Food Allergies and Intolerances

Reactions to foods can cause misery for many people and can even be life threatening for some. Finding out the foods that you are reacting to and learning how to avoid them can make a huge difference to how you feel.

What is the difference between food allergies and food intolerance?

Food Allergy

A food allergy is a reaction to a food that involves your immune system.  You can have symptoms from itching or rash through to the anaphylaxis that we often hear of in the news.  People can have an allergy to peanuts, fish or eggs among other foods.  Food allergies are tested for by taking a detailed history of your symptoms and reactions and running some blood tests with your GP.  The blood test that is needed is called a “specific IgE”.  It is important to only test for a very specific food based on the history of your symptoms.  It is rarely helpful to run an IgE test for all foods. 

Food Intolerance

Food intolerance does not involve your immune system and is usually linked to symptoms like bloating, diarrhoea or constipation, headaches or migraine.  These symptoms can have lots of causes so it is important to talk to your GP and rule out anything else that might be causing your problem.  Food intolerances are a common cause of Irritable Bowel Syndrome.  Bowel symptoms can also be a sign of Coeliac Disease and you may need a gluten free diet.

There are no reliable blood tests for food intolerances available at the moment.  To find out if you have a food intolerance, your dietitian will take a detailed history of your symptoms and the foods that you think are triggers.  From there they will advise you on an elimination diet that may cut out one or two foods or may cut out a larger number if necessary.  If you have been diagnosed with irritable bowel syndrome, your dietitian may recommend a Low FODMAP diet.