Lactose Intolerance in People with Down Syndrome

Key Points

• Lactose intolerance happens when the body cannot properly digest lactose, the sugar in cow’s milk.
• It can cause abdominal pain, bloating, gas, and other symptoms.
• It is unknown how common it is in people with Down syndrome.
• Treatment consists of avoiding lactose or taking a supplement with the enzyme to break down lactose and help digest it.

What is lactose intolerance?

Lactose is a sugar found in cow’s milk. It is made up of two molecules that are split apart by lactase, an enzyme in the small intestine. After they are split apart, the molecules can be absorbed through the intestinal wall.

If the molecules are not split apart, they cannot be absorbed. The undigested lactose sits in the intestine and ferments, which causes symptoms.

Lactose intolerance most often starts in the teenage or adult years.

Symptoms

Symptoms may include:

• Abdominal pain
• Bloating
• Gas
• Diarrhea
• Cramping
• Stomach rumbling

Symptoms usually start 30 minutes to 2 hours after eating or drinking foods that contain lactose. Many people with lactose intolerance can handle small amounts of lactose without symptoms, but larger amounts cause symptoms.

Lactose intolerance in people with Down syndrome

There is little published research about lactose intolerance in people with Down syndrome. The exact frequency of lactose intolerance in people with Down syndrome is not known. In our clinical experience, the condition affects many people with Down syndrome.

Some people with Down syndrome may not get diarrhea from lactose intolerance if they tend to be constipated. Other symptoms (like bloating, gas, or pain) may be more noticeable.

Additionally, celiac disease is more common in people with Down syndrome. Celiac disease can cause lactose intolerance. Starting a gluten-free diet may resolve the symptoms of lactose intolerance. If symptoms persist, the person may have both celiac disease and lactose intolerance. Both conditions need to be addressed in those individuals.

Diagnosis

A primary care professional or gastroenterology (GI) specialist can diagnose lactose intolerance. Diagnosis may include:

• Hydrogen breath test: The person drinks a solution with lactose, then breathes into a device that measures hydrogen. The person will breathe into the device multiple times over several hours. High hydrogen levels indicate that lactose is not being digested properly.
• Lactose intolerance blood test: A person’s blood sugar level is measured, then the person drinks a lactose solution, and then their blood sugar level is checked again. If blood sugar does not rise, it suggests the body is not absorbing the lactose.
• Dietary elimination: A person removes dairy products from their diet. If symptoms improve, lactose intolerance is suspected. To confirm lactose intolerance, the person can start eating dairy products again to see if symptoms return.

Treatment

Treatment can include:

Avoiding dairy foods that cause symptoms

• Foods to avoid include milk, cheese, ice cream, and packaged foods (like some cereals) that contain milk or lactose.
• Many people cannot eat these foods even when they are cooked or baked.
• Yogurt and fermented dairy products such as hard cheeses may be easier to tolerate.

Buying lactose-free products

• Some food and drink products are pre-treated with lactase to break down the lactose.
• For example, lactase-treated milk is available in grocery stores.

Taking lactase supplements

• The lactase enzyme is available in pill and liquid forms.
• It can be taken before eating foods containing lactose to avoid symptoms.

Additional considerations

• Consider taking a calcium and vitamin D supplement to make up for the calcium that is not being consumed by avoiding dairy products.
• A probiotic may help reduce symptoms of lactose intolerance for some people.

Intolerance of other foods

Some individuals with Down syndrome report gastrointestinal symptoms (like diarrhea, bloating, or cramping) after eating various other foods. We have not identified any specific patterns – it seems to vary by person.

If other causes of gastrointestinal symptoms have been ruled out and no clear trigger is found, keeping a food and symptom diary may help. This involves recording everything a person eats or drinks throughout the day and any symptoms that follow.

Some cautions with this approach:

• Look for patterns. Avoid making conclusions about a particular food or drink after a single episode. Observe at least a few times before concluding that the food or drink is the source of the symptoms.
• After eliminating a food, consider reintroducing it to the diet later to see if it still causes the symptoms.
• Avoid cutting out too many foods, which can lead to restrictive eating habits or vitamin and nutrient deficiencies.

Dieticians can help in identifying problematic foods and developing a balanced diet to avoid vitamin and nutrient deficiencies.

Resources

Down Syndrome

Celiac Disease

Use of Probiotics by People with Down Syndrome

General

Lactose Intolerance (Cleveland Clinic)