Comprehensive Post-COVID Care Now Available! Click here to learn more.
Food Allergy vs Food Intolerance

Food Allergy vs Food Intolerance: Key Differences

It has been estimated that around 32 million Americans suffer from at least one form of food allergy.  Vague descriptions of food allergy make it quite difficult to segregate this condition from that of food intolerance. Several questions cause confusion when discussing both of these conditions, as several similarities exist in their presentations.

Food Allergy Vs Food Intolerance: What’s the difference?

So what’s the difference between a food allergy and food intolerance? An average person often makes the mistake of using the terms ‘food allergy’ and food intolerance’ synonymously, and we should not be blaming them. We do not see many sources breaking down the two very different themes for us, and even if they do, it causes further confusion; but here we will be getting into the nitty-gritty of how both these terms differ from each other in significantly important ways and how one can identify them correctly.

What is Food Allergy?

A food allergy is essentially an immunologic reaction. It happens when the cells of our immune system react to certain elements in the food we eat. Allergic reactions can range from mild weals and itching to anaphylaxis, which can be life-threatening. The culprits of the immune system causing allergic reactions are cells (mast cells, basophils) and a protein that our body synthesizes (immunoglobulin E- IgE).

Severity of Food Allergy:

-Mild allergic reactions: Mild allergic reactions can cause itching and the development of swollen red areas on the skin (weels). These are fairly benign and can easily be resolved with the help of over-the-counter medications or in some cases without medication too.  

-Severe allergic reaction: A severe allergic reaction causes the development of weals all over the body along with difficulty breathing and crampy abdominal pain. In the event of a severe allergic reaction, individuals should be given immediate medical care to prevent dreadful complications.

-Anaphylaxis: An anaphylactic reaction is potentially fatal. People experiencing anaphylaxis in response to a food allergen develop generalized uneasiness, severe shortness of breath, and blood pressure drops to a dangerous degree, which then requires urgent medical attention.

What is Food Intolerance?

While food allergy is the consequence of a hyperactive immune system; food intolerance is the result of the digestive system not accepting some food elements. People with food intolerance may experience physical symptoms of bloating, flatulence, diarrhea, and cramps after consumption of certain food products rather than cellular activation which occurs in allergic reactions.

Two most common food intolerances:

Lactose: Lactose is a type of sugar that is present in dairy products like milk, cheese, and yogurt. People intolerant to lactose lack the digestive enzyme (Lactase) essential to break down lactose, and food products prepared from dairy sources can cause bloating, cramping, and diarrhea in lactose-intolerant individuals.

Gluten: Gluten is a component of various grains like wheat, barley, and rye. Gluten intolerance- which is called celiac disease occurs when people cannot digest a component of gluten called gliadin. Consumption of grains causes severe diarrhea, crampy abdominal pain, and bloating, and in the long run, can lead to nutrient deficiencies and weight loss.

Key Differences

It is crucial to understand both, food allergy and food intolerance; so here’s a list of some of the significant differences between the twol:

1. Signs and Symptoms: Signs and Symptoms of food allergy involve multiple bodily systems causing skin involvement and development of wheals, respiratory difficulty, and blood pressure changes. Symptoms of food intolerance are only limited to the digestive system and present with bloating, cramping, diarrhea, and flatulence.

2.   Timing: An allergic reaction to a food product evolves almost immediately or within a few minutes of the consumption of the offending agent. However, symptoms of food intolerance evolve slowly over a few hours after the digestive system has had time to process the intolerant food product.

3.   Severity: Food allergy has the potential of causing life-threatening reactions which may even lead to death if not managed immediately (anaphylaxis). Food intolerance is generally mild and does not require immediate medical attention to prevent complications.

4.  Quantity of food: A food allergy can be triggered by the consumption of even the smallest amount of the offending agent (peanuts in ice cream). The development of food intolerance symptoms, however, depends on the quantity of the intolerant product consumed. Small quantities can be tolerated and may not cause any symptoms but consumption of larger quantities of a certain food product may cause significant symptoms.

