Posted on 24 September 2014
• Lactose is a sugar found in milk and milk products.
• Lactose intolerance is a condition in which people have digestive symptoms—such as bloating, diarrhea, and gas—after eating or drinking milk or milk products.
• A health care provider makes a diagnosis of lactose intolerance based on medical, family, and diet history, including a review of symptoms; a physical exam; and medical tests.
• Basing a diagnosis on symptoms alone may be misleading because digestive symptoms can occur for many reasons other than lactose intolerance.
• Most people with lactose intolerance can tolerate some amount of lactose in their diet and do not need to avoid milk or milk products completely. However, individuals vary in the amount of lactose they can tolerate.
• Research suggests that adults and adolescents with lactose malabsorption could eat or drink at least 12 grams of lactose in one sitting without symptoms or with only minor symptoms. This amount is the amount of lactose in 1 cup of milk.
• Many people can manage the symptoms of lactose intolerance by changing their diet. Some people may only need to limit the amount of lactose they eat or drink. Others may need to avoid lactose altogether.
• People may find it helpful to talk with a health care provider or a registered dietitian to determine if their diet provides adequate nutrients— including calcium and vitamin D. To help ensure coordinated and safe care, people should discuss their use of complementary and alternative medical practices, including their use of dietary supplements, with their health care provider.
• Lactose is in all milk and milk products. Manufacturers also often add milk and milk products to boxed, canned, frozen, packaged, and prepared foods. People can check the ingredients on food labels to find possible sources of lactose in food products.