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Fact Files : Food Allergies and Intolerances
Some people are sensitive to particular foods and may suffer from food allergies or intolerances. Understanding the difference between food allergies and food intolerances is an important starting point because the approach to dealing with them is quite different.
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Food Allergy |
Food Intolerance |
| Inheritance
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Can be inherited
Children whom have no parents with allergy have a 20% risk of having one allergy disorder. If one parent has an allergy disorder the risk increases to ~ 40%. If both parents have allergy disorders then the risk increases to
60 - 70 %. |
Possibly inherited
Some people are born with a sensitive constitution and react more readily to food components than others. It must be noted however, environmental triggers such as a viral infection, sudden dietary change or severe food or medication reaction can bring on symptoms at any age by altering the way the body reacts to foods. Also physiological triggers such as hormonal changes during child-bearing years or menopause can often increase sensitivity. |
| Immune System Involvement
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Reaction involves the immune system |
Reactions do not involve the immune system though rather involves the stimulation of nerve endings in tissues by a chemical component. |
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Food Allergy |
Food Intolerance |
| Triggers |
Usually triggered by food proteins
i.e.
Eggs
Peanuts
Milk
Other nuts
Sesame
Gluten
Fish
Grains such as rye, what and oats
Soy
Molluscs such as oysters, mussels, clam, squid and octopus
Crustaceans such as lobster, prawns, crab and shrimp
Fruit, berries, tomato, cucumber, white potato or mustard
Food additives such as benzoates, salicylates, MSG and sulphite derivatives |
Usually triggered by food chemicals and food additives i.e.
Preservatives
Artificial colours and flavours
Salicylates – found abundantly in fruits and vegetables, herbs & spices, tea & coffee, beer and wines
Amines – found in some fruit & vegetables, cheese, chocolate, wine & beer, aged meat & fish products
Naturally occurring glutamates found in stock cubes, meat & yeast extracts, tomato, cheese and pure MSG
Histamine containing and histamine releasing foods |
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Food Allergy |
Food Intolerance |
Diagnosis & Reactions |
Can be detected by skin prick and blood tests (RAST) due to IgE antibody-mediated response
Generally seen in children and usually resolve by school age/adolescence
Occasionally occur in adult life
Reaction time of seconds to four hours.
Reactions can be severe and life-threatening – anaphylaxis
Tiny amounts of irritant can be enough to provoke a severe reaction
Immunological sensitisation occurs |
Can be hard to identify irritants as cannot be diagnosed by skin prick or blood tests
Can occur at any age
Reactions are individual and vary person to person.
Effects are dose related. May be cumulative over days from eating a range of foods
Intolerances are idiosyncratic.
Immunological sensitisation does not occur as in food allergies. |
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Food Allergy |
Food Intolerance |
Treatment |
Treatment involves avoidance of all traces of problem foods |
Treatment involves identifying and reducing intake of offending substances
Not one single"right" diet for people with food intolerances |
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Food Allergy |
Food Intolerance |
Symptoms |
Symptoms include:
Itching, burning and swelling around the mouth
Runny nose
Skin rash (eczema)
Hives (urticaria – skin becomes red and raised)
Diarrhoea, abdominal cramps
Breathing difficulties, including wheezing and asthma
Vomiting, nausea
Sleep disturbances |
Symptoms include but are not limited to:
Nervousness, tremor
Breathing problems
Sweating
Heart palpitations
Headache
Diarrhoea, constipation
Vomiting, nausea
Burning sensation of the skin
Tightness across the face and chest
Rapid breathing
Weight gain or loss
Abdominal pain
Bloating
Drowsiness, lethargy
Disturbed sleep patterns
Skin rash
Reflux Symptoms can be isolated or occur in combination. |
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Food Allergy |
Food Intolerance |
Body parts affected |
Eyes – itching, watering
Nose – stuffiness, sneezing
Mouth/lips – itching, swelling
Throat – swelling
Digestive system – stomach pain. Vomiting, diarrhoea
Skin – rashes, such as hives or atopic dermatitis
Lungs – asthma, more common in children than adults
Central nervous system – headache, irritability, fatigue, convulsions |
Digestive system – nausea, stomach pain, vomiting, diarrhoea
Skin – eczema, rash, itching
Eyes – itching, watering
Nose – stuffiness, sneezing
Mouth/lips – itching, swelling
Throat – swelling
Digestive system – stomach pain. Vomiting, diarrhoea
Skin – rashes, such as hives or atopic dermatitis
Lungs – asthma, more common in children than adults
Central nervous system – headache, irritability, fatigue, convulsions |
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