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The Difference Between Food Allergy and Food Intolerance

The Food Allergy and Research Education reports that up to 85 million Americans are affected by food allergies and intolerances, roughly 32 million of which are food allergies.  

Food allergies and intolerances impact different parts of the body. A food allergy is a medical condition in which exposure to a certain food triggers a harmful response from the immune system.

A food intolerance is when a person has difficulty digesting a particular food, leading to symptoms like intestinal gas, abdominal pain or diarrhea. Food intolerances can be caused by any number of factors, such as the absence of an enzyme needed to fully digest food that can cause lactose intolerance, irritable bowel syndrome, sensitivity to food additives and celiac disease.

Food intolerance symptoms are generally less serious than food allergy symptoms, which include:

  • Abdominal pain, diarrhea, nausea or vomiting
  • Dizziness, lightheadedness, or fainting
  • Hives, itching or eczema
  • Swelling of the lips, face, tongue and throat or other parts of the body
  • Tingling or itching in the mouth
  • Wheezing, nasal congestion or trouble breathing

Celiac disease vs. gluten intolerance

Gluten intolerance – or non-celiac gluten sensitivity (NCGS) – is not the same as celiac disease. Here are the key differences between the two:

  • Celiac disease: a serious autoimmune disease that causes an abnormal immune response to gluten, a protein found in wheat, barley and rye. Ingesting even a small amount of gluten can cause intestinal damage. Someone with celiac disease must completely avoid eating gluten for their entire life.
  • Gluten intolerance: a sensitivity that involves how the digestive system handles gluten. Someone with gluten intolerance may see symptoms improve by reducing how much gluten they consume.

The two are often confused with another because they share some of the same symptoms after eating gluten, including bloating, stomach pain and diarrhea.

Foods commonly associated with food allergies and intolerances

Eight major food allergens are responsible for roughly 90% of the serious food allergy reactions in the U.S.:

  • Crustacean shellfish (including crab, crayfish, lobster and shrimp)
  • Eggs
  • Fish
  • Milk
  • Peanuts
  • Soy
  • Tree nuts (including almonds, pecans and walnuts)
  • Wheat

Even small amounts of these foods can trigger a reaction, which can happen immediately after eating. Children are generally more likely to outgrow allergies to milk, eggs and soy than allergies to peanuts, fish and shrimp.

Sesame is also becoming a common food allergy in childhood. According to the National Institutes of Health, only 20% to 30% of children with a sesame allergy outgrow it.

Stay safe when dining out and on the go

  • Restaurant styles to avoid: Certain restaurants are riskier than others for people with food allergies or intolerances. Depending on a person’s allergies, those can include buffets, bakeries and restaurants that serve pre-made foods, as the risk for cross-contact in these settings is high.
  • Consider chains when traveling: Since most chain restaurants use the same ingredients and prepare menu items the same way, a person with allergies or intolerances is more likely to know what to expect when traveling or stopping to grab a bite in a pinch.
  • Communicate with servers: Talk with restaurant employees who can break down the ingredients a certain dish contains and what that dish is cooked in. For example, some restaurants may fry vegetarian items in the same fryer oil they fry fish in – which could potentially affect someone who is allergic to fish. Avoiding fried foods when out and about is generally a safe bet for this reason.
  • Be wary of desserts: Desserts can be a source of hidden allergens. Since many restaurants order their desserts from specialty shops, the staff may not be able to provide a complete list of ingredients, which makes it risky to order desserts at a restaurant or café.

Shanthi Appelö is a registered dietitian and health and wellness spokesperson at Blue Cross Blue Shield of Michigan. For more health tips and information, visit AHealthierMichigan.org.