45% of the population suffer from food intolerance which, whilst not life threatening can cause many different symptoms. Digested foods are usually broken down into smaller fragments for easy absorption in the body. Sometimes larger fragments can pass through into the blood stream, causing the body to react to them as invaders, attacking them using antibodies called immunoglobulin G (IgG). IgG antibodies to foods are linked to inflammation in the body. Symptoms can be slow to develop and can take hours or days to appear. Food intolerance can be reversible.
Food allergy is very different; it produces reactions very quickly and can be life-threatening. Food allergies are life-long.