People with lactose intolerance are unable to fully digest the sugar in milk. As a result, they have diarrhea, gas and bloating after eating or drinking dairy products. The condition, which is also called lactose malabsorption, is usually harmless, but its symptoms can be uncomfortable.
A deficiency of this enzyme produced in your small intestine – is usually responsible for lactose intolerance. Many people have low levels of enzyme but are able to digest milk products without problems. If you're actually lactose intolerant, though, your lactase deficiency leads to symptoms after you eat dairy foods.
Most people with lactose intolerance can manage the condition without having to give up all dairy foods.
The signs and symptoms of lactose intolerance usually begin 30 minutes to two hours after eating or drinking foods that contain lactose. Common signs and symptoms include:
• Nausea, and sometimes, vomiting
• Abdominal cramps
Lactose intolerance occurs when your small intestine doesn't produce enough of an enzyme (lactase) to digest milk sugar (lactose).
Normally, lactase turns milk sugar into two simple sugars – glucose and galactose – which are absorbed into the bloodstream through the intestinal lining.
If you're lactase deficient, lactose in your food moves into the colon instead of being processed and absorbed. In the colon, normal bacteria interact with undigested lactose, causing the signs and symptoms of lactose intolerance.
Types of lactose intolerance:
There are three types of lactose intolerance.
1. Primary lactose disease.
This is the most common type. People who develop primary lactose intolerance start life producing plenty of lactase – a necessity for infants, who get all their nutrition from milk. As children replace milk with other foods, their lactase production normally decreases, but remains high enough to digest the amount of dairy in a typical adult diet.
In primary lactose intolerance, lactase production falls off sharply, making milk products difficult to digest by adulthood. Primary lactose type is genetically determined, occurring in a large proportion of people with African, Asian or Hispanic ancestry. The condition is also common among those of Mediterranean or Southern European descent
2. Secondary lactose type
This form of lactose intolerance occurs when your small intestine decreases lactase production after an illness, injury or surgery involving your small intestine. Among the diseases associated with secondary type are celiac disease, bacterial overgrowth and Crohn's disease. Treatment of the underlying disorder may restore lactase levels and improve signs and symptoms, though it can take time.
3. Congenital or developmental intolerance
It's possible, but rare, for babies to be born with disease caused by a complete absence of enzyme activity. This disorder is passed from generation to generation in a pattern of inheritance called autosomal recessive, meaning that both the mother and the father must pass on the same gene variant for a child to be affected.
Factors that can make you or your child more prone include:
• Increasing age. usually appears in adulthood. The condition is uncommon in babies and young children.
• Ethnicity. most common in people of African, Asian, Hispanic and American Indian descent.
• Premature birth. Infants born prematurely may have reduced levels because the small intestine doesn't develop lactase-producing cells until late in the third trimester.
• Diseases affecting the small intestine. Small intestine problems that can cause this disease include bacterial overgrowth, celiac disease and Crohn's disease.
• Certain cancer treatments. If you have received radiation therapy for cancer in your abdomen or have intestinal complications from chemotherapy, you have an increased risk.
This gauges your body's reaction to a liquid that contains high levels. Two hours after drinking the liquid, you'll undergo blood tests to measure the amount of glucose in your bloodstream. If your glucose level doesn't rise, it means your body isn't properly digesting and absorbing the lactose-filled drink.
• Hydrogen breath test.
This test also requires you to drink a liquid that contains high levels. Then your doctor measures the amount of hydrogen in your breath at regular intervals. Normally, very little hydrogen is detectable. However, if your body doesn't digest the protein, it will ferment in the colon, releasing hydrogen and other gases, which are absorbed by your intestines and eventually exhaled. Larger than normal amounts of exhaled hydrogen measured during a breath test indicate that you aren't fully digesting and absorbing lactose.
• Stool acidity test.
For infants and children who can't undergo other tests, a stool acidity test may be used. The fermenting of undigested protein creates lactic acid and other acids that can be detected in a stool sample.
There's currently no way to boost your body's production, but you can usually avoid the discomfort of lactose intolerance by:
• Avoiding large servings of milk and other dairy products
• Including small servings of dairy products in your regular meals
• Eating and drinking protein-reduced ice cream and milk
• Drinking regular milk after you add a liquid or powder to it to break down the lactose.
Maintain good nutrition
Reducing the dairy products doesn't mean you can't get enough calcium. Calcium is found in many other foods, such as:
• Calcium-fortified products, such as breads and juices
• Canned salmon
• Milk substitutes, such as soy milk and rice milk
• Pinto beans
Limit dairy products
• Choosing smaller servings of dairy.
Sip small servings of milk – up to 4 ounces (118 milliliters) at a time. The smaller the serving, the less likely it is to cause gastrointestinal problems.
• Saving milk for mealtimes.
Drink milk with other foods. This slows the digestive process and may lessen symptoms.
• Experimenting with an assortment of dairy products.
Not all dairy products have the same amount of protein. For example, hard cheeses, such as Swiss or cheddar, have small amounts of protein and generally cause no symptoms. You may be able to tolerate cultured milk products, such as yogurt, because the bacteria used in the culturing process naturally produce the enzyme that breaks down lactose.
• Buying lactose-free products.
You can find these products at most supermarkets in the refrigerated dairy section.
• Using enzyme tablets or drops.