IS IT INTOLERANCE OR ALLERGY?
Food allergy is an immune reaction to foods. Food intolerance is better understood as a chemical sensitivity which is not immune mediated. The difference can be difficult to understand sometimes, as symptoms may be similar at times. Importantly, given that food intolerances do not involve the immune system they do not cause severe allergic reactions like anaphylaxis. Occasionally, substances within foods can increase the frequency and severity of non-specific symptoms like migraines, skin rashes or irritable bowel. Food intolerance does not show on allergy testing and the mainstay of treatment is to limit consumption (not necessarily complete avoidance) of the triggering food/ingredient, while ensuring nutritional adequacy. Examples of these include lactose intolerance, gluten intolerance or chemical sensitivity to natural or artificial food chemicals like amines or MSG.
WHAT ABOUT ARTIFICIAL PRESERVATIVES?
Preservatives usually cause sensitivity reactions rather than allergic reactions. The vast majority of true allergies are to food proteins rather than chemicals. True allergic reactions to food additives are rare and generally occur only to preservatives that have a natural protein origin. Avoidance of specific preservatives is the main treatment ensuring an otherwise healthy diet.
AND OTHER SUBSTANCES LIKE SULFITES?
Sulfites are preservatives used in some drinks (cordial, juices, beer), foods (gravies, sauces, syrups, jams) and occasionally medications (eye drops and creams). Sulfite sensitivity can cause allergy-like reactions (intolerances), most commonly asthma symptoms in those with underlying asthma, sometimes allergic rhinitis (hay fever), occasionally urticarial ( hives) and very rarely anaphylaxis. Wheezing is the most common reaction. Sensitivity to sulfites is a different condition from sulfonamide antibiotic allergy. People who react to sulfites do not need to avoid sulfates or sulfurs (commonly found in soaps, shampoos and gardening products). Avoidance is the mainstay of therapy