Member - Academy Of Nutrition & Dietetics. USA.
Allergy and Intolerance Nutrition
We have often heard people commenting on allergy towards certain foods. The prevalence of food allergy has doubled over the last two decades. But people commonly confuse adverse reaction to a food with food allergy. Until properly diagnosed adverse food reaction should not be interchanged with food allergy.
Immunologic Basics
Definition
Let us get familiarized with few important terms. Food intolerance is an adverse reaction to food caused by toxic, pharmacologic or nonimmunoglobulin E (IgE) reactions to food or chemical substances in food. Food allergy is an IgE-mediated reaction that occurs when the immune system reacts to a normally harmless food protein the body falsely identifies as harmful. This reaction occurs immediately or within 2 hrs of consumption and is prominent in infants below 2 years of age.
Immune System
The main job of the immune system is to safeguard the body against antigens such as viruses, bacteria, blood cells and tissue cells. When antigens and immune system cells meet face-to-face, antigens are smoothly emptied out of the body. Allergy is different from this as sensitization occurs. Sensitization is a phenomenon where exposure to an antigen or allergen results in the development of hypersensitivity.
Allergic Reactions
Allergic reactions are abnormal reactions of the immune system and represent altered reactivity to an antigen. These types of antigens are called allergens. Common reactions to allergies are diarrhea, bloating, vomiting, itching, nausea and eczema.
Symptoms
Skin and respiratory symptoms are very common during an allergic reaction. Anaphylaxis is an acute, severe and rarely fatal immune response that occurs within a short time following antigen exposure. It can cause nausea, vomiting, chest pain, diarrhea, lowered blood pressure, shock and death. Peanuts and nuts are common causes for death while milk and fish are also said to be close behind.
Risk Factors for the Development of Food Allergy
Getting oneself allergic to certain foods is dependent on heredity, microbial exposure, exposure to a certain food and gastrointestinal permeability. Heredity plays a prominent role in atopic diseases such as hay fever, eczema and asthma. Antigen concentration and environmental factors play a dominating role in the development of food allergies.
Food Intolerances
Gastrointestinal, cutaneous and respiratory disorders are common symptoms of food intolerance. Though common in symptoms the treatment is different from that of food allergy. Food additives such as preservatives, flavour enhancers and colouring agents are said to be common causes of food intolerance. Lactase enzyme deficiency is common worldwide which can be identified with symptoms like abdominal cramping and diarrhea when milk is consumed.
Diagnosis
Diagnosis involves identification of the allergy causing food and confirming immunologic involvement. Avoiding foods without proper diagnosis can lead to nutrient deficiency. Clinical history is the first diagnostic tool. When this is done with a family physician he is aware of your body reaction and history, hence diagnosis becomes much simpler. A 7- to 14- day food and symptom diary is helpful when there is a generic food reaction. Details about the time of food consumption, type of food eaten, quantity consumed and ingredients present in the food come to aid in identifying any health issues. Skin tests, particularly for children with atopic dermatitis, are the best as they are economic and speedy giving you results within 30 minutes.
Food Elimination Diet
Food elimination is an expensive tool used to diagnose chronic symptoms. All forms of the elimination diet must be thoroughly removed from the food consumed. This process will confirm if symptoms improve or resolve with avoidance. If symptoms improve then the food can be surely avoided, if not, then other causes should be analyzed.
Food Challenge
Food challenge is performed once the symptoms have been cured. The patient is challenged with foods and if the response is positive medication must be given to stop the symptoms. A person must not be challenged until the results are conclusive that no reaction to allergen is involved and skin test results are negative.
Treatment
The best and simple treatment for food allergy is to totally avoid the food allergen. But when certain foods are removed from a diet alternative nutrient sources must be consumed. But when multiple foods are omitted simultaneously, supplements are the only way to compensate for the lost nutrients.
Food Allergy in Infancy
Pediatricians often advice against feeding infants with cow’s milk as the cow’s milk protein (CMP) is one of the primary allergens for infants which may result in constipation. The best food for babies is always mother’s milk. When breast-feeding is not possible extensively hydrolysated cow’s milk is preferred to standard cow’s milk. Try to avoid goat’s milk totally as they lack most of the essential nutrients present in mother’s milk and cow’s milk. Sometimes infants are sensitive to breast-feeding as the mother’s diet may contain allergens such as peanuts, eggs and cow’s milk. In such cases, it is best for the mother to eliminate these allergens from the diet until feeding continues.
Diet and Prevention of Allergic Diseases
Breast-feeding has always been recommended for the first 6 months in an infant’s life. If foods other than breast milk are introduced to infants, it may result in food allergies. Hence, breast-feeding with avoidance of allergens by the mother helps to delay allergic diseases in high-risk infants.
