Digestive Disorders Health Center

What Is Lactose Intolerance?

Milk is the first food babies eat; it's considered one of the healthiest foods for you. So imagine having cramps just because you ate cereal for breakfast or passing gas following an ice cream treat. That's what it can be like to have lactose intolerance.

Lactose is the major sugar in milk and other dairy products. People with lactose intolerance can't digest lactose well. Lactose intolerance is not curable, but there are many ways to reduce symptoms and feel better.

What Are the Symptoms of Lactose Intolerance?

At least 30 minutes after eating a dairy product, but before two hours have passed, people with lactose intolerance have one or more of these symptoms. Symptoms can be mild or severe.

• Bloating
• Cramps
• Diarrhea
• Painful gas
• Nausea

Each person tolerates a certain amount of lactose, which affects how quickly he or she has symptoms and how severe they are. Some people may be sensitive to small amounts of lactose-containing foods, while others can eat larger amounts before they notice symptoms.

Which Foods Have Lactose?

Dairy products such as milk and ice cream are some of the most common foods high in lactose. It's also in foods with dry milk solids, milk byproducts, nonfat dry milk powder, or whey, including:

• Breads and baked goods
• Candy
• Cereals
• Salad dressings

In addition to food, lactose is in some prescription medicines, including birth control pills, and in some over-the-counter medicines, such as certain tablets to ease stomach acid or gas.

What Causes Lactose Intolerance?

People with lactose intolerance can't digest lactose, the major sugar found mostly in milk and other dairy products. The problem is they don't make enough of the enzyme that digests lactose -- lactase -- which the small intestine makes. So when they eat foods or take medicines with lactose, they have symptoms.

For many people, lactose intolerance develops naturally with age because the small intestine starts to make less lactase.

Reduced amounts of lactase may also be from an injured small intestine or certain digestive diseases, such as Crohn's disease or celiac disease.

Who Gets Lactose Intolerance?

Millions of Americans have lactose intolerance so it's quite common. About 75% of all people around the globe have some degree of lactase deficiency. African-Americans, Asians, Hispanics, and Native Americans have lactase deficits more than other races.

What Is Life Like With Lactose Intolerance?

Lactose intolerance is easy to manage. People with the condition usually find that they can tolerate a certain amount of lactose-containing foods without having symptoms. Some people use trial and error to figure out how much and what foods they can tolerate. There are many available lactose-free dairy options at your grocery store. Lactase enzyme supplements can also help you get the nutritional benefits of dairy, especially calcium and vitamin D, and avoid symptoms of lactose intolerance. In addition, nondairy beverages, such as soy, almond, and rice milk, are often fortified with the bone-building nutrients calcium and vitamin D.

If you or a loved one has lactose intolerance, keep these things in mind:

• Incorporating small amounts of milk or dairy products with meals may help because it's easier to digest lactose eaten with other foods.
• Certain dairy products are easier for people with lactose intolerance to digest, such as cheese, yogurt, and cottage cheese.
• Using lactose-free milk, cheese, and other dairy products in recipes will likely make the meal more pleasant.