Food Allergy

Food allergy and food intolerances are phrases we hear a lot these days. More and more people are cutting out foods to try to relieve problems like irritable bowel syndrome and skin problems. However, there is a lot of confusion about allergies and intolerances as well as how often a particular food really is the cause of the problem.

What is a Food Allergy?

A food allergy is a reaction to a food that happens through your immune system. Your immune system is made up of lots of cells and tissues whose job is to help keep you well and fight infections.One part of your immune system is an antibody called IgE. IgE helps your body to target very specific substances that come into your body and ‘attack’ them to help to get rid of them. When someone has a food allergy, their IgE has decided to target a specific food instead of a harmful substance. Their IgE might target the proteins found in peanuts, cow’s milk, soya or fish.

When someone who has an allergy eats a food they are allergic to, it causes an immune reaction in their body. The reaction can be different from person to person. Some people will have a rash or itching, some might find that their mouth and lips swell and, in severe cases, breathing can become difficult.

What tests can check for a food allergy?

Your GP can arrange a blood test or skin prick test to check for a specific IgE to a food that you think you have reacted to. Not all food allergies are caused by IgE so you may need so it is a good idea to speak to a dietitian or doctor who is experienced in dealing with food allergies, as a good history of the reaction and symptoms is important in deciding which IgEs to test for or which foods to focus on. Remember: it is never a good idea to just ‘test for everything’. You will also need to rule out anything else that might be causing a reaction – you would be surprised how often someone was sure they had a food allergy only to find out that their problem was caused by something else!

Managing a Food Allergy

If you have been diagnosed with a food allergy, then you need to avoid the food that is causing the problem. For many foods this can be straightforward but if your reaction is to something like gluten, wheat or dairy or if you have several allergies, then you need to see a qualified dietitian for advice as you may be missing out on key nutrients. Children in particular need to see a qualified paediatric dietitian when they are diagnosed with a food allergy.

What tests are not recommended to test for food allergies or intolerances?

There are lots of tests out there that claim to test for allergies or intolerances. Experts have reviewed other tests (such as hair analysis, Vega testing, IgG testing etc.) and have found that they have no role in testing for food allergies.

Are my symptoms caused by a food allergy?

This is a really important question! Almost everyone assumes that any bowel problem is a food allergy or intolerance and starts cutting out wheat or dairy. People often look to food allergies for problems like eczema and colic. Food allergy can certainly be a cause for some of these problems, but in many cases there is something else going on. 79% of Irish people do not eat enough fibre. Not eating enough fibre can lead to irregular bowel movements, bloating, lack of energy and so on.  So before you start testing for allergies, do speak to your GP or a qualified dietitian who will be able to check your diet and advise you on whether or not you need to look at food allergy testing. To find a qualified Dietitian (a member of the INDI) go to www.indi.ie or www.sedi.ie . For more information about allergies go to www.ifan.ie