We have often heard people commenting on allergy towards certain foods. The prevalence of food allergy has doubled over the last two decades. But people commonly confuse adverse reaction to a food with food allergy. Until properly diagnosed adverse food reaction should not be interchanged with food allergy.
Immunologic Basics
Definition
Let us get familiarized with few important terms. Food intolerance is an adverse reaction to food caused by toxic, pharmacologic or nonimmunoglobulin E (IgE) reactions to food or chemical substances in food. Food allergy is an IgE-mediated reaction that occurs when the immune system reacts to a normally harmless food protein the body falsely identifies as harmful. This reaction occurs immediately or within 2 hrs of consumption and is prominent in infants below 2 years of age.
Immune System
The main job of the immune system is to safeguard the body against antigens such as viruses, bacteria, blood cells and tissue cells. When antigens and immune system cells meet face-to-face, antigens are smoothly emptied out of the body. Allergy is different from this as sensitization occurs. Sensitization is a phenomenon where exposure to an antigen or allergen results in the development of hypersensitivity.
Allergic Reactions
Allergic reactions are abnormal reactions of the immune system and represent altered reactivity to an antigen. These types of antigens are called allergens. Common reactions to allergies are diarrhea, bloating, vomiting, itching, nausea and eczema.
Symptoms
Skin and respiratory symptoms are very common during an allergic reaction. Anaphylaxis is an acute, severe and rarely fatal immune response that occurs within a short time following antigen exposure. It can cause nausea, vomiting, chest pain, diarrhea, lowered blood pressure, shock and death. Peanuts and nuts are common causes for death while milk and fish are also said to be close behind.
Risk Factors for the Development of Food Allergy
Getting oneself allergic to certain foods is dependent on heredity, microbial exposure, exposure to a certain food and gastrointestinal permeability. Heredity plays a prominent role in atopic diseases such as hay fever, eczema and asthma. Antigen concentration and environmental factors play a dominating role in the development of food allergies.
Food Intolerances
Gastrointestinal, cutaneous and respiratory disorders are common symptoms of food intolerance. Though common in symptoms the treatment is different from that of food allergy. Food additives such as preservatives, flavour enhancers and colouring agents are said to be common causes of food intolerance. Lactase enzyme deficiency is common worldwide which can be identified with symptoms like abdominal cramping and diarrhea when milk is consumed.
Diagnosis
Diagnosis involves identification of the allergy causing food and confirming immunologic involvement. Avoiding foods without proper diagnosis can lead to nutrient deficiency. Clinical history is the first diagnostic tool. When this is done with a family physician he is aware of your body reaction and history, hence diagnosis becomes much simpler. A 7- to 14- day food and symptom diary is helpful when there is a generic food reaction. Details about the time of food consumption, type of food eaten, quantity consumed and ingredients present in the food come to aid in identifying any health issues. Skin tests, particularly for children with atopic dermatitis, are the best as they are economic and speedy giving you results within 30 minutes.
Food Elimination Diet
Food elimination is an expensive tool used to diagnose chronic symptoms. All forms of the elimination diet must be thoroughly removed from the food consumed. This process will confirm if symptoms improve or resolve with avoidance. If symptoms improve then the food can be surely avoided, if not, then other causes should be analyzed.
Food Challenge
Food challenge is performed once the symptoms have been cured. The patient is challenged with foods and if the response is positive medication must be given to stop the symptoms. A person must not be challenged until the results are conclusive that no reaction to allergen is involved and skin test results are negative.
Treatment
The best and simple treatment for food allergy is to totally avoid the food allergen. But when certain foods are removed from a diet alternative nutrient sources must be consumed. But when multiple foods are omitted simultaneously, supplements are the only way to compensate for the lost nutrients.
Food Allergy in Infancy
Pediatricians often advice against feeding infants with cow’s milk as the cow’s milk protein (CMP) is one of the primary allergens for infants which may result in constipation. The best food for babies is always mother’s milk. When breast-feeding is not possible extensively hydrolysated cow’s milk is preferred to standard cow’s milk. Try to avoid goat’s milk totally as they lack most of the essential nutrients present in mother’s milk and cow’s milk. Sometimes infants are sensitive to breast-feeding as the mother’s diet may contain allergens such as peanuts, eggs and cow’s milk. In such cases, it is best for the mother to eliminate these allergens from the diet until feeding continues.
Diet and Prevention of Allergic Diseases
Breast-feeding has always been recommended for the first 6 months in an infant’s life. If foods other than breast milk are introduced to infants, it may result in food allergies. Hence, breast-feeding with avoidance of allergens by the mother helps to delay allergic diseases in high-risk infants.