Non-allergic food hypersensitivities, such as intolerances, arise because the body is unable to digest or reacts to certain naturally occurring component of foods, i.e., lactose or fructose, or, less commonly, food coloring, additives or preservatives. Non-allergic food hypersensitivities do not involve the immune system and are much more common than food allergies.
Food allergies arise due to the body’s immune system reacting to certain, normally harmless, allergy-triggering substances (allergens) in food. These allergens are usually proteins. Proteins are one of the essential nutrients that make up the body, together with vitamins, minerals, carbohydrates and fat. Other components in food, such as lactose and sugar, do not act as allergens.
Certain allergens cause more reactions than others.