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More and more people are avoiding foods for many different reasons.

Food businesses preparing food and selling it to the public may be asked by their customers about:

  • ingredients in foods that are on sale
  • possible contamination from other dishes or products during preparation and service

Examples of why people avoid foods

  • They are allergic or intolerant to a particular ingredient or food
  • They want to make healthier food choices
  • For health reasons (for example they could have a medical condition such as diabetes, high cholesterol and/or high blood pressure)
  • For religious reasons (for example they may want to observe dietary laws such as kosher, halal, Hindu or Sikh vegetarian)
  • For moral or ethical reasons (for example they may prefer Fairtrade, organic, vegetarian or vegan)
  • Personal choice or preference

Food sensitivities

Some people have a reproducible food sensitivity such as a food intolerance, food allergy or coeliac disease.

Coeliac disease

Coeliac disease is not an allergy. It is an auto-immune disease, which means that the body produces antibodies that attack its own tissues. For people with coeliac disease this attack is triggered by gluten, a protein found in wheat, rye and barley. Some people with coeliac disease also react to oats. Symptoms of coeliac disease can range from mild to severe and can include: bloating, diarrhoea, nausea, wind, tiredness, constipation, anaemia, mouth ulcers, headaches, weight loss, hair loss, skin problems, short stature, depression, infertility, recurrent miscarriages and joint/bone pain.

Some symptoms might be confused with irritable bowel syndrome (IBS) or wheat intolerance, while others might be related to stress or getting older. As a consequence, it can take some time before an accurate diagnosis is sought, or made. After diagnosis and starting a gluten-free diet these symptoms typically cease.

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Food intolerance

  • A food intolerance is more common than food allergy and could affect one in five people.
  • It doesn't involve the same immune system mechanism as food allergy.
  • There are consistent symptoms after eating particular foods.
  • Symptoms typically include gastro-intestinal upset.

Lactose intolerance

  • Lactose can be found in milk and other dairy products.
  • Lactose intolerance is particularly common in people with Chinese and African-Caribbean backgrounds.

Food allergies

Some people need to avoid certain foods because they are allergic to them.

  • Food allergies involve specific antibodies, mainly Immunoglobin E (IgE), in the immune system. For each food, the body manufactures a specific antibody.
  • Immunoglobin E antibodies are designed to recognise and attack disease-causing substances such as pathogens and parasitic worms.
  • Allergic (atopic) people have immune systems that are programmed to treat ordinary proteins from foods and other things as if they are a threat (for example cats, dogs, horses, insect stings, pollen etc.).
  • IgE is a two-stage process. The first stage of IgE mediated food allergy is sensitisation when the body recognises a particular substance as harmful but no symptoms are experienced. The second stage is where symptoms occur.

Food allergy symptoms

Mild to moderate symptoms may include:

  • a swollen throat or lips
  • difficulty in swallowing or speaking
  • coughing, wheezing and shortness of breath
  • alterations in heart rate
  • skin rash and/or itchy skin
  • abdominal cramps, bloating, diarrhoea, nausea and vomiting
  • sore, red and/or itchy eyes
  • runny or blocked nose
  • dry, itchy throat and tongue

If these develop, severe symptoms might involve:

  • difficulties with breathing, including asthmatic symptoms
  • a sudden feeling of weakness (a drop in blood pressure)
  • a sense of impending doom
  • collapse
  • unconciousness

If the symptoms are severe enough food allergy can be fatal.

For more information on food allergy symptoms see the 'In the body' section.