Saturday, August 9, 2014

The Nutrition Debate #234: You begin to secrete insulin when…

Whether you’re a type 2 diabetic or not, your body’s mechanism for regulating the level of glucose circulating in your blood begins the same way. It is a complex process, and far beyond my pay grade to explain in detail, but I can give you an overview of how it works and affects your health. If you’re interested enough, you can follow the links to learn more.
Everyone has a brain and a functioning autonomic nervous system, and, as long as we’re alive, they work basically the same way. We breathe, our hearts beat, our temperature is regulated, and we are driven by elemental forces within us to eat, procreate and sleep. For survival, optimum health, and “longevity,” the body “tells” us what to do and when to do it. One of those elemental drives is eating. The body needs food to grow and sustain itself. So, we seek food.
We have learned through the ages what to eat. Through an evolutionary process, by adaptation, we became omnivores. Eating both animal and vegetable foods allowed the human species to spread far and wide. Populations adapted to the variety of foods available in different climates and seasons and in times of both feast and famine. To kill, catch or gather food, we used our senses and motor skills and our developing intellectual powers. But, first and foremost, before all the rest, when our bodies told us we were hungry, our senses kicked in. Our senses provided the message to seek and find food.
First among our senses was sight. By some estimates, ninety percent (90%) of what we perceive is visual. The sight of food excites our brain and sends a signal to the pancreas to secrete insulin in preparation to transport glucose (energy converted from food) throughout our circulatory system. That energy replaces glycogen that has been stored in muscle and the liver and has been depleted by use, both to maintain our basal metabolism and for motor activities like hunting, fishing or gathering, and for preparing food and eating it. As much as 10% of food energy is used just in digesting and absorbing it.
The smell of food excites our brain and sends a signal to the pancreas to secrete insulin. Everybody knows that. (Does this sound like a Geico commercial?) And personally, I think the smell of food is a more powerful stimulant to eat (and therefore possibly a more powerful stimulant to secrete insulin) than the sight of food. The smell of food being cooked is closer in time to eating it, and more of a certainty than just seeing food “on the hoof with the prospect of a kill. Thus, it is a more physiologically appropriate time to have an elevated level of insulin circulating in the blood.
Even thinking about food, which many dieters say they do all the time, excites our brain and sends a signal to the pancreas to secrete insulin. I imagine, as I think about and write two columns a week for The Nutrition Debate, my serum insulin must always be somewhat elevated. And since insulin is the hormone that type 2 diabetics have issues with, having a constantly elevated serum insulin, can be problematic. Do you know what your fasting insulin level is? Mine has only been tested once, in 2013. It was 7.8mU/L (range 3.0-25.0).
Then, of course, the taste of food, associated with the response of the digestive enzyme amylase mixed with mucus from the three pair of salivary glands in the buccal cavity (mouth), excites the brain and sends a signal to the pancreas to secrete insulin. In the “normal” metabolism, this is a burst of insulin that prepares your digestive system to ramp up to secrete a bunch more to handle the food passing into the alimentary canal and on to the small intestine where the final digestion and absorption processes occur. Mysteriously, most type 2s havelost the ability to generate this anticipatory burst of insulin.
All of these sensory processes are normal. In fact, they are, as we said at the beginning, elemental survival traits. And they are autonomic, meaning they happen automatically without conscious initiation. However, we do have total awareness of them, and we act on them. We seek food and water to feed our bodies to sustain ourselves. It is fundamental survivalism.
But what happens when some part of these metabolic mechanisms breaks? When the supply of insulin is lessened because our pancreatic beta cells (in the Islets of Langerhans which secrete insulin) die? Or when the insulin we have been able to produce circulates with the glucose from digested food but is not taken up by the body’s cells to replace the glycogen that’s been used up by ordinary living? Answer: With a “broken” metabolism, your blood sugar rises, you get type 2 diabetes, and your risk factors for microvascular and macrovascular diseasesincrease dramatically.
What happens when we can no longer produce enough insulin to transport and allow the “uptake” of blood glucose? Until synthetic insulin was developed in 1922, you died from hyperglycemia. The only “therapy” for those unfortunate souls was to eat a strict ketogenic diet, in which virtually no carbohydrates were consumed. Today, if you allow your type 2 diabetes to progress to the point where you have “uncontrolled” blood sugar, you can inject insulin to regulate your blood sugar.
But if you are pre-diabetic (or a diagnosed type 2), and you don’t want your diabetes to progress to that point, is there an alternative for you to injecting insulin? Is there something else you can do to preserve what function your pancreas has left to make insulin? Answer: You can adapt what you eat for survival. You can eat fewer carbs. Your life may depend on it.


  1. And you need to be sure to control you blood glucose. I just read an interesting study that says that glucose toxicity is a continuous function that starts at 100 mg/dl. It results in beta cell death. This is much lower than other diabetic complications seem to start at.

    1. Good stuff. Thanks for the link. Readers: look for column on this after Labor Day.