DO YOU KNOW THE DIFFERENCE BETWEEN FOOD ALLERGY AND FOOD INTOLERANCE?

A food allergy is a reaction which involves your immune system when your body reacts to certain foods. It can be mild, but can also be very serious for some people. Proteins contained in foods can trigger immediate (within two hours) or delayed symptoms (up to several days later). Symptoms of a food allergy can affect many parts of the body and can also affect different parts at the same time.

Food allergies occur when the immune system mistakenly identifies a protein in food as a harmful substance. The immune system then produces antibodies to which the allergen binds to, triggering the release of chemicals, such as histamine, which cause allergic reactions, such as itching and swelling of the skin, eyes or lips or gut reactions such as vomiting and diarrhoea. Other more dangerous symptoms can include breathing problems and in rare cases an extreme allergic reaction called Anaphylaxis, which can interfere with and stop breathing resulting in a medical emergency which requires immediate medical attention. Delayed reactions to foods still involve your immune system, but there is a different type of immune reaction involved. Symptoms typically occur in the gut, vomiting, diarrhoea or constipation and can also affect the skin e.g. Atopic Eczema. The most common allergies in adults in the UK are to peanuts, tree nuts, fish, shellfish and also to raw fruit and vegetables such as apple, peach and kiwi.

A food allergy is different from having a food intolerance, as a food intolerance does not involve the immune system or cause an immune response. However, a food intolerance can still cause unpleasant symptoms such as bloating, diarrhoea and tummy pain, which usually occur a few hours after eating the food you are intolerant to. Other symptoms can include headache, feeling tired or exhausted, feeling sick, constipation, joint pain and rashes and can last for a few hours or days. The most common food intolerances include lactose intolerance, which is mainly caused by lack of the enzyme lactase which helps to digest lactose, (the sugar found in milk and dairy products). Histamine intolerance occurs when the body has an adverse reaction to histamines contained in foods, and common trigger foods are red wine, dairy products such as strong cheeses, processed or smoked meats, dried fruits and tomatoes. Sometimes people also have intolerances to foods which contain a substance called Salicylates which is found in a wide variety of plant foods.

In the UK there are 14 common allergens that food businesses must inform the public if they use them in any foods or beverages. The 14 allergens are: Celery, cereals containing gluten (such as rye, wheat and barley), crustaceans (e.g. prawns, crabs and lobsters), eggs, fish, lupin, milk, molluscs (e.g. mussels and oysters), mustard, peanuts, sesame, soybeans, sulphur dioxide (sulphites) and tree nuts (e.g. almonds, hazelnuts, walnuts and cashews). Allergens must be clearly marked on the package of prepacked foods or ready meals and any foods you buy from bakeries, butchers or deli’s must also provide you with allergen items. A restaurant or café must provide you with allergen information in writing, and staff should ask about allergies when taking any food orders.

If you are advised to cut out a complete food group from your diet such as dairy, try to make sure the foods you replace them with are nutritious, and are not ultra-processed containing chemicals such as stabilisers and fillers or are high in fat and sugar. Most supermarkets have ‘free from’ ranges which can offer healthy alternative choices, for example gluten free products are becoming more common and the taste and texture has improved. When cooking from scratch Google alternative ingredients to adapt favourite recipes. When eating out check the menu and speak to the restaurant beforehand and if going on holiday preplanning is essential, letting airlines and hotels know of your allergy and taking any medication or an Epi Pen if prescribed, just in case. If in doubt about any foods do not eat them and choose a food you know is safe and also ensure your holiday companions know what to do should an emergency arise.

In the case of allergies, it is better to avoid trigger foods, but in the case of intolerances a reduced intake may help to improve symptoms. However, if you think you have a food allergy or intolerance, book an appointment with your GP who will refer you to an expert to diagnose your allergy/intolerance and help you to manage it.

Nicola Rose DipCH BSc (Hons) RNutr is a fully Registered Nutritionist and Clinical Hypnotherapist. She worked for a specialist NHS weight management service for many years. If you have any questions on this article please email Nicola at info@nourishmindandbody.co.uk