Milk and other dairy products are excellent sources of the calcium, the mineral that everyone needs to build and maintain strong bones. However, many people with Crohn’s disease avoid dairy for fear that it will cause uncomfortable symptoms, such as excess gas, abdominal cramping, and diarrhea. While it’s true that dairy can trigger these symptoms in some people, it’s usually because they are lactose intolerant.

People who are lactose intolerant have trouble digesting a type of sugar known as lactose. Lactose is found exclusively in milk and milk products. Humans are born with the ability to break down lactose into smaller, more digestible components. This initial step in digestion is achieved with the help of an enzyme called lactase. Lactase is tailored to break down the lactose molecule into smaller constituents, which are then absorbed by the intestines.

Many adults, however, lose the ability to produce lactase. This makes it difficult for their bodies to digest products containing lactose. As a result, people with lactose intolerance may experience some unpleasant intestinal discomfort when they consume dairy. The level of intolerance can vary from person to person. Some people may consume milk and milk products in small quantities and not experience any problems. Others may be very lactose intolerant and need to take supplemental lactase pills to help them digest dairy products properly.

Though dairy can cause digestive issues in people with lactose intolerance, it isn’t necessarily something that people with Crohn’s disease need to avoid. Even if someone with Crohn’s disease is lactose intolerant, it’s possible to safely consume certain dairy products that contain very little lactose. These include:

  • yogurt
  • clarified butter
  • aged and hard cheeses, such as Parmesan and aged cheddar

Dairy is often one of the first foods that people with Crohn’s disease eliminate from their diets. However, not every person with Crohn’s is actually lactose intolerant, so avoiding all dairy may not be necessary. It could even be counterproductive because dairy is an excellent source of calcium. This is a particularly important nutrient for people with Crohn’s disease, as certain drug treatments and malabsorption may cause a calcium deficiency.

Rather than avoiding dairy products unnecessarily, it may be better to try an elimination diet. An elimination diet is an approach that may help identify food allergies or food intolerances. You keep a food journal for several weeks, taking note of every food you eat and how you feel after eating it. You also take note of how much of the food you ate and when you ate it.

Tracking your progress should help you identify which foods trigger symptoms. Once you’ve found potential triggers, remove them from your diet for anywhere from two weeks to two months. If symptoms disappear, it can be assumed that you have an intolerance to the eliminated food. This can be confirmed by carefully adding the food back into your diet. If symptoms reappear, it can be assumed that the food isn’t well-tolerated. If symptoms persist during the elimination phase, it can be assumed that the food isn’t part of the problem, and the food can be reintroduced into the diet.

Crohn’s disease is believed to be an autoimmune disease that causes the lining of the digestive tract to become inflamed. Though the exact cause for this inflammation isn’t known, experts agree that food doesn’t play a role in triggering it. In recent years, however, some scientists have proposed a possible link between the dairy industry and Crohn’s disease.

Here’s why: Cows can become infected with a microbe known as mycobacterium avium subspecies paratuberculosis (MAP). In cows, this germ is linked to an illness known as Johne’s disease. Like Crohn’s disease, the condition causes inflammation in the lining of the intestines. When someone ingests beef or milk contaminated with MAP, they can become infected with it as well. MAP is commonly found in people with Crohn’s disease, so some scientists now speculate that MAP may be a contributing factor to the development of the disease. While they don’t necessarily believe that the germ causes Crohn’s disease, they argue that it may trigger the inflammation and destruction of the intestinal lining.

The possible link between MAP and Crohn’s disease has yet to be proven and remains very controversial. If studies eventually do confirm the connection, the discovery could potentially lead to better treatments for the underlying MAP infection and any associated Crohn’s disease symptoms.