How Carbs Affect Insulin?
Carbs are Converted to Glucose
Human body runs on glucose and all eaten carbs are converted into glucose in the digestive tract. The glucose then enters the bloodstream and thus contributes to a rise in “blood-glucose”.
Blood Glucose Must be Kept Within Limits
A very high level of glucose in the blood is toxic, while a very low level is detrimental to bodily functions. Therefore the body has a system to regulate the amount of glucose in the bloodstream to ensure that it remains balanced within safe parameters. This glucose balancing system depends upon two mechanisms: hunger and insulin.
Low Blood Glucose Triggers Hunger
If blood-sugar levels drop, the brain causes us to feel hungry. Result? We eat food that is then converted into glucose and our blood glucose levels rise. If we don’t eat and blood-glucose levels fall too low, we trigger the condition known as hypoglycemia.
High Blood Glucose Triggers Insulin
If blood-sugar levels rise, the brain tells our pancreas to release insulin. Result? The insulin disperses the glucose and our blood sugar levels fall. Without insulin to regulate a rise in blood-glucose, the amount of sugar in our bloodstream can become toxic, triggering the condition known as hyperglycemia.
Eating Too Many High GI Carbs Causes Sugar Spike
The hunger-or-insulin see-saw mechanism works well, if we don’t eat too many high glycemic index (GI) carbs that are rapidly converted into glucose. When this happens, when a LARGE amount of glucose enters the bloodstream (called a “sugar spike”), the system responds by releasing a LARGE quantity of insulin. (It thinks we’ve eaten a huge amount of food.) The amount of insulin is so large that not only does it disperse the food-glucose we have just eaten, it disperses a lot more. Result? Our blood glucose falls too low. So, within a short time (about 2-3 hours) the brain tells us to feel hungry and we repeat eating. This rapid rise and fall in blood glucose, caused by excess production of insulin, is not good for our health or our eating habits.
Insulin Levels and Health
As we have seen, when blood glucose levels get too high, insulin is released into the bloodstream by the pancreas to help disperse the glucose. The insulin transports the glucose to cells needing extra energy. The cells have “insulin receptors” positioned so that insulin can bind to them, facilitating glucose entry and utilization in the cells. Once inside the cells, the glucose is burned to produce heat and adenosine triphosyphate, (ATP) a molecule that stores and releases energy as required by the cell.
Overconsumption of High GI Carbs Maintains Excessively High Insulin
If we eat a diet that contains too many high GI carbs (carbs that are rapidly converted into blood glucose) we force our body to respond by releasing equally large amounts of insulin into our bloodstream to cope with the glucose. Over time this excessively high level of insulin can cause the “insulin-receptors” in our cells to become less sensitive to insulin.
When cells become less sensitive to the effects of insulin, they accept less glucose, so more glucose than usual remains in the bloodstream. Result? The pancreas over-compensates by working harder and releasing even more insulin.
Health Consequences of Insulin Insensitivity
The combination of insulin-insensitivity and insulin over-production typically leads to one of two results:
Either, the pancreas gets worn out and insulin production slows down to abnormally low levels. Result? We develop type 2 diabetes. (About 30 percent of cases)
Or, the insulin-resistant patient doesn’t develop diabetes (because the pancreas continues to produce sufficient insulin) but, instead, contracts hyperinsulinism (abnormally high levels of insulin in the blood), which can cause chronic obesity as well as high blood pressure, high levels of triglycerides, low HDL (good) cholesterol, heart disease, and possibly some cancers.
Low GI Foods Cause Lower Insulin Levels
This is why experts are beginning to recognize the health advantages of following a low GI diet. Because lower GI foods are converted into glucose much more slowly, causing less insulin to be produced.
This is not the last word on this subject, by any means. Research into insulin insensitivity and the relationship between insulin levels and obesity is ongoing. However, the overconsumption of high-GI foods is a major cause of concern.