EVERYDAY FOODS CAN BE ALLERGENS
Karen Wright, the Paediatric Dietitian from The Food Clinic, shed light on the so-called ‘Big 8’ most common food allergens. This chart explains what they are, where they are found, and other important information.
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Food Allergen
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Foods to Avoid
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Good to Know
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Cow’s milk
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All mammalian milk drinks, milk powder, butter, cream, yoghurt, also used as a glaze, in soups, sauces and in many desserts, manufactured foods, processed meat products and baked items such as cakes and biscuits
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The proteins in goat’s, sheep and other animal milks are very similar to cow’s milk and should also be avoided
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Soy
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Bean curd, edamame beans, miso paste, soya flour, tofu, soya sauce and as an additive in many manufactured foods such as bread, desserts, ice cream, meat products, sauces and vegetarian products
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Used extensively in processed and manufactured food products
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Wheat
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Foods containing flour, baking powder, batter, biscuits, breads, breadcrumbs, cakes, couscous, pasta, pastry, sauces, soups, fried foods dusted with flour and in many processed and convenience foods
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Some other cereals such as rye, barley and oats can also trigger allergic reactions. Coeliac Disease should not be confused with wheat allergy.
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Eggs
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In baked goods such as cakes and muffins, meat products, quiche, sauces, pasta, noodles, pancakes, waffles, pastries and foods glazed with egg
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Most people with egg allergy can tolerate some baked products containing egg
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Peanuts
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In biscuits, cakes, curries, porridge, desserts, sauces, confectionery, flours and oils
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Peanuts are actually a legume and grow underground, hence they are also called groundnuts. It is the commonest hidden food to cause an allergic reaction at any age. Even a minor exposure can cause a reaction.
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Tree nuts
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In breads, biscuits, crackers, desserts, nut powders and butters, savoury stir-fried dishes, marzipan, nut oils and sauces
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Tree nuts are nuts which grow on trees such as cashew nuts, almonds, hazelnuts, pistachios, walnuts, pine nuts, macadamia nuts and pecans
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Fish
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In main courses, sauces, relishes, dressings, on some pizzas, stock cubes and in Worcestershire sauce
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There are many varieties of fish, and it is possible to be allergic to one group but not to another
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Shellfish
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Dishes containing crab, lobster, shrimp, prawns, scampi, abalone and scallops
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Some shellfish allergies, especially those that develop later in life, can be mild, only causing oral symptoms. Others, developing in the first years of life, may be serious.
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Please note that the list above is not exhaustive and expert medical and dietetic advice should always be followed.
WHAT HAPPENS DURING AN ALLERGIC REACTION
Any allergic reaction is the immune system’s response to a food the body mistakenly believes is harmful. The symptoms are caused by the sudden release of chemical substances, including histamine, from blood cells and tissues where they are stored. This mechanism is so sensitive that even minute quantities of the food allergen can cause a reaction.
Allergic reactions can be immediate with symptoms occurring within minutes to 2 hours after ingestion of the allergen. Symptoms may include rashes (known as hives or urticaria) anywhere on the body, or a tingling or itchy feeling in the mouth.
More serious symptoms may include swelling of the face, throat and/or mouth; difficulty breathing, wheezing; an asthma attack; tummy pain, nausea and vomiting.
The most serious form of allergy is called anaphylaxis. In extreme cases there could be a dramatic fall in blood pressure (anaphylactic shock). The person may become weak and floppy and may have a sense of something terrible happening. This may lead to collapse and unconsciousness. On rare occasions, death can occur.
Allergic reactions can also be delayed, since they also involve parts of the immune system that take much longer to respond and are therefore more difficult to diagnose. Trying to determine if the cause is due to a food requires the help of an experienced doctor. In young infants, delayed allergies may cause symptoms such as chronic eczema, reflux, poor growth, vomiting and diarrhea or even constipation. Since these are common childhood conditions, allergy is not always the cause and expert help should be sought in making a diagnosis.
THE TREATMENT IS MANAGEMENT
If you know or suspect you are allergic to any food, you should see your GP as soon as possible. He or she will then refer you to a specialist allergy clinic. The allergist will use a detailed history of your symptoms, what and how much you ate and other events that occurred at the time of the reaction, aided by results of skin prick tests and blood tests, to help reach a diagnosis. Where reactions are delayed, diagnosis is more tricky as there are no reliable tests. Diagnosis is usually made with an experienced allergy doctor and dietitian, using a food elimination diet. If symptoms disappear when foods are excluded, a reintroduction diet is used, and if symptoms then return on reintroduction, a diagnosis can be reached. These diets should not be undertaken without medical support as they are restrictive, particularly for infants and children.
Once a food allergy has been confirmed, a registered dietitian can help you avoid the food or foods to which you are allergic, recommend suitable alternatives and ensure the diet is nutritionally balanced. This is particularly important for children to ensure they grow and develop well. Understanding how to read food labels correctly is vital in the management of food allergies.
AVOIDANCE IS KEY
“If a severe allergy has been identified, it is important that exposure to even tiny amounts of the trigger food are avoided,” said Karen. “Very occasionally, reactions can occur even when the person has had skin contact with the offending food. For example, some peanut allergic people may suffer a severe reaction just through being kissed by someone who has eaten peanuts.”
Similarly, a fish allergy sufferer can experience an adverse reaction simply by entering a kitchen where fish is being cooked.
Care should be taken at all times when preparing food for allergy sufferers. Separate cooking utensils should be used, and all cooking surfaces carefully washed to avoid cross-contamination. High-risk situations where cross-contamination can occur include barbeques, buffets, self-service salad bars and deli counters.
ALLERGY FIRST AID
If a severe food allergy is suspected, you will be given an emergency treatment plan by your allergist, which may include antihistamines and adrenaline (also known as epinephrine) that can be self-administered in the form of an EpiPen® injector. Allergy sufferers should carry their injectors with them at all times, so it is available to use when required and know when and how to use it.
ALLERGIES ON THE RISE
The last four decades have seen a dramatic rise in allergic diseases such as asthma, eczema, hay fever and food allergies.
“We are still not entirely sure why there has been such a rapid increase in allergies. Environment and genetics certainly play a part. The increasing cleanliness of the world in which we live may be a contributing factor leaving our immune systems under-stimulated,” said Karen. “With fewer bacteria and viruses to fight, the body mistakenly reacts to harmless things such as pollen or foods. We know that children who grow up on farms are less likely to have allergic diseases and recently a research paper found that domestic dog exposure at birth reduces the incidence of atopic dermatitis allergy (eczema).”
Though it may not be clear why food allergies are on the rise, one thing is for sure – there is currently no ‘cure’ (although new treatments are being researched and are emerging). Avoidance of the triggers, reading food labels and understanding what you are eating are still of paramount importance. It is not overly dramatic to say that it can even be a matter of life and death.
With thanks to our contributor:
Karen Wright
Paediatric Dietitian
The Food Clinic
