Food is one of life’s basic needs, but for some people, consuming certain types of food can be problematic. Symptoms can range from mild discomfort to life-threatening reactions.

Two common food-related problems are food allergy and food intolerance. While the symptoms of both conditions may be similar, the causes and underlying mechanisms are different.

What is a Food Allergy?

A food allergy is an immune system response to a particular food protein. The body mistakenly identifies the protein as harmful and triggers an immune response.

The immune system produces an antibody called immunoglobulin E (IgE), which binds to mast cells and basophils, causing them to release chemicals, such as histamine, into the bloodstream. These chemicals cause the allergic symptoms, which can range from mild to severe and may include:.

Hives or rash
Swelling of the face, lips, tongue or throat
Shortness of breath
Wheezing or coughing
Stomach pain, nausea or diarrhea
Anaphylaxis

Anaphylaxis is a severe and potentially life-threatening reaction that can cause difficulty breathing, low blood pressure, and loss of consciousness. It requires immediate medical attention.

What is Food Intolerance?

Food intolerance is a digestive system response to certain foods. The body is unable to properly digest or metabolize the food, which leads to symptoms such as:.

Bloating
Gas
Diarrhea or constipation
Nausea
Abdominal pain

Food intolerance is not caused by the immune system and does not involve the same mechanisms as a food allergy. Food intolerances can be caused by:.

Lack of enzymes needed to digest certain foods
Sensitivity to food additives, such as preservatives and artificial colors
Chemical sensitivity, such as to histamine in certain foods

Causes of Food Allergy

The cause of food allergy is not always clear. However, there are certain risk factors that may increase the likelihood of developing a food allergy, including:.

Family history of allergies
Age – food allergies are most common in young children
Having other allergies, such as hay fever or asthma

Common food allergens include:.

Tree nuts
Shellfish
Eggs
Milk
Wheat
Soy
Peanuts
Fish

It’s important to note that food allergies can develop at any age and reactions can vary from mild to severe.

Diagnosing Food Allergy and Intolerance

The first step in diagnosing any food-related issue is to see a doctor or allergist who will ask questions about your symptoms, medical history, and family history of allergies. They may also perform a physical exam and order diagnostic tests.

The diagnosis of food allergy involves blood and skin tests, as well as an elimination diet. In a skin test, small amounts of allergens are placed on the skin, and the reaction is observed.

A blood test measures the levels of IgE antibodies in the bloodstream. An elimination diet involves removing specific foods from the diet and then reintroducing them one at a time to determine which foods trigger an allergic reaction.

Food intolerance can be more difficult to diagnose because symptoms may not appear immediately and may not be consistent. Keeping a food diary and eliminating certain foods can help identify the offending food.

In some cases, a breath test, blood test, or stool analysis may be necessary.

Treatment of Food Allergy and Intolerance

The only treatment for food allergy is avoiding the offending food completely. In mild cases, symptoms may be treated with antihistamines or corticosteroids. In severe cases or anaphylaxis, an injection of epinephrine (adrenaline) is necessary.

People with food allergies should carry an epinephrine auto-injector with them at all times and learn how to use it. They should also wear a medical alert bracelet or necklace.

Treatment for food intolerance depends on the underlying cause. Avoiding the offending food is the primary treatment for lactose intolerance, for example.

Enzyme supplements can be taken to help digest food, and over-the-counter medications can treat symptoms like bloating and gas. Chemical sensitivity is treated by avoiding foods high in histamine or other triggering chemicals.

Preventing Food Allergy and Intolerance

There is no known way to prevent food allergy or intolerance completely, but certain strategies may help reduce the risk:.

Delay introducing highly allergenic foods to infants until 6 months or older
Avoiding overly restrictive diets during pregnancy and breastfeeding
Reading food labels carefully and watching for hidden allergens
Avoiding cross-contamination in food preparation, such as using separate utensils and cookware for allergenic foods

Conclusion

While food allergy and food intolerance may present similar symptoms, the underlying causes are different.

A food allergy involves the immune system and can cause severe reactions, while food intolerance is a digestive system response and produces milder symptoms. Diagnosing and treating these conditions requires the attention of a medical professional. However, with careful management and avoidance of offending foods, people with food allergies and intolerances can lead healthy and fulfilling lives.