## What is the difference? Food allergies occur due to disorders in the immune system, while food intolerances are associated with improper functioning of the digestive system. Simply put, certain foods are not broken down properly due to enzyme deficiencies, sensitivities to additives or natural chemicals found in food. [Allergies](https://ul.orna.me/KOge/librarydisease?id=21) can lead to anaphylactic shock. Food iIntolerances, with very few exceptions, do not cause such severe consequences. Allergies can be triggered by even a very small level of allergen. In food intolerances, the strength of the reaction is directly related to the amount of irritant. > Generally, people with food intolerances can afford a small amount of "forbidden" food without experiencing harm to health. ## What causes food intolerance most often? Individual intolerance to foods is caused by ===a number of substances: - Lactose: a type of sugar found in milk and dairy products; it is the most common type of intolerance. - Gluten: found in wheat, barley and rye. - Fructose: found in fruits and honey. - Histamine: found in wine, aged cheese, chocolate, peanuts, legumes, brewer's yeast, and strawberries. - Caffeine: found in coffee, tea, and energy drinks. - Alcohol sulfite: found in wine, beer and cider. - Monosodium glutamate: found in ripe fruit, cured meats, and salted foods. - Salicylates: found in cucumbers, tomatoes, dill, grapes, tangerines, oranges, apricots, nectarines, dates, guava, kiwi, watermelon, melon, plum, mango, passion fruit and honey. - Amines: found in meat, fish, seafood, wine, cider, beer, dairy products, spinach, tomatoes and foods with yeast. ## What are the symptoms of food intolerances? Typically, food intolerance is accompanied by stomach pain, flatulence, abdominal bloating, diarrhea, irritable bowel syndrome (IBS), headache, rashes, and the formation of mouth sores. Typically the reaction to the irritant occurs a few hours after consuming the "intolerant" product, and can last for hours or days. ## How is it diagnosed? The most common test for food intolerance is a doctor-controlled elimination diet consisting of two stages. Stage 1: all foods that are suspected to cause food intolerance are eliminated from the diet. Stage 2: these products are reintroduced one by one. Each reintroduction is monitored for 2-3 days before the next product. Both of these stages take 4-6 weeks. During this time, it is necessary to keep a food diary to note the physiological reactions to food. Also, if fructose or lactose intolerance is suspected, doctors may use a breath test. > When you identify the foods that cause a reaction, you should exclude them from the diet for at least three months. Incase of severe symptoms, this might be required for up to a year. Then, gradually, they can be reintroduced.