Woman with hand raised in front of milk, symbolizing food intolerance or allergy avoidance

Often, the terms “food allergy” and “food intolerance” are used interchangeably – but are they really the same thing? If not, how can you tell the difference?

While both conditions can cause discomfort, food allergies and food intolerances are very different, and the distinction lies in how the body responds. Food allergies trigger an immune response, which can be severe and even life-threatening, while food intolerances cause a gastrointestinal (GI) response that, although uncomfortable, is typically not dangerous.

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What is Food Intolerance?

A food intolerance primarily involves the digestive system. When certain foods aren’t properly broken down in the body – often due to enzyme deficiencies or reactions to food additives – it can lead to gastrointestinal distress. The effects of food intolerances, such as stomach cramps, bloating, increased inflammation, skin rashes (like eczema), diarrhea, and constipation, are unpleasant but generally not life-threatening.

Unlike food allergies, individuals with food intolerances can often consume small amounts of the food without symptoms. For example, someone with lactose intolerance might be able to eat a small scoop of ice cream without any negative effects. It’s estimated that up to 20% of the global population suffers from food intolerances, and the numbers seem to be rising.

Common Food Intolerances

Common food intolerances include:

Lactose (found in dairy products)
Gluten (found in wheat and other grains, but distinct from Celiac disease, which is an autoimmune disorder)
Eggs
Soy
Food additives like sulfites

Assortment of common food allergens including nuts, milk, and seafood with food allergy sign

What is a Food Allergy?

Unlike food intolerance, a food allergy impacts the immune system and can have serious health implications. When someone has a food allergy, their immune system mistakenly identifies a specific food as a threat and launches an attack. This response involves the release of IgE antibodies, which trigger allergic symptoms.

The symptoms of a food allergy can appear very quickly, often within minutes to an hour of exposure. While mild reactions may cause hives or stomach discomfort, severe reactions can result in anaphylaxis – a potentially fatal condition that requires immediate medical attention. According to the CDC, approximately 4% of adults have food allergies.

Symptoms of Food Allergy

Hives or skin rash
Swelling of the lips, tongue, or throat
Difficulty breathing, wheezing, or shortness of breath
Nausea, vomiting, and abdominal pain
Weak pulse or dizziness

Example: Peanut allergies are a common food allergy, and reactions can be severe. Parents are often cautioned not to send peanut-containing foods to school, as even a small amount of exposure can trigger a life-threatening response in allergic children.

What Foods Commonly Cause Food Allergies?

While food intolerances are widespread, food allergies are less common but can be much more dangerous. The following nine food categories are responsible for about 90% of all food allergies:

Peanuts
Tree nuts
Fish
Shellfish
Eggs
Cow’s milk
Soy
Wheat
Sesame

Even a tiny amount of these foods can cause severe reactions in allergic individuals. Unlike intolerances, where symptoms are consistent, food allergies can escalate unexpectedly; a previously mild reaction could turn life-threatening with the next exposure.

What is the difference between food intolerance vs. food allergy?

To better understand the differences between food intolerance and food allergy, here’s a side-by-side comparison:

	Food Intolerance	Food Allergy
Response System	Digestive system	Immune system
Intensity of Reaction	Mild to moderate discomfort	Can be life-threatening
Symptoms	Gastrointestinal (nausea, bloating, diarrhea)	Multi-system (skin, respiratory, GI, cardiovascular)
Reaction Time	Often delayed	Immediate (within minutes to an hour)
Action to Take	See a healthcare provider for management	Carry epinephrine and call 911 if severe

Assorted foods including fish, nuts, and dairy products, representing foods related to intolerance and allergies

How Are Food Intolerances and Food Allergies Treated?

Treatment for Food Intolerance

For those with food intolerances, managing symptoms often involves dietary adjustments. For example, individuals with lactose intolerance can take lactase enzyme supplements to help break down lactose in dairy products. Working with a healthcare provider can help determine the best approach to minimize discomfort and improve quality of life.

Treatment for Food Allergy

In the case of a food allergy, strict avoidance of the allergen is crucial. Individuals with severe allergies should carry an epinephrine auto-injector at all times and know how to use it in an emergency. If you or your child has a food allergy, consulting with an allergist can provide personalized guidance on managing and treating the condition.

When to Seek Medical Help

If you suspect you have a food intolerance or allergy, consulting a healthcare provider is essential for accurate diagnosis and management. Testing options include elimination diets and allergy tests (like skin prick tests and blood tests), which can help determine whether a reaction is due to an intolerance or an immune-based allergy.

For those experiencing life-threatening symptoms like difficulty breathing, facial swelling, or anaphylaxis, immediate medical attention is necessary. Call 911 and use an epinephrine auto-injector if available.

Conclusion

Understanding the difference between food intolerance and food allergy is key to managing symptoms and making safer food choices. While intolerances primarily cause digestive discomfort, food allergies can trigger severe immune reactions and require vigilant avoidance of allergens.

At SageMED, our knowledgeable physicians are here to help you identify food intolerances or allergies through comprehensive testing and personalized advice. Take control of your diet and health today by scheduling an appointment with our expert team. Understanding your body’s unique responses is the first step toward better health.

O'Brien, A. (2019, July 8). What's the Difference Between a Food Allergy, Sensitivity, and Intolerance? Retrieved from https://www.oregonclinic.com/about-us/blog/what’s-difference-between-food-allergy-sensitivity-and-intolerance
Food Allergy vs Food Intolerance. Cleveland Clinic. (2015, May 5). Retrieved from https://my.clevelandclinic.org/health/diseases/10009-food-problems-is-it-an-allergy-or-intolerance