Food Allergy Vs Food Intolerance: What's The Difference?

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Food allergies and food intolerances are both adverse reactions to food, but they differ significantly in their causes, symptoms, and severity. Understanding these differences is crucial for proper diagnosis and management. Dr Akash Shah, Consultant Pathologist, Neuberg Diagnostics will help you to get a better picture about the difference between food allergy and food intolerance.

Food Allergy

A food allergy involves the immune system. When someone with a food allergy consumes a particular food, their immune system mistakenly identifies it as harmful and triggers an allergic reaction. This reaction involves the production of immunoglobulin E (IgE) antibodies, which cause the release of histamines and other chemicals in the body. These chemicals lead to symptoms that can range from mild to severe and include hives, swelling, difficulty breathing, and anaphylaxis—a potentially life-threatening condition requiring immediate medical attention.

Common food allergens include peanuts, tree nuts, shellfish, fish, milk, eggs, soy, and wheat. The onset of symptoms usually occurs within minutes to a couple of hours after consuming the allergenic food. Even trace amounts of the allergen can provoke a reaction, making strict avoidance and careful management essential for individuals with food allergies.

Food Intolerance

Food intolerance, on the other hand, does not involve the immune system. Instead, it occurs when the digestive system is unable to properly break down certain foods. This can be due to enzyme deficiencies, such as lactase deficiency in lactose intolerance, or other gastrointestinal sensitivities.

Symptoms of food intolerance are generally less severe than those of food allergies and typically involve the digestive system. They include bloating, gas, diarrhea, stomach pain, and cramping. These symptoms can take longer to develop, often appearing several hours after eating the offending food. Unlike food allergies, food intolerances are dose-dependent, meaning that a person might tolerate small amounts of the food without experiencing symptoms but will react to larger quantities.

Key Differences

The primary difference between food allergy and food intolerance lies in the involvement of the immune system. Food allergies trigger an immune response, which can be life-threatening, whereas food intolerances result from digestive issues and are generally not life-threatening. The speed and type of symptoms also vary: allergic reactions are typically swift and can affect multiple body systems, while intolerance reactions are slower and usually confined to digestive discomfort.

Diagnosis and Management

Diagnosing a food allergy typically involves a combination of patient history, skin prick tests, blood tests measuring IgE antibodies, and sometimes oral food challenges under medical supervision. Food intolerance diagnosis often involves elimination diets and food diaries to identify the offending food, as well as breath tests for conditions like lactose intolerance.

Management of food allergies requires strict avoidance of the allergen and readiness to treat accidental exposures, often with antihistamines and epinephrine auto-injectors. Managing food intolerances usually involves limiting or avoiding the problem of food and using supplements like lactase for lactose intolerance.

Understanding whether one has a food allergy or intolerance is crucial for effective management and avoiding serious health consequences. Consulting healthcare professionals for accurate diagnosis and personalized advice is always recommended.