Food allergies and intolerances

Food allergy and intolerance are commonly used terms, being linked to digestive or skin symptoms, weight issues and respiratory problems amongst others. The terms are often used interchangeably, but in fact are quite different conditions.

People often worry that chronic symptoms may be due to a food allergy or intolerance, but may be unclear as to what each term means.

Food Allergies

A food allergy involves the body’s immune system and is caused by the body mistakenly identifying a protein from a food as being harmful and reacting to it. Often, reactions are immediate and can occur after being exposed to very small amounts of the food. Food allergy will occur each time the food is eaten. Food allergies can be severe or even life threatening.

Food Intolerances

A food intolerance is very different from a food allergy in that it does not involve the immune system. Food intolerances are generally caused by the body’s inability to digest a food, or an ingredient in food. This in turn causes a chemical reaction in the body which causes symptoms. These symptoms can vary in intensity with the dose of the food or ingredient, if very small amounts are eaten the symptoms may not occur at all whilst symptoms may be quite severe with larger doses of the food.

Diagnosing Food Allergies

Food allergies can be diagnosed using blood tests, skin prick tests or oral food challenges. These tests should only be carried out by qualified professionals, you can access an appropriate professional by consulting your GP who will refer you on.

Skin Prick Testing

This involves minute amounts of the suspected allergen being pricked into the skin to see if a reaction is seen.

Blood Testing

This involves the measurement of IgE antibodies in your blood

Oral Food Challenges

This involves being given very small amounts of the suspect food being given and monitoring for reactions.

There are many commercially available food allergy or intolerance test kits available. These should be avoided as they have no scientific basis. The results often include suggestions of multiple foods which should be avoided, this can result in very limited and nutritionally unbalanced diets. You should always be given the opportunity to see a registered dietitian if you have been diagnosed with any food allergy or intolerance, in order to ensure that your diet remains healthy and nutritionally adequate.

Diagnosing Food intolerances

Diagnosing food intolerances can be a little more tricky than diagnosing food allergies. As there is no role for the immune system, blood tests or skin prick tests aren’t effective.

The simplest way to detect a food intolerance is with a trial elimination. This involves the removal of foods most likely to cause symptoms for a period of 2-4 weeks, during which time symptoms should settle, this is then followed with a staged reintroduction of the removed foods. When the culprit is reintroduced, symptoms will return.

Elimination diets should always be undertaken with the support of a qualified dietitian who can plan an elimination which will be effective and prevent any issues with the diet not being nutritionally adequate.

What to expect

You should always expect to have to fill in a food and symptom diary prior to attending an appointment with a dietitian. The dietitian will use this to assess your symptoms and identify likely culprits.

Sometimes people who feel that they have symptoms of a food intolerance may find that their symptoms are the results of some eating habits and are instead the result of low intakes of dietary fibre, inadequate hydration and lack of certain vitamins or minerals.

A dietitian will be able to give reliable advice on the cause of your symptoms and advise you on the best treatment. For further information about food allergy or intolerance, please contact Stanner Nutrition Clinic by clicking the link here.

Mairi Wilcock, Registered Dieititian

I offer effective and reliable support for many digestive and gut problems, as well as heart conditions, weight management and diabetes.

For a free, no-obligation chat, book a 15 minute discovery call with me to find out how I can help you.

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