiently the cells in a body respond to insulin. Having a high sensitivity would mean that the cells are very responsive to the insulin, and easily allow the insulin to tuck the glucose into the cell, across the cell membrane. Low sensitivity to insulin is considered an impairment, where the cell is not very responsive to the presence or the action of the insulin, leaving the rejected glucose to linger in the bloodstream. This mechanism can get stuck in an impaired, low-sensitivity state that can cascade into a feedback loop that ends in the diabetic state.


The next step into the damaging feedback loop is “insulin resistance.” It is also known as “impaired insulin sensitivity” (3). This is an abnormal state of consistently weak insulin sensitivity that can be diagnosed by the amount of circulating glucose in the blood, the hemoglobin A1C blood test, and symptoms. (Some labs will also measure circulating insulin and several other factors in the serum to come up with an “insulin resistance” (IR) score.)


It is thought that chronically low insulin sensitivity contributes to insulin resistance, and certainly, insulin resistance is characterized by low insulin sensitivity. However, note that many factors can contribute to insulin resistance besides low insulin sensitivity, including diet, exercise, and genetics.


When insulin resistance is high, glucose stays in the bloodstream longer, and the body’s response is to make more insulin because the beta cells in the pancreas sense there is still glucose in the bloodstream that needs to be tucked into cells. The state of chronically high insulin is called hyperinsulinemia. If the pancreas’s release of insulin can stay on top of regulating the glucose levels, keeping the concentration of glucose in the blood in a narrow range, all is well.


However, if the system keeps getting overwhelmed with glucose (as from the diet), it can lead to hyperglycemia – the state of a consistently high amount of glucose in the bloodstream. Insulin and glucose are now bombarding the cells. Imagine that many cells, being overwhelmed, hear the insulin knocking at the door, but won’t open the door to let the glucose in, as they’ve already had enough glucose. At this point, eating more carbohydrates (sugars) simply compounds the hyperglycemic state. Chronic states of hyperglycemia and hyperinsulinemia both increase the risk of pre-diabetes and, eventually, diabetes.