List of Food Allergies

Some common food products that have been found to cause allergic reactions are:

  • Peanuts
  • Eggs (especially yolks)
  • Shellfish (oysters, scallops, crab, shrimp)
  • Soy
  • Sesame

Food Allergy in Children

The Southern California Food Allergy Institute has estimated that 1 in 13 children has some form of food allergy. Identifying food allergies in children is crucial when introducing new foods to their diets. It has been identified how critical food allergies are in children and to provide the best protective measures, the Food Allergen Labelling and Consumer Act (FALCPA) has made it mandatory to list all major food allergens including sesame to be made part of the label. It has been suggested that parents pay close attention to some foods as these are notorious for the accidental addition of food allergens.

  • Chewing gum (soy)
  • Marshmallows (shellfish)
  • Salad dressings and sauces (nuts)
  • Bread products (nuts)
  • Deli and processed meats (soy and lactose)

We may think that food allergies can only be triggered by eating certain food products, but that is not entirely true. Some household products may contain food components and that may lead to the development of allergic reactions.

Common products to be watchful of, to prevent food allergies include body lotions, body soaps (oils from nuts), chalk (lactose), crayons (soy), and playdoh (wheat).

Is Food Allergy Genetic

It has been found that food allergies do have a significant genetic component and children may inherit food allergies from their parents. The current hypothesis focuses on immune dysregulation which may be passed down to the offspring by their parents. However, where genetics have been identified as an important component in the development of food allergies, the influence of environmental factors cannot be ignored. It is the combination of both these aspects that leads to the development of various food allergies.

Managing Food Allergies

The easiest way to manage a food allergy is to stay away from the allergens. Keeping a close eye on the constituents of any food to prevent an allergic reaction is essential. However in the event that someone accidentally consumes an allergen, then management depends on the kind of reaction.

Mild reactions can resolve spontaneously or with the use of over-the-counter antihistamines. Severe reactions require urgent medical attention and anaphylaxis has to be managed with immediate administration of intramuscular epinephrine. It is advised that individuals report all known allergens to their physicians and people prone to an anaphylactic reaction to carry an epinephrine auto-injector at all times. Consultation with an allergist to better understand the responses of the immune system is a viable option too. They may be able to make recommendations that could allow the introduction of allergens into the diet without the development of troublesome symptoms.

Managing Food Intolerances

The first step in managing food intolerance is to identify the foods which trigger troublesome symptoms. Food products are complex and even the smallest amount of ingredients may be the culprit behind the symptoms of food intolerance. It is recommended to maintain a food diary and document the type of food and the kind of reaction elicited by the consumption of that food product. Elimination or consumption of a limited amount of the intolerant food product are the two options that are widely used by people to manage food intolerances. Consuming small amounts of the offending food product may cause mild symptoms or no symptoms at all and is done by most people trying to avoid nutrient deficiencies due to their food intolerance. People wanting to remedy such symptoms may benefit from over-the-counter antidiarrheals and antacids or may consult with their physician to better manage their symptoms.

Final Word

Newer research techniques and methods have improved our understanding of reactions caused by various food products. Lactose intolerant people can now easily take a lactase pill before consuming dairy; there are gluten-free products available for people who cannot consume grains and food labeling makes it easier to stay away from potentially harmful food products. And it doesn’t stop here. Some allergists are working tirelessly to better the quality of life for people who suffer from food allergies and food intolerances. We are sure there will be better therapeutic options available soon. Till then eat safe and stay safe!

– Disclaimer –
This blog is for informational & educational purposes only, and does not intend to substitute any professional medical advice or consultation. For any health related concerns, please consult with your physician, or call 911.

Medically Reviewed

Last reviewed by Dr. Syra Hanif, M.D. on 12/20/2021

Learn more about our editorial process.

  • About The Author

    Dr. Syra Hanif M.D.

    Board Certified Primary Care Physician

Dr. Syra Hanif is a board-certified Primary Care Physician (PCP) dedicated to providing compassionate, patient-centered healthcare.

Read More