Food intolerance

We hear a lot about food allergies and intolerance these days. Almost every health condition and intolerance is talked about as being caused by a reaction to a food. Although many people do have allergies and intolerances, they are not a common as you might think and it is very important to always get properly diagnosed before you start to cut out foods.


What is a Food Intolerance?

Unlike a food allergy, a food intolerance does not involve your immune system and it is extremely rare for a food intolerance to be life-threatening. A food allergy always involves your immune system, whereas a food intolerance can have lots of different causes.


What causes Food Intolerance?

There are lots of things that can cause food intolerance. One of the most famous food intolerances is lactose intolerance. Lactose is a type of sugar found in cow’s, goat’s and sheep’s milk. We need an enzyme called ‘lactase’ to helps us to digest lactose. About 5-10% of people in Ireland do not make enough lactase to be able to digest lactose. This means that the lactose makes its way down through the bowel and into the large bowel. This leads to a specific type of diarrhoea as well as lots of bloating and gas.

Other common food intolerances can be to gluten, a protein found in wheat, or a range of substances found in foods called ‘FODMAPs’. FODMAPs are a group of different kinds of sugars (such as fructose and lactose) and polyols. For some people with Irritable Bowel Syndrome eliminating foods that contain FODMAPs can help. Be careful: A low FODMAP diet is extremely difficult to get right and you do need to see a qualified dietitian trained in FODMAPs to get results.


How can I get tested for a Food Intolerance?

As food intolerances has so many causes, you do need to speak to your GP. It is important that you start with your GP to rule out any other causes for your symptoms as well. You will need to rule out problems like coeliac disease if your problems are related to your digestion. If you cannot find any other cause for your symptoms and you think it might be related to food, then the next step is a qualified dietitian who is a member of the Irish Nutrition and Dietetic Institute.


Seeing a Qualified Dietitian

There are a number of ways to diagnose a food intolerance but one of the best ways is an elimination diet. There are lots of tests that people use to diagnose food intolerance (e.g. IgE testing, Vega testing and hair analysis). However, few of these tests have been shown to be of much value in diagnosing food intolerances, so be careful of spending your money on these tests before you see your dietitian. Your dietitian will be able to look at the history of your problem and advise on which foods to eliminate. Getting expert advice is important as you may not realise all of the different places the food you are intolerant to can turn up. Many people avoiding dairy forget to look out for milk in bread and biscuits and so on.  Your dietitian may also find other causes for your problems – you may be missing out on key nutrients or you may need to increase your fibre.

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