Lactose Intolerance

Young women's version of this guide

You likely know someone with lactose intolerance. Perhaps that person is a family member, a friend, or you. Lactose intolerance is most common among Asian Americans, African Americans, individuals of Jewish descent, Mexican-Americans, and Native Americans. However, any person can have lactose intolerance.

What is lactose?

Lactose is a natural sugar found in milk and other dairy products. Your body makes an enzyme called lactase that breaks down the lactose in foods and drinks you consume into smaller sugars that your body can then digest and use for energy.

What is lactose intolerance?

If you have lactose intolerance, your body may not be able to break down all the lactose that you eat or drink. People with lactose intolerance do not produce sufficient amounts of lactase needed to break down the lactose. This causes undigested lactose to make its way to the large intestine where bacteria start to digest it. This can cause nausea, stomach cramps, gas, bloating, and diarrhea for people with lactose intolerance if they eat or drink a certain amount of milk or other lactose-containing foods.

How can I tell if I have lactose intolerance?

If you have nausea, stomach cramps, gas, bloating, or diarrhea within 30 minutes to several hours after eating or drinking foods with lactose, you may have lactose intolerance.

What should I do if I think I have lactose intolerance?

Do not try to diagnose yourself. If you think you might be lactose intolerant, it’s important to share your concern with your health care provider. The same discomfort caused by lactose intolerance could also be caused by other health conditions. Your health care provider is the only person who can confirm whether or not you are lactose intolerant. Once your health care provider figures out what is causing your digestive discomfort, you can work with them or a dietitian to manage your symptoms.

How can my health care provider tell if I’m lactose intolerant?

Your health care provider will likely ask you a number of questions about your symptoms and what a typical day of eating looks like. For some individuals, the first suggestion from a health care provider to confirm a lactose intolerance diagnosis is to stop eating or drinking foods with lactose and to see if your symptoms improve. You may also have a hydrogen breath test to confirm a lactose intolerance diagnosis. A hydrogen breath test is done by breathing into a machine that measures the amount of hydrogen in your breath within 90 minutes of consuming lactose. If you have lactose intolerance, your body will produce more hydrogen than if you are about to tolerate lactose.

Can some people be more lactose intolerant than others?

Yes, there are different degrees of lactose intolerance. For example, some people may be symptomatic after drinking 1/2 cup of milk, while others may only get symptoms only when they drink 1 cup. Other people may have difficulty drinking even less than 1/2 cup of milk. Over time, you will learn what quantity of milk and other dairy products your body can handle without having symptoms.

Are there different “types” of lactose intolerance?

Yes. Some people are born without the ability to make the enzyme lactase. People with this type of lactose intolerance have the most difficulty drinking or eating foods that contain lactose. More commonly, people become lactose intolerant as they grow older and their body slowly makes less and less lactase. Furthermore, some people become lactose intolerant after having surgery or a gastrointestinal infection.

Will I always be lactose intolerant?

If you became lactose intolerant because of an illness, most likely you will not be lactose intolerant forever. If you were born with lactose intolerance or you are having more trouble digesting milk products than you did when you were younger, it’s possible that you may always have some degree of lactose intolerance.

What should I do if I’m lactose intolerant?

If your health care provider has told you that you are lactose intolerant, there are several things you can do so you won’t feel gassy, bloated, or have stomach cramps or diarrhea after you eat lactose-containing foods.

Try these helpful tips:

  • Know what foods and drinks contain lactose. Lactose is in most dairy products, some baked and processed foods such as bread, dry cereal, candy, cookies, salad dressings, cream soups, drink mixes, and prepared foods like pizza and lasagna.
  • Pay attention to food labels. Food labels list all of the ingredients in order of the amount. The ingredients included in the largest amounts are listed first while those at the end of the list are in the smallest amounts. For example, if milk is listed first, you know that the product contains mostly milk. If you are lactose intolerant, this may be a product that you want to avoid or consume in small amounts.
  • Start with small portions of dairy foods. If you can tolerate small portions, you might be able to add more, a little at a time. As you slowly add dairy foods over time, you will be able to figure out how much lactose your body can handle.
  • Combine dairy foods with nondairy foods. Eating dairy foods with other foods slows the release of lactose into your body. This makes it easier for your body to digest and breakdown the lactose.
  • Eat smaller portions of milk or dairy products more frequently. Instead of drinking full servings (1 cup or 8 ounces) of milk, try drinking smaller servings (1/2 cup or 4 ounces) throughout the day.
  • Eat dairy foods that are naturally lower in lactose. Cheese and yogurt generally have less lactose than milk. This is because the lactose is partially broken down during the aging process in cheese and by the bacteria in yogurt. Specifically, aged hard cheeses like parmesan, Swiss, and cheddar, and yogurts that say “live active cultures” on the label tend to be low-lactose dairy options.

What if these suggestions don’t work?

If you still have discomfort after trying out these ideas, you may try a lactase supplement, such as Lactaid® or a generic brand, before having foods that contain lactose. You can buy the lactase supplement as a chewable pill or liquid drops. The supplement can be purchased without a prescription and will help your body to break down the lactose in the foods you eat or drink. You can also enjoy milk or ice cream that is labeled as lactose -free. The brand Lactaid® sells dairy products with the enzyme lactase already added into their foods, so this can also be helpful if your body has a hard time tolerating even small amounts of lactose.

Should I just omit dairy altogether?

Dairy is an important food group to have in your diet because it has many vitamins and minerals in it, including high amounts of calcium, vitamin D, and protein. While you can get these nutrients in other ways, dairy is an easy way to get all the calcium and vitamin D necessary for strong bones and overall health. If you are considering avoiding dairy altogether, you may need additional supplementation or alterations to what you eat. For example, almond milk tends to be very low in protein so is not an adequate substitute for dairy milk. Always speak to your health care professional before omitting any food group, so you can get all of the facts in addition to a proper diagnosis.

What else do I need to know?

  • Learn about secret ingredients that contain lactose. These ingredients include dry milk solids (including non-fat milk solids), buttermilk, malted milk, sour or sweet cream, margarine, whey, whey protein concentrate, and cheese. Sauces, dressings, and soup often have lactose. Baked and processed foods such as cookies, cakes, and pancakes may also contain lactose. Always check your food labels, and keep in mind you may be able to tolerate some of these foods.
  • Some medications contain lactose. Ask your health care provider if lactose is in any medications that you might be taking and read the label yourself, too.
  • Remember the calcium. If you don’t drink milk you need to make sure you’re getting enough calcium from other sources in your diet.
If you’re lactose intolerant, you probably won’t need to completely cut out milk or other dairy foods from your diet. These foods provide calcium and other important nutrients for your body. Managing your lactose intolerance with support may be easier than you think.