Food Allergy vs. Intolerance: What’s the Difference?

Food Allergy | Food Intolerance | Key Differences | Managing Food Allergies & Intolerances

When it comes to food-related issues, the terms "food allergy" and "food intolerance" are often used interchangeably. However, they represent distinct conditions that require different approaches to management and treatment. Understanding the differences between food allergies and intolerances is crucial for making informed decisions about your health. This blog aims to clarify these differences and provide insights into identifying and managing each condition.

David Castor (dcastor), CC BY-SA 3.0 via Wikimedia Commons

What is a Food Allergy?

A food allergy involves the immune system. When someone with a food allergy eats even a small amount of the offending food, their immune system mistakenly identifies it as harmful and triggers an allergic reaction. This reaction can range from mild to severe and, in some cases, can be life-threatening (anaphylaxis).

The Food Allergy Research and Education (FARE)¹ organization recognizes nine major food allergens that can trigger a serious immune system response. These allergens are:

• Milk

• Eggs

• Fish (e.g., salmon, tuna, cod)

• Crustacean shellfish (e.g., shrimp, crab, lobster)

• Tree nuts (e.g., almonds, walnuts, cashews)

• Peanuts

• Wheat

• Soybeans

• Sesame (as of January 1, 2023, recognized by the FASTER Act²
  

Common Symptoms of Food Allergies

• Hives or itchy skin

• Swelling of the lips, face, tongue, or throat

• Difficulty breathing or wheezing

• Abdominal pain, nausea, vomiting, or diarrhea

• Anaphylaxis (a severe, potentially life-threatening allergic reaction)

What is Food Intolerance?

Food intolerance, on the other hand, does not involve the immune system. It occurs when the digestive system cannot properly break down certain foods³, often due to a lack of specific enzymes. While uncomfortable, food intolerance is generally less severe than a food allergy and is not life-threatening.

Common Symptoms of Food Intolerance

• Bloating and gas

• Abdominal pain or cramps

• Diarrhea

• Nausea

• Headaches or migraines

• Heartburn

Common Food Intolerances

• Lactose (found in dairy products)

• Gluten (found in wheat, barley, and rye)

• Amines (found in some foods and formed during food spoilage and fermentation like aged cheeses, processed meats, fermented beverages and some fruits & vegetables)

• Fructose (a type of sugar found in fruit and some vegetables)

• Certain food additives (such as sulfites and monosodium glutamate - MSG)

Food Allergy vs Intolerance: Key Differences

1. System Involvement

   1. Food Allergy (FA): Involves the immune system and can cause severe reactions.

   2. Food Intolerance (FI): A food intolerance reaction occurs in the digestive system.

2. Symptoms and Timing

   1. Food Allergy (FA): Usually appear quickly after consuming the allergen, often within minutes to a couple of hours.

   2. Food Intolerance (FI): Symptoms may take longer to develop, often several hours after eating the food.

3. Severity

   1. Food Allergy (FA): Can be life-threatening.

   2. Food Intolerance (FI): Usually causes discomfort but is not life-threatening.

4. Amount of Food

   1. Food Allergy (FA): Even a small amount can trigger a reaction.

   2. Food Intolerance (FI): The severity of symptoms is often dose-dependent, meaning larger quantities of the food may cause more severe symptoms.
      

Managing Food Allergies and Intolerances

Managing food allergies and intolerances involves different approaches.

1. Food Allergies:

   1. Strictly avoid foods that trigger allergic reactions.

   2. Always check food labels to identify allergens.

   3. Carry an epinephrine auto-injector (like an EpiPen) if you have severe allergies.

   4. Seek advice from an immunologist for personalized management.

2. Food Intolerances:

   1. Remove suspected foods from your diet for a set time to observe symptom improvement.

   2. Steer clear of foods that bother you.

   3. Some over-the-counter medications can help manage subtle cases of food intolerance.
      

REFERENCES

(1) Food Allergy Research & Education. (n.d.). Common allergens - peanut, egg, and sesame allergies: Fare. FoodAllergy.org. https://www.foodallergy.org/living-food-allergies/food-allergy-essentials/common-allergens

(2) Center for Food Safety and Applied Nutrition. (n.d.). The faster act: Sesame is the ninth major food allergen. U.S. Food and Drug Administration. https://www.fda.gov/food/food-allergies/faster-act-sesame-ninth-major-food-allergen

(3) Cleveland Clinic (n.d.). Food intolerance: Symptoms, causes and treatment options. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/21688-food-intolerance