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What is food intolerance?
Food intolerance is a type of food sensitivity that refers to all non-immunological reactions to food. Food intolerance reactions are different to food allergies as they are caused by food additives and naturally occurring food chemicals as opposed to specific food proteins as is the case for allergies. Some food intolerances are caused by defects in the body’s ability to digest food. Such examples include lactose (sugar in milk) intolerance and fructose (sugar in certain fruits and vegetables) intolerance.
How common are food intolerance reactions?
Food intolerance reactions are more common than allergies and are estimated to affect up to 25% of the population (children and adults)1. Any age group can be affected and the sensitivity tends to be lifelong.
What are the symptoms?
Food intolerance can result in a range of symptoms that can affect the following bodily systems:
- Gastrointestinal tract: bloating, diarrhoea, constipation, stomach pain
- Respiratory tract: itchy, runny nose, sinus congestion
- Nervous system: irritable behaviour, overactivity, headaches, migraines, fatigue
- Skin: nappy rash, eczema, hives, swellings, mouth ulcers
Food intolerance is hereditary and usually involves the same bodily system across generations.
Remember:
- Food intolerance is a type of food sensitivity that refers to all non-immunological reactions to food.
- Food intolerances are different to food allergies.
- Food intolerance reactions are more common than allergies and are estimated to affect up to 25% of the population.
- Food intolerance can result in a range of symptoms including our skin, digestive tract and nervous system.
What types of foods may cause reactions?
People with food intolerance can commonly react to several chemicals, all of which can be found in a wide range of foods. Such chemicals include:
- Salicylates (found in certain fruits and vegetables).
- Amines (found in fermented products and certain fruits and vegetables).
- Glutamates (such as MSG and naturally occurring glutamates in certain fruits and vegetables).
- Preservatives such as nitrates (in processed meats), propionates (in bread) and benzoates (in flavoured drinks) and sulphites (in dried fruit).
- Artificial colours.
Severity of the reaction depends on the dose of chemical consumed and tends to be delayed (hours to days) which makes it difficult to identify the cause.
How is it diagnosed?
Unlike food allergies, there are currently no reliable clinical tests to diagnose food intolerance. It is recommended that people with a suspected food intolerance seek professional advice from an Accredited Practising Dietitian (APD) who will advise on the best dietary approach needed to identify the problem foods. An APD will also ensure that the individual has adequate nutrition both during the investigation and after diagnosis.
1. NSW Government Food Authority, Allergy and intolerance [Accessed 16 August 2021]. Available from https://www.foodauthority.nsw.gov.au/consumer/life-events-and-food/allergy-and-intolerance.
Remember:
- People with food intolerance can commonly react to several chemicals, all of which can be found in a wide range of foods.
- Severity of the reaction depends on the dose of chemical consumed and tends to be delayed.
- There are currently no reliable clinical tests to diagnose food intolerance.
- People with a suspected food intolerance should seek professional advice from an Accredited Practising Dietitian to identify problem foods and ensure a nutritionally adequate diet
Produced by Nutrition Australia Vic Division, October 2014. Reviewed August 2021.
