Lactose Intolerance (Lactase Deficiency)
People who are lactose intolerant are unable to digest milk and milk products because they have insufficient amounts of lactase, the enzyme needed for digesting lactose, or milk sugar. Instead of being broken down and converted into glucose, or blood sugar, the lactose remains intact in the intestines, absorbing large amounts of water. This accumulation of fluid stimulates peristalsis, the rhythmic intestinal contractions that move material through the intestines, and results in gas, cramps, and diarrhea. In addition, certain bacteria that inhabit the colon ferment the lactose, leading to an even greater buildup of gas, and the passage of watery, acidic stools.
Typically, the discomfort and diarrhea hit within an hour after consuming milk products and disappear within a day after eliminating them from the diet.
The degree of lactose intolerance varies among individuals. Some have problems only when they consume large quantities of milk, while even small amounts trigger symptoms in others. Many people are unaware that they are lactase deficient until they abruptly increase their milk consumption. This often happens when older women start drinking more milk to obtain more calcium.
About two-thirds of the world's population suffer some degree of lactose intolerance. Lactase production gradually declines after infancy, when the diet no longer depends solely on milk. This natural occurrence is especially common among Native Americans and people of African, Mediterranean, Asian, and Middle Eastern descent. These persons can usually tolerate small amounts of lactose as children, but they have increasing difficulty in doing so as they grow older.
A small number of infants are born with congenital lactase deficiency. Some adults have other types of intestinal disease that hinder lactase production, making them lactose intolerant.
Diagnostic Studies and Procedures
Many people are never diagnosed with lactose intolerance because they normally avoid milk products. For anyone who is suffering symptoms, a doctor can usually pinpoint the condition by instructing the patient to abstain from milk products for a few days to see if symptoms disappear.
If this procedure is inconclusive, he may order a lactose intolerance test. This involves having the patient ingest an oral dose of 50 grams of lactose and then taking blood samples to measure glucose levels at specific intervals for the next two hours. The development of abdominal bloating and discomfort within a half hour and a below-normal rise in blood glucose indicate lactase deficiency. Another diagnostic test measures the amount of hydrogen exhaled before and after ingesting lactose.
Congenital lactase deficiency in an infant may require a biopsy of the small intestine to pinpoint the cause.
Medical Treatments
Medical care is usually not needed except for babies, who must be given a lactose-free formula. A doctor will also prescribe calcium supplements for a lactose-intolerant child, to ensure proper growth and development.
Alternative Therapies
Nutrition therapy is the mainstay of treatment. A nutritionist can help plan a diet that provides adequate amounts of calcium while avoiding milk. Foods other than milk contain small amounts of calcium; good sources are dark green vegetables, sardines with bones, torn (soybean curd), and legumes. But supplements will probably be needed if all milk and milk products are eliminated.
Self-Treatment
Most people who are lactose intolerant can consume small amounts of milk and milk products without developing symptoms, tb find your level of tolerance, first eliminate all milk products from your diet. (Check labels carefully for whey and other hidden sources of milk or milk sugar.)
Then try 1/2 to 1 cup of milk with a meal to see if it produces symptoms. Some people handle chocolate milk better than plain milk.
Those with lesser degrees of lactose intolerance can consume products whose lactose levels have been reduced by bacterial cultures that partly pre-digest it. Aged cheeses, buttermilk, sour cream, yogurt made with live cultures, and acidophilus milk have reduced lactose levels and are usually tolerated better than untreated milk.
People who are highly sensitive to lactose but still want to drink milk, can try taking it with lactase, available in tablets or liquid form. If this does not work (the enzyme may become neutralized in the stomach), a more satisfactory alternative might be lactose-free soy milk or milk with reduced lactose and added lactase. These products are usually available in large supermarkets and health food stores.
Other Causes of Intestinal Symptoms
Other food intolerances or malabsorption problems can produce bloating, gas, and diarrhea similar to those of lactose intolerance. Irritable bowel syndrome is also a possibility.