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How to Tell If It’s a Food Allergy or Intolerance Causing Your Symptoms

If you don’t feel well after you eat something, you might assume you have a food allergy. It’s common for people who get symptoms after eating things like dairy products or foods that contain wheat to say they are “allergic” to those foods. 

But food allergies and food intolerances are not the same. We talked to Heather Cassell, MD, an allergy and immunology specialist at Diamond Children’s Multispecialty Services Clinic in Tucson, AZ, to learn more about the similarities and differences between these two health conditions.

What is a food allergy?

When you have a food allergy, your immune system responds to something you eat. You’ll have symptoms any time you eat or drink that food. “Immune responses to foods can be serious and even life-threatening, and even small amounts of the food can be dangerous,” Dr. Cassell said.

The most common culprits behind food allergies are:

  • Milk and dairy products
  • Eggs
  • Fish or shellfish
  • Peanuts, cashews or walnuts
  • Wheat
  • Soy

There are a lot of different factors that influence whether someone develops food allergies. “Genetic predisposition plays the largest role,” Dr. Cassell said. But nutrition, lifestyle, food exposures and hygiene can also play a part. 

If you have an allergic reaction to a food, you’ll probably develop symptoms within 30 minutes to two hours after contact with the suspected allergen. Symptoms could include:

  • Swollen lips, tongue or throat
  • Hives or a rash
  • Trouble swallowing or breathing

You’ll need emergency care for these symptoms since they can be life-threatening reactions. 

You can prevent triggering your food allergy by avoiding the food you’re allergic to. But, since food allergy symptoms can be fatal, it’s crucial that you have emergency medication—an epinephrine auto-injector (EpiPen)—on hand all the time just in case you’re accidentally exposed.

“There are also newer therapies for food allergies that can help protect you from having a life-threatening response if you’re exposed,” Dr. Cassell said. “But they don’t cure your allergies.”

If you think you have a food allergy, you should see an allergist or immunologist for a diagnosis. Dr. Cassell doesn’t recommend the over-the-counter allergy test kits you can buy. “They can cause confusion and lead you to eliminate foods from your diet unnecessarily,” she said. 

Food allergies affect more than just your diet and your physical health. It can be expensive to prevent and treat them, and they can be an emotional burden for people who have them. 

“Please be respectful of people with food allergies, since it is very difficult to understand how burdensome this diagnosis can be. Anxiety is common when navigating food allergies since an accidental exposure could be deadly. And children with food allergies are often bullied at school and excluded from group activities,” Dr. Cassell said. “Thoughtfulness and kindness go a long way.”

What is a food intolerance?

With a food intolerance, also called a food sensitivity, your digestive system has an adverse reaction to something you eat. Symptoms of food intolerances are unpleasant but usually not dangerous. You might be able to eat or drink a small amount of the food without any problems, but larger amounts could cause symptoms.

People often have food intolerances to:

  • Dairy products (lactose intolerance)
  • Gluten
  • Caffeine
  • Fermented or cured foods
  • Foods that contain sulfites
  • Fructose, including high-fructose corn syrup and many types of fruit

Symptoms of a food intolerance are generally centered around your gastrointestinal system. You may notice:

  • Gas or bloating
  • Nausea or an upset stomach
  • Diarrhea
  • Heartburn
  • Stomach pain

Avoiding the food that causes symptoms may be all the treatment you need for mild food intolerances. If you need to treat your symptoms or you want to be sure that a food intolerance is what’s causing them, reach out to your health care provider for guidance.

What about celiac disease?

Celiac disease is an immune-system response to gluten, which is found in wheat, rye and barley. It’s in a class by itself—it’s not the same as a wheat allergy or a wheat/gluten intolerance. It can cause diarrhea, abdominal or joint pain, fatigue and other symptoms. “If you have celiac disease, you have to avoid all gluten—you can develop symptoms with even the smallest exposure,” Dr. Cassell said. 

The bottom line

People often confuse food allergies and food intolerances, but they are not the same. It’s essential to understand the difference so you can treat them properly. If you would like to connect with a specialist, reach out to Banner Health by visiting bannerhealth.com.

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Food Allergies Nutrition