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Allergy or Intolerance?

Posted by Christine Innes APD on 30 July 2014
Allergy or Intolerance?

Do you have food intolerance or food allergy?

Food Allergy

True food allergy is fortunately not too common. Food allergy occurs when the immune system reacts to a protein in a food. Food allergy usually starts in childhood and the reaction is immediate, often severe and can be life threatening. An allergic reaction can occur when exposed to even a small amount of the problem food protein or ‘allergen’. Common allergens are egg, milk, wheat, nuts and shellfish or fish. Some food allergies such as milk or egg may disappear as a child gets older while others such as nut, shellfish or fish may extend into adult life. The first step in diagnosing a food allergy is to see your GP who may refer you to a specialist doctor for testing. Once a diagnosis is made an Accredited Practising Dietitian can help construct a safe and nutritious diet, which will involve total exclusion of the food allergen and an adrenalin pen is carried for emergency treatment. Many people refer to self-diagnosed food problems incorrectly as food allergy.

Food Intolerance

Food intolerance is another type of reaction to food. It is different to true food allergy because it does not involve an immune system reaction.  Most food intolerances are not as severe as food allergy. They can occur for the first time in childhood or adulthood and many are not able to be diagnosed by medical testing. It is important if a child has a severe reaction to food to see your doctor to rule out food allergy before eliminating foods or trialing exclusion diets.

There are a number of different types of food intolerance reactions. Some gut reactions such as irritable bowel syndrome cause symptoms such as bloating, flatulence, abdominal pain or loose bowel motions can be caused by FODMAPS. FODMAPS are natural sugars and starches, which are not well absorbed in the bowel of some people. This results in these sugars and starches being broken by bacteria down further down in the gut which produces gas and  perhaps some or all of the gut symptoms just mentioned. Once again it is important to speak to your doctor to make sure your symptoms are not related to something more serious.  A qualified dietitian can help you determine which FODMAPS sugars and starches you are reacting to and how to reduce the load of these in your diet to help manage your symptoms. Fructose or fruit sugar, which occurs in large amounts in some fruit, fructans (a starch found in wheat) and artificial sweeteners like sorbitol or mannitol (which also occur naturally in some foods) are common culprits.

Some symptoms such as migraines, eczema, hives and gut symptoms are sometimes, but not always, due to food chemical intolerance. This includes intolerances to the naturally occurring food chemicals salicylate, amine or glutamate or certain food additives such as colours and preservatives. If this is suspected, your dietitian may suggest an Elimination Diet. This diet is followed strictly for two to four weeks and, if symptoms improve, a series of food challenges are undertaken, under the supervision of your dietitian, to determine which food chemicals you are sensitive to. A diet with lower levels of these chemicals is then prescribed.

Coeliac disease results from a reaction in the body to gluten, one of the proteins in wheat. If you suspect you react to wheat, you should talk to your doctor about  ruling out coeliac disease before trialing a gluten free diet.  Many people unnecessarily follow a restrictive gluten free diet. However, if you do have coeliac disease, your dietitian can help you work out a varied and nutritionally balanced diet from the many gluten free grains and processed foods available. NPA are now offering a new DNA test for coeliac diease and gluten intolerance.

Your NPA Accredited Practising Dietitian will work closely with you and your doctor to establish what is causing your food related symptoms and develop a food plan to suit your needs.

Author:Christine Innes APD
Tags:AllergyCoeliac DiseaseFood IntoleranceIrritable Bowel Syndrome