Dairy is thought to be linked to asthma. Drinking milk or eating dairy products doesn’t cause asthma. However, if you have a dairy allergy, it may trigger symptoms that are similar to asthma.

Also, if you have asthma and a dairy allergy, dairy may worsen your asthma symptoms. About 45 percent of children with asthma also have dairy and other food allergies. Children with food allergies are up to four times more likely to have asthma or other allergic conditions than children without a food allergy.

Both asthma and food allergies are set off by the same reactions. The immune system goes into overdrive because it mistakes a food or other allergen as an attacker. Here’s how dairy can trigger asthma symptoms and some of the milk myths that exist.

Asthma is a condition that makes the airways narrow and inflamed or irritated. Your airways or breathing tubes pass from the mouth, nose, and throat into the lungs.

Almost 12 percent of people have asthma. Both children and adults can have this lung disease. Asthma can be a long-lasting and life-threatening condition.

Asthma makes it difficult to breathe because it makes airways swollen and inflamed. They may also fill with mucus or fluid. Additionally, the round muscles that circle your airways may tighten. This makes your breathing tubes even more narrow.

Symptoms of asthma include:

  • wheezing
  • shortness of breath
  • coughing
  • chest tightness
  • mucus in the lungs

Milk and other dairy products won’t cause asthma. This is true whether you have a dairy allergy or not. Similarly, if you have asthma but not a dairy allergy, you can safely eat dairy. It won’t trigger your asthma symptoms or make them worse.

Medical research confirms that dairy isn’t related to worsening asthma symptoms. A study on 30 adults with asthma showed that drinking cow’s milk didn’t make their symptoms worse.

Additionally, a 2015 study found that mothers who ate a high amount of dairy products during pregnancy had babies with a lower risk of asthma and other allergy disorders, such as eczema.

The percentage of people with a dairy allergy is low. About 5 percent of children have a dairy allergy. Almost 80 percent of children grow out of this food allergy during childhood or the teenage years. Adults can also develop a dairy allergy.

Dairy allergy symptoms

A dairy allergy can cause breathing, stomach, and skin reactions. Some of these are similar to asthma symptoms, and include:

  • wheezing
  • coughing
  • shortness of breath
  • lip, tongue, or throat swelling
  • itching or tingling around the lips or mouth
  • runny nose
  • watery eyes

If these allergy symptoms happen at the same time as an asthma attack, they make it more difficult to breathe. Milk allergy symptoms also include:

  • hives
  • vomiting
  • upset stomach
  • stomach cramps
  • loose bowel movement or diarrhea
  • colic in babies
  • bloody bowel movement, usually in babies only

In serious cases, an allergic reaction to dairy can cause anaphylaxis. This leads to swelling in the throat and narrowing of the breathing tubes. Anaphylaxis can lead to low blood pressure and shock and requires immediate medical attention.

Milk and mucus

One reason that dairy may be linked to asthma is because it’s thought to cause more mucus in your body. People with asthma can get too much mucus in their lungs.

The National Asthma Council of Australia points out that milk and dairy don’t cause your body to produce more mucus. In some people with a dairy allergy or sensitivity, milk may thicken saliva in the mouth.

What causes a dairy allergy?

A dairy or milk allergy happens when your immune system goes into overdrive and thinks milk and dairy products are harmful. Most people with a dairy allergy are allergic to cow’s milk. Some people may also have a reaction against milk from other animals such as goats, sheep, and buffalo.

If you have a dairy allergy, your body is reacting against the proteins found in milk. Dairy contains two types of proteins:

  • Casein makes up 80 percent of milk protein. It’s found in the solid part of milk.
  • Whey protein makes up 20 percent of milk. It is found in the liquid part.

You may be allergic to both types of milk protein or just one. Antibiotics given to dairy cows may also be linked to milk allergies.

Foods with milk proteins

Avoid all milk and dairy products if you have a dairy allergy. Read food labels carefully. Milk proteins are added to a surprising number of packaged and processed foods, including:

  • beverage mixes
  • energy and protein drinks
  • canned tuna
  • sausages
  • sandwich meats
  • chewing gum

Dairy alternatives include:

  • coconut milk
  • soy milk
  • almond milk
  • oat milk

A milk or dairy allergy isn’t the same as lactose intolerance. Lactose intolerance is a food sensitivity or intolerance. Unlike milk or food allergies, it’s not linked to your immune system.

Adults and children who are lactose intolerant can’t digest lactose, or milk sugar, properly. This happens because they don’t have enough of an enzyme called lactase.

Lactose can only be broken down by lactase. Lactose intolerance mainly causes digestive effects, not respiratory ones. Some symptoms are similar to those that happen in a milk allergy:

  • stomach cramps
  • abdominal pain
  • bloating and gassiness
  • diarrhea

See your doctor if you have any kind of symptoms after drinking milk or eating dairy foods. An allergy specialist can do a skin test and other testing to find out if you have an allergy or dairy intolerance. Blood tests can also show if you have other food allergies.

Your doctor will also look at your medical history and your symptoms. Sometimes a test may not show that you have a food allergy. It may be useful to keep a food journal.

Another option is to try an elimination diet. This diet removes dairy for a few weeks then slowly adds it back in. Record all symptoms and let your doctor know.

Dairy allergy treatments

Dairy and other food allergies are treated by avoiding the food completely. Keep an epinephrine injection pen in your home, at school, or where you work. This is very important if you’re at risk of anaphylaxis.

Asthma treatments

Asthma is treated with prescription medications. You’ll likely need more than one kind of drug. These include:

  • Bronchodilators. These open up the airways to prevent or treat an asthma attack.
  • Steroids. These medications help balance the immune system and prevent asthma symptoms.

You can find delicious alternatives to dairy. Here are the nine best non-dairy substitutes for milk.

Asthma can be a life-threatening condition. See your doctor if you have any asthma or allergy symptoms. Attend all follow-up appointments and let your doctor know if you have any changes in your symptoms.

Dairy products don’t seem to worsen asthma in those without a dairy allergy. If you think you may have a dairy or other food allergy, tell your doctor immediately. Allergic reactions can trigger or worsen asthma symptoms in some people.

Talk to your doctor or nutritionist about the best diet plan for your asthma and allergies. Carry extra asthma medication and prescriptions with you at all times. A bronchodilator inhaler or an epinephrine injection pen can save your life if you have a serious reaction.