The sugar lactose is a disaccharide that is found in dairy products. It is called a disaccharide because it is made of two monosaccharides, or two simple sugars. People who are lactose intolerant cannot easily digest the lactose in dairy products, yet some people have a mild intolerance for they may be able to drink up to 12 oz. of milk every day.
Lactase Enzyme
Carbohydrates include starches and sugars such as sucrose, glucose and lactose. All carbs are absorbed in the small intestines. For lactose to be absorbed, the small intestines must use an enzyme called lactase. Enzymes are proteins used by the cells of the body to speed up the time of a biochemical reaction. There are two kinds of lactase deficiency: primary and secondary.
Lactase Deficiency
People with a lactase deficiency do not have enough of the lactase enzyme or do not have any of the enzyme at all. In either case, they are lactose intolerant because they cannot break down the lactose sugar that is found in dairy products. Those with primary lactase deficiency have a genetic lack of the lactase enzyme. People with secondary lactase deficiency have an abnormality in the small intestines that affects the lactase enzyme.
Symptoms of Lactose Intolerance
Lactose accumulates in the small intestines of those who are lactose-intolerant. This accumulation draws minerals and water, which results in a watery diarrhea. In addition, the bacteria in the large intestines ferment lactose. This is why people with lactose intolerance not only have a watery diarrhea, but also are often bloated with gas and abdominal pain.
Treatment
Anyone with a lactose intolerance who still wants to eat and drink dairy products can take lactase enzyme supplements. They can buy these supplements over the counter and do not need a prescription. The brand names include Lactrase, Lactaid and Lac-Dose. The medication is not broken down by the acid in the stomach, but it can break down the lactose sugar before it is absorbed in the small intestines.
References
- "Gastrointestinal Physiology"; Kim Barrett; 2006
- "Harrison's Principles of Internal Medicine"; Dr. Anthony Fauci et al.; 2008
- "Merck Manual for Healthcare Professionals": Carbohydrate Intolerance
