Peanut allergy in children By Sandra Hood, Dietitian What Is the difference between food allergy and food intolerance?
Prevalence of food allergy and intolerance
A f o o d allergy is a reaction to an otherwise harmless food or food component t h a t involves the body's immune system. A reaction occurs w h e n the body's immune system responds abnormally t o t h e protein or proteins in that particular food. The body reacts by flooding the system with histamine and other chemicals to fight off what is perceived as an invader in the body, as it w o u l d t o an infection by a virus or bacteria.
Figures show that more children are suffering with food allergies and food intolerances than ever before. In the UK as many as 5-8% of children suffer with food allergy, around 15-20% of children suffer with eczema ( 3 % of which may have a significant problem with food), asthma affects some 14% of all children, an increase of over 300% since the 1970's and hyperactivity is increasing and ear infections are common. However the incidence of food allergy and intolerance has not been investigated in vegan children and it would be interesting to know whether the incidence is lower than in omnivorous children.
Food allergy can be severe and symptoms may occur rapidly - vomiting, diarrhoea, urticaria (skin eruption), angioedema (swelling of t h e face, throat or skin), stomach pain, exacerbation of atopic eczema, asthma, and anaphylactic shock that may involve the respiratory and cardiovascular systems and result in death. Peanuts and tree nuts are the most likely foods to cause the extreme form of severe food allergy, analphylactix. Reactions to food or f o o d ingredients that do not involve the immune system are called food intolerance or sensitivity. Conditions relating t o f o o d intolerance such as IBS (irritable bowel syndrome), eczema and migraine affect some 4 5 % of the UK. Coeliac disease, an intolerance to gluten, is estimated at around 1 in 1000 but it seems likely that t h e condition is underdiagnosed and this figure considerably underestimated. The incidence of coeliac disease in children has declined, probably due t o changes in weaning practices, with avoidance of exposure to gluten before four months of age. (see "Being a gluten-free vegan" in 'The Vegan' A u t u m n 1991) Intolerances are not life threatening but can cause long term damage and a lot of distress.
What causes food allergy or Intolerance? It has been suggested that the increase in allergies and intolerances may be environmental, or due to our more sterile lifestyles or maybe caused by the poor W e s t e r n diet composed of meat and milk. Other schools of thought are that t h e majority of people do not eat enough fruits and vegetables which undoubtedly build up our immune system and protect against many diseases. Environmental pollutants, genetics and diet may all play a part. Allergies and intolerances can be inherited although this does not mean that parents w h o are allergic will pass it on, but it is more likely. It is not the specific allergy that is passed on but the susceptibility t o have allergic reactions. Adverse reactions to f o o d can occur at any age - about 2 0 % of adults in the UK believe they are allergic to particular foods but the true prevalence is around 1%. Allergy is more likely in infants than adults because the Gl (gastro-intestinal) tract is immature and the immune system is not fully developed.
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The V e g a n , W i n t e r
2001
Understandably many vegan parents have expressed their concern regarding allergenic foods, particularly peanuts and their suitability for young children, especially as the prevalence of peanut allergy is increasing. The symptoms of peanut allergy do vary, from mild to potentially life threatening and therefore the allergy warrants extra care. However it should be remembered that allergic reactions are nearly twice as likely to occur from milk and eggs than from peanuts. In the UK around 6 % of children under the age of 5 suffer with cow's milk intolerance causing nausea, vomiting, diarrhoea, asthma and eczema. It has been suggested that children exposed to cows' milk early in life may have a higher risk of developing diabetes. Allergy to eggs is relatively common in infancy and can cause a severe reaction with 20% of these children suffering allergic reactions into adulthood. Eggs and dairy foods are well known causes of allergic ailments in the very young but in the vast majority of cases a child is highly unlikely to experience anaphylaxis.
