The Suffolk Nutrition Clinic

As many as one in five children are likely to react to a food in their diet. However, this statistic is believed to increase significantly for children with behavioural problems with as many as one in three children reacting adversely to something they are eating.

Food allergies can cause a diverse range of symptoms including fatigue, slowed thought processes, irritability, agitation, aggressive behaviour, nervousness, anxiety, depression,  hyperactivity and learning disabilities. Understanding which foods may be adversely affecting your child’s health can be difficult as both food additives and staple food items can be culprits.

Food Allergy, or Food intolerance?

These days people use the terms food allergy, food intolerance and food sensitivity almost interchangeably. So, what is the difference between these terms?

The classic definition of an allergy is when the immune system produces a marker known as an antibody called IgE (immunoglobulin type E). As the offending food, (called an allergen), enters the blood stream and meets its IgE marker it triggers the release of chemicals including histamine that cause the classic symptoms of allergy - skin rashes, hay fever, rhinitis, sinusitis, asthma, eczema, swelling in the face or throat and anaphylaxis. These 'IgE-mediated' reactions are immediate and sometimes severe with life-threatening consequences. If your child has this type of allergy, you probably already know about it and are strictly keeping your child away from the offending food.

Intolerances on the other hand are delayed reactions and are not life threatening. They are marked by a different antibody called IgG (immunoglobulin type G). These antibodies can be measured using a finger prick blood test that I use in the clinic. Reactions caused by IgG antibodies include eczema, asthma, recurrent ear infections, digestive problems (including bloating, constipation and diarrhoea), and some behavioural or learning problems.

An alternative method of identifying food allergies is an elimination and challenge diet. This involves removing any likely culprits from your child's diet for a period of time (from two weeks to three months may be required) and noting any changes in behaviour, mental and physical symptoms. Then reintroduce the foods in a controlled way, again monitoring closely for any changes in behaviour, mental and physical symptoms. This method has many shortcomings because the range of foods that a child can react to is so broad.

Foods that invoke an IgE type immediate and severe reaction most likely need to be avoided for life. In contrast, delayed IgG allergies may not be long-term. By identifying the foods that your child is allergic to, strictly avoiding them for three to six months and improving digestive health, your child may lose their allergy to them. In some cases, an IgG allergy reaction is for life, however. (If you'd like to find out more read Hidden Food Allergies, by Patrick Holford and Dr James Braly).

What causes a child to become sensitive to a particular food?

Digestive problems are often the underlying factor that leads to the development of a delayed food intolerance. If a child has an excessively 'leaky' digestive tract this means that undigested proteins can enter the bloodstream and the body mistakenly identifies them as a foreign body and reacts. So identifying and avoiding what your child is reacting to is only one half of the equation; improving the health of their digestive tract is equally important to achieve a return to optimum health.