See what questions
a doctor would ask.
Article title: Lactose Intolerance: NWHIC
Conditions: Lactose Intolerance
What is lactose
What are the symptoms of lactose intolerance?
Who is affected by lactose intolerance?
What causes lactose intolerance?
How is lactose intolerance diagnosed?
How can I treat the symptoms of lactose intolerance?
What kinds of foods besides diary products can contain lactose?
How can I get enough calcium in my diet if I am lactose intolerant?
Lactose intolerance is a condition in which the body is not able to easily digest foods that contain lactose, or the natural sugar that is found in dairy products. Once lactose is in the body, it needs to be broken down into two simple sugars, glucose and galactose, to be absorbed into the blood stream. People who are lactose intolerant have a shortage of lactase enzymes that break down lactose into these sugars.
Even though lactose intolerance is not a dangerous health condition, the symptoms can be very uncomfortable. Gas, bloating, stomach cramps, diarrhea, and nausea are the most common symptoms. These symptoms may begin within as little as 30 minutes or up to two hours after eating or drinking foods that contain lactose. The severity of symptoms is different for each person, and depends on how much lactose a person can tolerate. Recent studies have found that many people who have lactose intolerance can have one serving of milk with a meal or two servings of milk per day, at separate times, without experiencing symptoms. People also may be able to tolerate food like aged cheese, which has less lactose, or yogurt, which has bacteria that digests lactose. Some experts believe that people who are sensitive to milk products, but can digest them in small quantities without experiencing severe gastrointestinal symptoms, are not lactose intolerant, but have lactose maldigestion. These people may produce lactase in very small amounts, but enough to allow them to digest very small amounts of dairy products.
An estimated 30 to 50 million Americans (about 25% of the United States population) are affected by lactose intolerance. While this condition is least common among Caucasians (about 15% of adults), it is widespread among other ethnic groups. It is estimated that 70% of African-American, 74% of Native American, 53% of Mexican-American, and 90% of Asian American adults are affected.
In most cases, lactose intolerance develops slowly over time. In many people, the body begins to produce less lactase beginning around two years old. As these people become older, they lose the ability to produce lactase, but symptoms of lactose intolerance may not appear until well after childhood. No one knows why this occurs. In other cases, certain digestive diseases or injuries to the small intestine can cause lactose intolerance. Both can reduce the amount of lactase produced by the lining of the small intestine. Another very rare cause is being born without the ability to produce lactase.
If you think that you are lactose intolerant, it is important to have a doctor diagnose you because your symptoms could be a sign of a different, or more serious, illness. There are three tests used to determine if a person has lactose intolerance: the lactose tolerance test; the hydrogen breath test; and the stool acidity test. All of these tests are performed on an outpatient basis.
The lactose tolerance test is a blood test that measures the amount of glucose in the blood before and after the patient drinks a large amount of liquid containing lactase. The patient is required to fast before the test. The hydrogen breath test measures the amount of hydrogen in the breath. The patient has to fast overnight and again at regular intervals after taking a dose of lactose. If the lactose is not digested, it produces hydrogen and other gases in the stomach. These gases travel through the body to the mouth and can be detected in the breath. The stool acidity test detects acids created by undigested lactose.
There are simple ways a person can deal with the uncomfortable symptoms of lactose intolerance. Although there is no known way to increase the amount of lactase in a person's body, there are supplements people can take before eating or drinking dairy products. These lactase supplements come in both liquid and pill form and are available over-the-counter at pharmacies and grocery stores. Lactose-reduced products also are available for most kinds of diary products, including milk, cheese, and ice cream.
The easiest and least expensive way to control symptoms is to avoid foods containing lactase. Adults can test the kinds and quantities of foods their systems are able to handle, then avoid the foods and amounts that produce bothersome symptoms. Infants and children, on the other hand, should not be given food that contains lactose if they have an allergy to milk products. Studies show that for people who have at least some lactase, they can increase tolerance to dairy products by introducing them gradually into the diet. Again, they also can eat more easily digested dairy products such as yogurt and aged cheese.
It is important to read the label of ingredients on foods since many foods other than those made with milk may contain lactose. Examples of these include: bakery products; cereals; instant potatoes, soups, and breakfast drinks; margarine; non-Kosher lunch meats; salad dressings; candies; mixes for pancakes, biscuits, and cookies; artificial sweeteners; hot chocolate mixes; cream cheese and peanut butter with milk solid filler; omelets, scrambled eggs and soufflés at restaurants; and gelatins made with an ingredient called carageenan. Many prescription drugs also contain lactose. A pharmacist can answer specific questions about which drugs contain lactose, but some of them include birth control pills and tablets for stomach acid and gas.
Calcium is necessary for strong and healthy bones throughout life. A lack of calcium in the diet can lead to osteoporosis, or a condition of fragile, weakened bones that can break easily. Dairy products, like low-fat milk, are the best source of calcium. If you are lactose intolerant, it is important to have a diet that includes other foods high in calcium to meet the recommended daily amounts.
Other foods high in calcium include dark, green leafy vegetables, like kale and broccoli, fish like salmon, sardines, and oysters (or those with soft, edible bones), and tofu. Although these foods are high in calcium, the body cannot absorb it as easily as from milk. For instance, it takes 11-14 servings of kale a day to get the same amount of calcium in three to four glasses of milk. Click here for more information on calcium.
Eating foods fortified with calcium, like certain cereals and orange juice, and taking calcium supplements also can help you reach your optimal calcium intake. Since there are several types of calcium supplements available, you should discuss the choice of supplements with your doctor. Taking lactase supplements before meals and eating lactose-free products high in calcium are other options.
You can find out more about lactose intolerance by contacting the National Women’s Health Information Center and the following organizations:
National Institute of Child Health and Human Development Clearinghouse,
Milk Matters Campaign
Internet Address: http://www.nichd.nih.gov/
National Institute of Digestive Diseases Information Clearinghouse,
Phone: (301) 654-3810
Internet Address: http://www.niddk.nih.gov/health/digest/nddic.htm
Osteoporosis and Related Bone Diseases National Resource Center, NIAMS,
Phone: (800) 624-2663, (202) 466-4315 (TDD)
Internet Address: http://www.osteo.org/
Food and Nutrition Information Center, USDA
Phone: (301) 504-5414
Internet Address: http://www.nal.usda.gov/fnic/
The American Dietetic Association
Phone: (800) 366-1655 (Consumer Nutrition Hotline), (800) 745-0775 (Publications Service)
Internet Address: http://www.eatright.org/
Publication date: April 2001
Search Specialists by State and City