How common is peanut allergy? It is believed to affect around 1% of the pre-school children in the UK but the true prevalence is unknown. Peanuts are the most likely food to provoke fatal anaphylaxis in children and adults but many other foods including cows milk, eggs, fish, shellfish, seeds and tree nuts can cause this. The age at which peanut allergy occurs appears to be decreasing, often presenting before a child is 2 years old. Peanut allergy is usually a life-long condition but there may be changes in symptoms and severity and in a small number of cases, it does disappear. The peanut (Arachis hypogaea) is a legume and although it is related to peas, beans and lentils, the majority of peanut allergic patients can eat other legumes without adverse affects. It is more common for people with peanut allergy to react to tree nuts, the most common being brazil, almond, walnut.
pecan and hazel. Therefore it is recommended that a peanut allergic child avoids all nuts. Peanuts have many beneficial qualities and are rich in nutrients, containing the antioxidant vitamin E, folic acid, phytochemicals, fibre, vitamins, minerals and plant protein which may all contribute to heart disease protection. Peanuts are high in mono and polyunsaturated fat which is known to reduce cholesterol raised cholesterol levels are linked to heart disease. Peanuts are a very useful addition to the vegan diet and need not be avoided in children unless there is a history of allergy in the family. In those who are allergic to peanuts, the symptoms are severe and occur rapidly - vomiting, diarrhoea, urticaria (itchy skin), angioedema (swelling of the face, throat or skin), stomach pain, exacerbation of atopic eczema, asthma, and anaphylactic shock. If untreated, anaphylactic shock can result in death due to the obstruction of the upper or lower airway or low blood pressure and heart failure. This happens within minutes to hours of eating peanuts. Owing to the seriousness of this, it is not surprising that vegan parents are concerned as to whether they should expose their children to peanuts.
Is my child at risk of peanut allergy? The evidence is that allergic reactions to peanuts occur in children whose parents or siblings already suffer from allergies including asthma, eczema and react to inhaled allergens (an allergen is a substance that can produce an immune response) such as dust mites and also react to specific foods.
Why do peanuts cause such a severe reaction? W e do not know. The main allergens appear to be glycoproteins - the proteins in peanuts. In severe cases, an immune response can lead to the lining of the lungs to swell, obstructing the upper or lower airway making breathing difficult or impossible. Peanut protein has been shown to be undetectable in refined peanut oil and no adverse reactions have been shown in peanut sensitive people exposed to refined peanut oil.
Should peanuts be avoided by pregnant or breastfeeding women? Only if there is a history of allergies. It is suggested that women who are atopic (suffer from asthma, eczema or food allergy) or where the father or any sibling has atopic disease, may wish to avoid peanuts in their diet in order to reduce the risk of their children developing peanut allergy but this is just precautionary as there has not been any conclusive evidence. Any child that is born to an atopic family is encouraged to be breast fed, preferably
exclusively for the first four to six months as exclusive breastfeeding offers protection against the development of allergies. Breast milk contains proteins which block the entry of whole proteins from the baby's immature gut into the bloodstream until the gut is naturally unable to absorb such molecules. It also contains immune factors which helps the baby's immature system to mature more rapidly. Despite the protection of breast milk, allergic disease can still occur but this is usually in the case of the highly sensitive infant where there is a strong family history of allergy.
When can peanuts be introduced to children? In families where there is a history of allergy, eczema and asthma, peanuts and peanut products should be delayed until the child is at least three years of age. All other nuts are suitable. However, if a child is allergic to peanuts, it is recommended that all tree nuts be avoided until the child is at least three years of age. All other children may have peanuts and tree nuts of a suitable texture, such as smooth nut butter, from the age of six months or when weaned, but not before the age of four months. There is no doubt that parents can pass on a susceptibility to disease including allergies and intolerances. However, if children develop strong and fast immune systems this will protect and prevent many of the diseases afflicting the western world. There is no doubt that the vegan diet, rich in fruits, nuts, pulses and vegetables, low in saturated fat and high in fibre is highly protective and provides our children with the ability to live long and healthy lives.
Summary • Peanuts are the most likely food to cause the extreme form of severe food allergy, anaphylactic shock, and tends to be a life-long condition • Allergic reactions are nearly twice as likely to occur from milk and eggs than from peanuts • Exclusive breast feeding up to 6 months of age offers protection against the development of allergies • Peanuts should be avoided by pregnant or breastfeeding women if there is a history of allergies • A peanut allergic child should also avoid tree nuts • Peanuts are rich in nutrients which may contribute to protection against heart disease • A vegan diet with its high levels of antioxidant vitamins, particularly fruits and vegetables, protects against many diseases