What's the difference between a food intolerance and a food allergy?

Immune response. A true food allergy involves a specific immune response by your body, usually with allergic antibody directed at the implicated food, though other mechanisms can occur. Food intolerance simply implies that a patient does not tolerate a food, with the most common exampl being lactose intolerance, wherein the body does not make enough lactase to digest lactose.
Immune v not immune. Intolerance in a medical sense means that the body cannot fully process the nutrient. For lactose intolerance, there is either no or not enough enzyme to handle the ingested lactose, and the excess lactose causes symptoms. An allergy is the immune system responding to a food as if it was dangerous (it sees the food almost like an infection).

Related Questions

What's the difference between food allergy and food intolerance?

Mechanism. Food allergies are mediated by the ige antibody and it takes only a small amount to lead to a severe even anaphylactic allergic reaction and rarely death. Food intolerance is GI symptoms of bloating, gassy, crampy belly pain and diarrhea after eating usually larger amounts of a food. Intolerances are more common (like lactose intolerance) and are not mediated by ige antibody and not life ending. Read more...

Need advice on what is the the difference between having a food intolerance and having a food allergy?

See below. Food allergy: usually comes on suddenly. Small amount of food can trigger. Happens every time you eat the food. Can be life-threatening food intolerance: usually comes on gradually. May only happen when you eat a lot of the food. May only happen if you eat the food often. Is not life-threatening. Read more...