Overview Of Lactose Intolerance
Lactose is a type of sugar found in milk and other dairy products. An enzyme called lactase is needed by the body to digest lactose. Lactose intolerance develops when the small intestine does not make enough of this enzyme.
Commonly Associated With
Lactase deficiency; Milk intolerance; Disaccharidase deficiency; Dairy product intolerance; Diarrhea – lactose intolerance; Bloating – lactose intolerance
Causes Of Lactose Intolerance
Babies’ bodies make the lactase enzyme so they can digest milk, including breast milk.
Babies born too early (premature) sometimes have lactose intolerance.
Children who were born at full term often do not show signs of the problem before they are 3 years old.
Lactose intolerance is very common in adults. It is rarely dangerous. About 30 million American adults have some degree of lactose intolerance by age 20.
In white people, lactose intolerance often develops in children older than age 5. This is the age when our bodies may stop making lactase.
In African Americans, the problem can occur as early as age 2.
The condition is very common among adults with Asian, African, or Native American heritage.
It is less common in people of northern or western European backgrounds but still may occur.
An illness that involves or injures your small intestine may cause less of the lactase enzyme to be made. Treatment of these illnesses may improve the symptoms of lactose intolerance.
These may include:
- Surgery of the small intestine
- Infections in the small intestine (this is most often seen in children)
- Diseases that damage the small intestines, such as celiac sprue or Crohn disease
- Any illness that causes diarrhea
- Babies may be born with a genetic defect and are not able to make any of the lactase enzymes.
Symptoms Of Lactose Intolerance
Symptoms often occur 30 minutes to 2 hours after having milk products. Symptoms may be worse when you consume large amounts.
- Abdominal bloating
- Abdominal cramps
- Gas (flatulence)
Exams & Tests
Other intestinal problems, such as irritable bowel syndrome, may cause the same symptoms as lactose intolerance.
Tests to help diagnose lactose intolerance include:
- Lactose-hydrogen breath test
- Lactose tolerance test
- Stool pH
- Another method may be to challenge a patient with 25 to 50 grams of lactose in water. Symptoms are then assessed using a questionnaire.
- A 1 to 2 week trial of a completely lactose-free diet is also sometimes tried.
Treatment Of Lactose Intolerance
Cutting down your intake of milk products that contain lactose from your diet most often eases symptoms. Also, look at food labels for hidden sources of lactose in nonmilk products (including some beers) and avoid these.
Most people with low lactase levels can drink up to one-half cup of milk at one time (2 to 4 ounces or 60 to 120 milliliters) without having symptoms. Larger servings (more than 8 ounces or 240 mL) may cause problems for people with the deficiency.
Milk products that may be easier to digest include:
- Buttermilk and cheeses (these foods contain less lactose than milk)
- Fermented milk products, such as yogurt
- Goat’s milk
- Aged hard cheeses
- Lactose-free milk and milk products
- Lactase-treated cow’s milk for older children and adults
- Soy formulas for infants younger than 2 years
- Soy or rice milk for toddlers
- You can add lactase enzymes to regular milk. You can also take these enzymes as capsules or chewable tablets. There are also many lactose-free dairy products available.
- Not having milk and other dairy products in your diet can lead to a shortage of calcium, vitamin D, riboflavin, and protein. You need 1,000 to 1,500 mg of calcium each day depending on your age and sex. Some things you can do to get more calcium in your diet are:
- Take calcium supplements with Vitamin D. Talk to your health care provider about which ones to choose.
- Eat foods that have more calcium (such as leafy greens, oysters, sardines, canned salmon, shrimp, and broccoli).
- Drink orange juice with added calcium.