Lactose intolerance is a condition in which there is insufficient quantities of the enzyme lactase present for the proper digestion of dairy products. Lactose intolerance is common and progressive. It is one of the most common gastrointestinal disorders encountered by primary care physicians in practice with approximately twenty percent of Caucasians and between fifty and eighty percent of Hispanics, African Americans, Native Americans, and Asians develop lactose intolerance as they age. The lowest incidence of lactose intolerance is in North American whites and northern Europeans., 
|Causes||Food Reactions, Genetics, Stress|
|See Also||Infections / Allergies / Sensitivities, Digestive Conditions, Celiac Disease, Crohn's Disease|
|Books||Books on Infections, Allergies, Intolerances|
|Articles||Articles on Infections / Allergies / Sensitivities|
- Lactase is the enzyme that digests the sugar lactose which is a combination of glucose and galactose and is the form of sugar found in milk. Though typically plentiful in infants, the quantity of this enzyme that is produced by the body declines naturally with age.
- Lactose is often added to food products as a way of changing their texture, flavor, aroma, and color. It is also added to a variety of non-food products such as over the counter medications.
- Lactose intolerance can occur temporarily as a result of infection.
- Lactose intolerance can lead to severe gastrointestinal disorders if the individual with this affliction continues to consume food containing lactose.
- When a person with lactose intolerance consumes dairy products that contain lactose, they can develop symptoms ranging from mild dyspepsia, burping, bloating and flatulence to severe abdominal cramping and diarrhea.
- Lactose intolerance and irritable bowel syndrome (IBS) can cause very similar physical presentations. For this reason, lactose intolerance should be ruled out before IBS is diagnosed. Furthermore, IBS can be caused by lactose intolerance, and symptoms of IBS may improve if lactose is removed from the diet.
- Conditions that cause damage to the intestinal villi can lead to a decrease in the activity of the enzyme lactase. For this reason, lactose intolerance can result from:
- Some beneficial gut flora can breakdown lactose. Therefore, if the balance of gut flora is disturbed, as can occur form the use of antibiotics, this can contribute to lactose maldigestion.
Diagnosing lactose maldigestion can be effectively done by measuring breath levels of hydrogen and methane. It is commonly done by monitoring a person's reaction to the consumption of dairy and then removing the dairy and testing to see if the symptoms resolve.
- The treatment for lactose intolerance involves the removal of all lactose and lactose based products from the diet.
- For many with lactose intolerance it is best to avoid all forms of dairy as bacterial cultures in yoghurt, cheese, and buttermilk typically contain some lactose, also it is common for those with lactose intolerance to have other food intolerances which could include reactions to other proteins in dairy.
- At times, especially when the lactose intolerance developed later in life, treating other associated conditions can result in the ability to tolerate lactose again.
- Spallholz Julian E (1999) Nutrition, Chemistry and Biology, Second Edition, CRC Press.
- Pizzorno JE, Murray MT (2006) A Textbook of Natural Medicine, 2nd Edition, Churchill Livingston Elsevier.
- Hoffer Abram, Prousky Jonathan (2006) Naturopathic Nutrition, a Guide to Health Food and Nutritional Supplements CCNM Press.