Food Intolerance

Children may develop physical symptoms and (although this is more controversial) behaviour problems because of food they have eaten. The foods that cause the trouble may be natural, like wheat, eggs, milk or chocolate, or they may be artificial substances added to food for colouring or as preservatives.

The child’s reaction may be caused in a number of different ways. The food may be infected or contain chemicals that are poisonous (toxic) to the child: bacteria and viruses may cause food poisoning in this way, but some foods may be chemically toxic to sensitive children, even though they are not infected. The child may be lacking in an enzyme to deal with the food in question, so that toxic substances build up and harm him, or he may have an allergy.

Normally, the immune system of the body reacts to substances or organisms it thinks are attacking it, such as bacteria, by developing antibodies. The antibodies are formed the first time the substance attacks the body, and the person is then sensitised. When the substance attacks the body again, the antibodies are released again. Usually the result of the antibody release is a healthy one, mobilising the body’s defences effectively against attack. However, in predisposed children, the immune system of the body may also react by producing allergic symptoms such as asthma, eczema, hay fever, diarrhoea, and, possibly, behaviour problems, like hyperactivity.

Doctors use the term ‘allergy’ in an exact sense to describe the body’s responses when the immune system is involved, but many people use the term much more loosely: for example, they may say, ‘I think I am allergic to my boss.’ It is important to remember that allergy is only one of the ways in which the body can react unhealthily to substances in the environment.

Food intolerance can run in families, so if your husband or you or a close relative suffers from eczema, asthma, rhinitis (runny nose and eyes) or other symptoms of sensitivity there is a greater chance that your child may also suffer.

Some preventive action is possible in the case of food allergy or sensitivity. To show symptoms a baby must first have been exposed to the foreign protein antigen causing the problem – once he has encountered the antigen and begins to react he is said to be ‘sensitised’. Some specialists suspect this can happen before birth if an allergic mother-to-be eats something which causes her to react. Her raised antibody level enters the baby’s circulation and the baby could theoretically be born with a ready-made sensitivity to that food. Although there is no hard factual evidence to support this, there is some anecdotal evidence, and it is worth while for women with allergies to have their problem identified and controlled as effectively as possible before and during pregnancy and then follow a safe diet in pregnancy to avoid an allergic attack. Naturally this applies only to food allergy and not to inhaled substances such as pollen.

Cow’s milk is one cause of food allergy. The importance of this lies in the nutritional role of milk in the diet, especially of young children. The immature immune system of new babies is particularly sensitive and may react to the foreign protein in cow’s milk. If there is a family history of allergy, mothers are particularly advised to breastfeed exclusively for the first four to six months, not to take in too much milk or milk products themselves, and if possible make sure their baby does not have any formula feeds at all – one bottle is quite enough to sensitise a baby. When breastfeeding is not possible a soya or modern specially modified formula feed may be advised, but soya can also affect some children, as can goat’s milk which is not suitable for babies in any case. Your doctor or paediatrician should advise. It may be that you should not give any fresh cow’s milk or milk products such as cheese and yoghurt or egg until your child is a year old but continue the formula feed.

Introduce a small quantity of these foods (a teaspoon or two) for the first day or two. Stop if there is any reaction. Symptoms vary but common signs are skin rashes, miserable behaviour, failure to thrive or gain weight and occasionally colic. Remember, however, that babies can get these symptoms from a number of other causes, and if symptoms have started suddenly after months of successful feeding with foods based on cow’s milk, then it is unlikely that cow’s milk protein intolerance is the cause. Remember too that if you reduce your baby’s milk intake, the nutrients in milk like calcium, vitamins, protein and calories must be replaced in the diet to avoid affecting growth.

How Can You Tell if Food Intolerance Is Your Child’s Problem?

‘My daughter was fine while breastfed but when I started solids she began getting a rash around her mouth and horrible nappies. I had a friend with a child that was milk allergic and wondered if this could be the same problem with the milk content in the solids causing a reaction. Sure enough, after three milk-free days the rash and the diarrhoea disappeared. I tested by giving her a small amount of cheese mixed with potato and by the end of the meal her skin began to look red around the mouth and within an hour _the rash was quite noticeable.’

The only sure test of any food intolerance is elimination and challenge. This means eliminating, or cutting out, the suspect food from the diet and then, once symptoms have disappeared, challenging by reintroducing a small amount again with the symptoms reappearing. If symptoms do not disappear or reduce significantly within three to five days of completely cutting out the food, you can conclude this is unlikely to be the problem. If they do disappear and return with reintroduction of the food it seems likely that this is the cause. When this is done under the supervision of a specialist, it will be strictly controlled to make sure the suspect food really is being eliminated and not taken in other forms, and that the child’s diet remains nutritionally balanced. However, more than one food may be the cause, and sorting this out is definitely a job for an expert.

Parents often try eliminating foods from their child’s diet without any medical supervision in the hope that it may help a physical or behavioural problem. There are potential hazards with do-it-yourself testing and children should not be put on elimination diets without expert supervision. There are possible dangers in reintroducing foods to a child who is highly allergic, and it is also sometimes a difficult task to pinpoint exactly what is causing a reaction because it is often a combination of quite unrelated foods. Parents should seek medical advice and the correct diagnosis of symptoms. If they are to test their child safely for food intolerance, they must be careful to bear in mind the points made below: