By Annette R. Karnash, R.N., M.N.
Despite sharing the same chemical composition, all carbohydrates are not equal. Eating the right type of carbohydrate can help control weight while cutting heart disease, diabetes and minimizing the risk of hypoglycemia.
Bread, pasta and potatoes are all carbohydrates; however carbohydrates are a chemical composition of many different foods. The include simple sugars, such as glucose and fructose, complex sugars, such as sucrose and lactose or 2 simple sugars that are linked and starch complex molecules made up of thousands of linked glucose molecules. For example, bread contains carbohydrates, fats, proteins, vitamins, minerals and other nutrients. Milk is not thought of as a carbohydrate, but it contains lactose, and protein, fat, calcium and water.
Our digestive process converts carbohydrates into glucose, which is the fuel needed by all the cells in the body. As the glucose in the blood stream increases, the pancreas needs to produce additional insulin to convert the glucose into energy. Foods that have comparable carbohydrates can have varying effects on the blood sugar. Some carbs raise blood sugar levels sharply while others have little effect. To determine a particular foods effect on blood sugar levels, a glycemic index is used. At the top of this 100 point scale is glucose. Consumption of glucose causes the highest rise in blood sugar. Other foods are lower on the scale. The higher the foods glycemic index, the greater its effect on the blood sugar.
The chief determinant of glycemic index is the speed at which it is digested. Carbs that break down into glucose quickly raise blood sugar sharply. Slow digesting carbs keep blood sugar on an even keel. The size of the food particle determines the speed of digestion. The smaller the particle, the faster the food is digested and the higher the glycemic index.
Baking, cook and other forms of processing increase starch gelatinization which increases the glycemic index. Processed foods have high glycemic indices. Canned pasta, cooked for long periods have a higher glycemic index than pasta cooked al dente. The body functions best with a blood sugar at a constant level. Increasing the proportion of low glycemic index foods promotes weight loss, lowers the risk of diabetes, guards against heart disease and reduces the risk of hypoglycemia.
Low glycemic index foods stay in the digestive tract longer thereby providing a lasting feeling of satiety. Cells that repeatedly subject to surges of insulin become less sensitive to its effects. Eventually the pancreas can’t produce sufficient amounts of insulin to overcome the cells insulin resistance and diabetes can develop. Eating a low glycemic index diet helps prevent insulin resistance and allows autoimmune drugs to work efficiently, thus reducing the risk of complications, especially kidney disease. And if diabetes and obesity are prevented, heart disease can be prevented by raising the levels of HDL (the good guys), which carries fat away from the coronary arteries.
High glycemic foods need not be eliminated, but low glycemic index foods should compose the majority of the diet. Surprisingly, table salt and honey have a glycemic index equal to that of whole wheat bread because they break down into glucose as well as fructose which is converted into glucose very slowly. Examples of low glycemic index foods are oatmeal, sourdough, pumpernickel and stone ground whole wheat breads, pasta, boiled potatoes, lentils, chick peas, kidney beans and low fat yogurt.
