Lactose intolerance is the inability to digest lactose (a type of sugar found in milk and other dairy products).
Alternative NamesLactase deficiency; Milk intolerance; Disaccharidase deficiency; Dairy product intolerance
Causes, incidence, and risk factorsLactose intolerance happens when the small intestine does not make enough of the enzyme lactase. Babies' bodies make this enzyme so they can digest milk, including breast milk. Before humans became dairy farmers, most people did not continue to drink milk, so their bodies did not make lactase after early childhood.
Lactose intolerance is more common in Asian, African, African-American, Native American, and Mediterranean populations than it is among northern and western Europeans.
Lactose intolerance can begin at different times in life. In Caucasians, it usually starts to affect children older than age 5. In African-Americans, lactose intolerance often occurs as early as age 2.
Lactose intolerance is very common in adults and is not dangerous. Approximately 30 million American adults have some amount of lactose intolerance by age 20.
Lactose intolerance is sometimes seen in premature babies. Children who were born at full term generally do not show signs of lactose intolerance until they are at least 3 years old.
Not having enough lactase (lactase deficiency) may also occur as a result of intestinal diseases such as celiac sprue and gastroenteritis, or after bowel surgery. Temporary lactase deficiency can result from viral and bacterial infections, especially in children, when the cells lining the intestine are injured.
SymptomsSymptoms often occur after you eat or drink milk products, and are often relieved by not eating or drinking milk products. Large doses of milk products may cause worse symptoms.
Signs and testsRemoving milk products from the diet usually improves the symptoms. However, not having milk in the diet can lead to a shortage of calcium, vitamin D, riboflavin, and protein. Add other sources of calcium to the diet if you remove milk products.
Most people with low lactase levels can tolerate 2 - 4 ounces of milk at one time (up to one-half cup). Larger (8 oz.) servings may cause problems for people with some amount of milk intolerance.
These milk products may be easier to digest:
You can add lactase enzymes to regular milk or take them in capsule or chewable tablet form.
You may need to find new ways to get calcium into your diet (you need 1,200 - 1,500 mg of calcium each day):
Read food labels. Lactose is also found in some non-milk products -- including some beers.
Expectations (prognosis)Symptoms usually go away when milk products are removed from the diet.
ComplicationsWeight loss and malnutrition are possible complications.
Calling your health care providerCall your health care provider if:
There is no known way to prevent lactose intolerance.
If you have the condition, avoiding or restricting the amount of milk products in your diet can reduce or prevent symptoms.
ReferencesInformation from your family doctor. Lactose intolerance: what you should know. Am Fam Physician. 2006;74:1927-1928.
Hogenauer C, Hammer HF. Maldigestion and Malabsorption. In: Feldman M, Friedman LS, Sleisenger MH, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2006: chap98.
Lactose intolerance is the inability to digest lactose. Lactose is a type of sugar found in milk and other dairy products.
Alternative NamesLactase deficiency; Milk intolerance; Disaccharidase deficiency; Dairy product intolerance
Causes, incidence, and risk factorsLactose intolerance happens when the small intestine does not make enough of the enzyme lactase. Enzymes help the body absorb foods. Not having enough lactase is called lactase deficiency.
Babies' bodies make this enzyme so they can digest milk, including breast milk.
Premature babies sometimes have lactose intolerance. Children who were born at full term usually do not show signs of lactose intolerance until they are at least 3 years old.
Lactose intolerance can begin at different times in life. In Caucasians, it usually affects children older than age 5. In African Americans, lactose intolerance often occurs as early as age 2.
Lactose intolerance is more common in people with Asian, African, Native American, or Mediterranean ancestry than it is among northern and western Europeans.
Lactose intolerance is very common in adults and is not dangerous. Approximately 30 million American adults have some amount of lactose intolerance by age 20.
Causes of lactose intolerance include:
Symptoms often occur 30 minutes to 2 hours after you eat or drink milk products, and are often relieved by not eating or drinking milk products. Large doses of milk products may cause worse symptoms.
Symptoms include:
Infants or children may have slow growth or weight loss.
Signs and testsOther intestinal problems, such as irritable bowel syndrome, may cause the same symptoms as lactose intolerance.
Tests to help diagnose lactose intolerance include:
Decreasing or removing milk products from the diet usually improves the symptoms.
Most people with low lactase levels can drink 2 - 4 ounces of milk at one time (up to one-half cup) without having symptoms. Larger (more than 8 oz.) servings may cause problems for people with lactase deficiency.
These milk products may be easier to digest:
You can add lactase enzymes to regular milk or take these enzymes in capsule or chewable tablet form.
Not having milk in the diet can lead to a shortage of calcium, vitamin D, riboflavin, and protein.
You may need to find new ways to get calcium into your diet (you need 1,200 - 1,500 mg of calcium each day):
Read food labels. Lactose is also found in some non-milk products -- including some beers.
Expectations (prognosis)Symptoms usually go away when you remove milk products or other lactose containing products from the diet.
ComplicationsWeight loss and malnutrition are possible complications.
Calling your health care providerCall your health care provider if:
There is no known way to prevent lactose intolerance.
If you have the condition, avoiding or restricting the amount of milk products in your diet can reduce or prevent symptoms.
ReferencesGenauer CH, Hammer HF. Maldigestion and malabsorption. In: Feldman M, Friedman LS, Sleisenger MH, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010: chap 101.
Lactose intolerance. The National Digestive Diseases Information Clearinghouse (NDDIC). NIH Publication No. 09-2751. June 2009.
Reviewed ByReview Date: 07/07/2010
David C. Dugdale, III, MD. Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Lactose Intolerance occurs in the digestive system.
A gastroenterologist treats lactose intolerance and ulcers.
Galactose is involved with lactose intolerance, but is not responsible for lactose intolerance. The enzyme that is missing or is not found in great enough quantities in the body, lactase, is responsible for not breaking down lactose. This is how the intolerance comes about. The body cannot properly break down lactose without the enzyme lactase present.
Lactose intolerance occurs when the digestive system is no longer able to metabolise the sugars (lactose) found in dairy products through producing insufficient amounts of an enzyme called lactase.
No
The Basques. They are virtually free of lactose intolerance.
intestinal gas and bloating after dairy products are consumed
Lactose intolerance results from an inability in the small entrails to digest lactose. You can get so many carbohydrates or sugar in milk what's called lactose. You should avoid this.
women
Lactose Intolerance - 2011 was released on: USA: 27 September 2011 (DVD premiere)
The most common is lactose intolerance.
They are known as people with lactose intolerance - and that's about it.