Insulin is a hormone that is secreted by the pancreas, an organ that is found below and slightly behind the stomach. Insulin is produced and secreted by groups of cells called beta cells, which are scattered throughout the pancreas in areas called islets of Langerhans. When the body requires it, insulin is secreted into the bloodstream. The secretion of insulin is usually triggered by the presnce of sugar or amino acids (the building blocks of protein) in the bloodstream. The insulin than acts to move the blood sugar and the amino acids from the bloodstream into cells to be used for energy and other metabolic processes.
Insulin is known as a hormone of abundance because it is secreted when there is an abundance of nutrition available to the body. When a person consumes a lot of carbohydrates, and to a lesser extent, protein, insulin is secreted and circulates in the bloodstream at higher levels. Insulin does many things in the body to help store energy and build up tissues when there is an abundance of carbohydrates and protein. Below are top seven things insulin does in the body:
- Insulin moves blood sugar from th bloodstream into the body's cells for use and storage.
- Insulin stimulates the production and storage of fat. It may contribute to a rise in triglycerides (blood fats) in the process.
- Insulin increases the production of cholesterol in the liver.
- Insulin helps to move amino acids, which are the building blocks of protein, into the body's cells.
- Insulin causes the kidneys to hold sodium. This effect may be responsible for the association between high insulin levels and high blood pressure.
- Insulin stimulates the production of hormones called eicosanoids. These are microhormones that regulate a number of functions in cells adn in circulatory system (clotting, inflammation, and constriction of blood vessels). These may also contribute to high blood pressure and heart diseases.
- Insulin also suppresses hunger. However, this is a controversial point, because in practice, when insulin is injected into individuals with diabetes, it appears to contribute to hunger and obesity.
When the body has to process an overabundance of blood sugar over a long period of time, two things can happen. You can have a chronically high levels of insulin in your blood simply because your body needs the insulin to process the blood sugar. Also, insulin resistance can set in. Insulin resistance describes a situation in which the body resists the action of insulin. It is often associated with obesity, a high-fat diet and lack of exercise, coupled with genetic predisposition.
INsulin is like a key to open the lock that lets blood sugar into the body's cells. When there is insulin resistance, the keys don't work properly and the body has difficulty getting the sugar out of the blood. This causes sugar levels in the blood to rise. When the body sense the blood sugar rise, it prodices more insulin. This cycle continues and the body is exposed to high levels of insulin because it is trying to secrete more insulin to make up for the ineffectiveness of insulin due to the "insulin resistance."
Whether you have high insulin levels because of a high exposure to blood sugar or because you have insulin resistance, it becomes a problem even if you don't have diabetes. High levels of insulin are implicated in a number of health problems, such as high blood pressure, high cholesterol, and possibly obesity. When these conditions are severe enough, it may be considered to be Syndrome X or Metabolic Syndrome, because the common link among these health problems may be high insulin levels.
Most people with type 2 diabetse have insulin resistance, but many people who are not diabetic also have insulin resistance. Since insulin resistance itself often does not cause symptoms, these people may not be aware of their problem but may often be overweight. Insulin resistance may worsen with increased use of saturated fat and improved with increased unsaturated omega-3 fatty acids from fish, while the role of other unsaturated fats is lss clear. High-carbohydrate diets have also been shown to improve insulin sensitivity; the reason for this may partly be that weight loss often occurs on this type of diet, or that these diets are low in fats, such as saturated fat, which worsens insulin sensitivity.