Navigating the world of food allergy, food intolerance and food sensitivity can be very confusing. The key thing to remember is that a food allergy involves the immune system, while food intolerance and food sensitivity involve the digestive system.
It is also worth knowing that, depending on the severity, a food allergy can be deadly. Food intolerance and food sensitivity can be pretty uncomfortable, with symptoms that include pain, cramps, bloating, discomfort, gas, diarrhea, constipation and further embarrassing symptoms, but are not usually life-threatening.
How You Can Identify a Food Allergy
Common food allergens include nuts and dairy, but anything can be an allergen. If you have a food allergy, symptoms can be mild. It is best to avoid allergens by making sure that you know the ingredients in your food and avoid places where your allergen may be served.
How You Can Identify a Food Intolerance or Food Sensitivity
Food intolerances and sensitivities are much more common than allergies. The reaction takes place in the digestive system, but only Celiac disease involves the immune system, which makes it a more complicated disorder. If you have Celiac disease, you must avoid gluten. Gluten is a naturally occurring protein found in wheat and grains, and is often an additive in commercially produced foods.
Common food intolerances include lactose intolerance. Lactose intolerance can be remedied by avoiding dairy products that contain lactose and can also be resolved by taking an enzyme that helps the digestive system to digest lactase. Not all dairy products contain lactose, so it is different than a food allergy to dairy, which means complete avoidance of dairy products because the allergen in that case is protein.
A less common food intolerance is sucrose intolerance. Sucrose intolerance is also known as Genetic Sucrase-Isomaltase Deficiency (GSID), SI Deficiency, Disaccharide Intolerance and Congenital Sucrase-Isomaltase Deficiency (CSID). People with sucrose intolerance either lack or have low levels of the enzyme needed to digest sucrose. Depending on the cause of sucrose intolerance, which can be genetic or caused by other conditions and infections, sucrose intolerance has different treatments.
Food sensitivity is closely related to food intolerance. It is not deadly, and most often occurs as a reaction to food additives, artificial ingredients and occasionally natural toxins.
Sources:
http://www.healthline.com/health/allergies/food-allergy-sensitivity-difference#Overview1
http://www.mayoclinic.org/diseases-conditions/food-allergy/expert-answers/food-allergy/faq-20058538