If you haven’t read Carbology 101 please read that first for the carbohydrate basics. In 102 we are going to discuss the uptake of carbohydrates from the blood to tissues and cells.
Insulin is known by many as the hormone associated with diabetes. There are two types of diabetes. Type I is where the pancreas loses the ability to make insulin, where as type II diabetes the pancreas may still create some insulin or the person may be so insulin resistant that the pancreas can not make enough to control their blood sugar. Elevated blood sugar (hyperglycemia) occurs when the body is not able to increase glucose uptake into the cells in relation to what has been ingested and released into the blood stream.
The problem with diets that are high in sugary carbohydrates is that the body is always having to dispose of that sugar. This puts a tremendous strain on the pancreas which can be one cause of diabetes. On top of that, cells that are constantly being exposed to insulin, and often become insulin resistant over time. This means it will now take more insulin to get the cell to uptake glucose from the blood making even more work for the already stressed pancreas.
Aside from increasing body fat, having constant high levels of blood sugar increases inflammation and also leads to the creation of AGEs (Advanced Glycation End-products). These AGEs form when proteins in your blood get bound to the sugars, creating an almost syrup type material in your arteries. This is not good for your health in many ways and is extremely aging to the body. The more AGEs you make, the more likely you won’t live to see a very old age. So you might want to start thinking twice about eating high sugar foods, regardless of your weight, or insulin sensitivity.
How Does Insulin Work?
When your blood sugar starts to raise, your pancreas responds by secreting insulin into the blood. Insulin then signals certain cells through an insulin receptor to start moving special proteins into the cell membrane. These proteins are referred to as glucose transporters or GLUT proteins. Some cells in your body do not regulate their glucose uptake and just allow it in freely. These cells are like liver, kidney, brain, and red blood cells. No coincidence that diabetes patients have issues with all those organs. The rest of the cells require the GLUT transporters to get glucose into the cell. In a healthy person, insulin will stimulate GLUT in muscle and fat, but about 70-80% of the glucose will be take up by the muscle tissue because it has more insulin receptors. In a person who has abused carbohydrates, their body will start to create more insulin receptors on the fat cells, making more of the carbohydrate you eat, get stored as fat. For a in depth look, here is a medical break down from Cornell University.
The increase in insulin sensitivity of fat and decrease of it in muscle tissue is why being fat and insulin resistant is a double edged sword. The more fat you have and the more insulin receptors the fat cells have, the harder it gets to lose fat and the easier it gets to store fat. Often times when people lose control of their weight and suddenly gain massive amounts of fat in a short period of time, they have reached a tipping point where they are now storing significantly more glucose as fat without making any major changes in their diet.
Exercise can also stimulate GLUT-4 production in muscle cells that are being worked via a different mechanism independent of insulin. This is why post workout carbohydrates are ok for some people. If however you are a person who has abused carbohydrates and has many insulin receptors on your fat cells, post workout carbs can still be taken up into fat tissue. Charles Poliquin likes to preach that you have to deserve your carbs. This is exactly what he means. These people need to avoid carbs all together until they start to rebalance their insulin sensitivity.
For an overweight person who is insulin resistant, exercise is their best friend. The more physical activity, especially resistance training, the more they can influence glucose being stored as lean muscle mass rather than fat. For diabetics this also takes a significant load of the pancreas, and combined with a low carb diet can start to rehabilitate their pancreas. Increasing muscle mass through resistance training gives your body a better chance at rebalancing insulin sensitivity. Proper weight training can also increase the amount of insulin receptors and the GLUT response in the existing muscle cells pushing the balance even further in your favor.
If you don’t work on correcting insulin sensitivity with exercise and supplementation, diet alone will not always work well enough. Not being able to have any carbohydrates in your diet is not very healthy (discussed in future articles). Switching to just a low carb diet will help, but your body also makes carbohydrates from non carbohydrates sources. Every morning your body releases cortisol to signal your body to start making energy. Part of this process is to start making carbohydrates from protein and releasing stored carbohydrates from your liver and muscle tissue. This is how even without eating carbs you can be feeding fat cells with glucose right out of your own body. So you can see it’s just as important to restore your bodies ability to handle carbohydrates and insulin properly as it is to monitor them in your diet. That is where we will start 103, more about insulin and our health and the insulin cortisol seesaw.