Some people are allergic to certain foods. True food allergy such as peanut allergy can be a serious and life-threatening medical condition causing swelling in the mouth, tongue, face and airways and this sometimes needs emergency medical care. These reactions are caused by the body’s immune system and usually come on within minutes or even seconds of eating the food. Luckily this type of allergy is rare.
Food intolerance is not the same thing as a food allergy and is more controversial. Some people find that they are sensitive to some foods and eating these foods can make them feel unwell in a more vague way such as causing bloating, abdominal pains, cramps, joint pains or fatigue. Sometimes these symptoms come on a few hours or even days after eating the suspected food which means that it is difficult to pin down the trigger. Sometimes the symptoms vary and difficult to describe. Food intolerance is not life-threatening but can cause distress as it may be difficult to diagnose leading to frustration and worry. Some people who are intolerant of certain foods such as lactose in milk lack the enzymes in the body needed to break down these foods, causing diarrhoea if they eat dairy-containing foods. Others find that they react to certain naturally occurring chemicals in food such as tyramine in cheese which can trigger migraines. Some people are also sensitive to food additives such as sulphites used to preserve food.