Glucose is by far the most common type of carbohydrate present in nature. More complex carbohydrates such as starch are made out of hundreds or thousands of glucose units chained together. The digestive system breaks these complex carbohydrates and then absorbs the individual glucose units into the blood to provide the cells with energy. This is the provenance of the term blood sugar. Any type of food that contains carbohydrates, including dairy, will raise your blood sugar.
Glycemic Index
The glycemic index, or GI, is a measure of the impact that carbohydrates have on blood sugar. By measuring the effect of carbohydrates directly, it can take into account all of the factors that influence blood sugar, including the specific method of food preparation and processing, the quantity of carbohydrates in the food and the complexity of the carbohydrate molecule. For example, simpler carbohydrates tend to raise blood sugar faster than complex carbohydrates.
Lactose
Milk raises blood sugar because it contains the sugar lactose, which forms from the union of galactose and glucose. With only a small concentration of lactose, milk has a less pronounced effect on blood sugar than spaghetti, rice, fruits and bread. Lactose makes up only 4 to 6 percent of cow's milk. In absolute terms, milk contains 13 g of carbohydrates. Other dairy products may vary in their quantity of carbohydrates.
Glycemic Index of Dairy
An 8 oz. serving of skim milk has a glycemic index of 32 relative to glucose, meaning that it provokes a blood sugar response that is only 32 percent as large as the effect of pure glucose. Anything under 55 is low. Other dairy products also tend to have a low effect on blood sugar, although it depends largely upon whether the manufacturers alter the carbohydrate content. A typical cup of reduced fat yogurt with fruit has a glycemic index of 27; check the label to see whether the yogurt has any additional sugar, which will increase its GI. If you want to eat ice cream, then you should buy premium ice cream, with a GI of 37, instead of regular, with a GI of 61. Cheese is low in carbohydrates and should have a negligible GI number.
Diabetes
Chronically elevated levels of blood sugar can cause the cells to become resistant to insulin, a hormone that removes glucose from the blood. This condition is commonly known as type 2 diabetes. If you have diabetes, then a doctor will usually prescribe a special diet to control blood sugar. The American Diabetes Association recommends low fat or fat free milk and yogurt as a rich source of calcium and high quality protein on a diabetic diet. If you are lactose intolerant, then you may want to try fortified soy milk instead.
