Adverse food reactions are abnormal reactions of the body to food either via ingestion, contact or inhalation of food substances. It is divided into two types: Food allergy and Food intolerance. It is important to differentiate between the two types because their dietary and medical interventions vary. Here are some simple ways of determining whether you are having a food allergy or food intolerance.
Food allergy is due to the abnormal reaction of the immune system against substances or proteins in foods, referred to as allergens. Common food allergens are usually found in the “Big 8” which are: milk, eggs, peanuts, tree nuts, fish, crustacean shellfish, wheat and soy. Allergies usually results to abnormal physical response towards food either by ingestion, contact or inhalation, such as itchiness, rashes, anaphylaxis or difficulty of breathing related to an allergic reaction, swelling, redness, diarrhea. Symptoms occur within minutes to 2 hours (immediate reaction) up to 48 hours (delayed reaction) after exposure to the food. Examples of food allergies are:
1. Oral-allergy syndrome (OAS) - an allergic reaction that is confined to the lips, mouth and throat. OAS most commonly occurs in people with asthma or hay fever from tree pollen who eat fresh (raw) fruits or vegetables.
2. Celiac disease – an autoimmune disease that occurs in genetically predisposed people where the ingestion of gluten leads to damage in the small intestine.
3. Allergic contact dermatitis - a red, itchy rash caused by direct contact with any substance or food or an allergic reaction to it.
Management includes avoidance of the trigger food item, antihistamines, epinephrine for anaphylaxis or difficulty in breathing, corticosteroids for severe reactions and immunotherapy.
Food intolerance, on the other hand, is non-immune mediated and is due to a deficient enzyme in the digestive system (lactase deficiency) or a chemical substance in the food such as carbohydrates like lactose, galactose, glucose and fructose, food additives or toxins which may irritate the digestive system. Symptoms include abdominal pain, vomiting, diarrhea, asthma, rashes, migraines, headaches, fatigue and some behavioral problems, which occurs within 48 hours after exposure to the food. Symptoms may vary in severity or type depending on the amount of food ingested. Examples of food intolerance are:
1. Lactose intolerance - a digestive disorder caused by the inability to digest lactose, the main carbohydrate in dairy products. It can cause various symptoms, including bloating, diarrhea and abdominal cramps. People with lactose intolerance don't make enough of the enzyme lactase, which is needed to digest lactose.
2. Fructose intolerance - a disorder in which a person lacks the protein needed to break down fructose.
3. Galactosemia – refers to a group of inherited disorders that impair the body's ability to process and produce energy from a sugar called galactose. When people with galactosemia ingest foods or liquids containing galactose, undigested sugars build up in the blood.
4. Food poisoning - an illness caused by eating contaminated food. In most cases of food poisoning, the food is contaminated by bacteria, such as salmonella or Escherichia coli (E. Coli), or a virus, such as the norovirus.
Management of intolerance includes identifying the trigger food, identifying underlying conditions, investigating for possible food poisoning, decreasing amount of food ingested to lessen symptoms and using alternative or modified food to lessen food intolerance.
If you feel like you have a food allergy or food intolerance, consult your doctor so you may undergo diagnostic tests to confirm your condition which will help determine what kind of dietary modification is right for you. Consult a Registered Nutritionist-Dietitian for specific dietary interventions for alternative foods and amount recommendations to ensure that you are getting adequate nutrients from your diet and to prevent future adverse food reactions.
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References:
Boyce, J. A., Assa'ad, A., Burks, A. W., Jones, S. M., Sampson, H. A., Wood, R. A., ... & Schwaninger, J. M. (2011). Guidelines for the diagnosis and management of food allergy in the United States: summary of the NIAID-sponsored expert panel report. Journal of the American Academy of Dermatology, 64(1), 175-192.
Jamorabo-Ruiz, A., Serrano-Claudio, V. & Exevea-de Castro, Esperanza (2011). Medical Nutrition Therapy for Filipinos, 6th ed. Manila: Merriam & Webster Bookstore, Inc.
