Adverse reactions to foods.

The discovery of IgE in the mid-1960s resulted in a widespread view that allergy was the basis of most adverse reactions to food, but it is becoming increasingly clear that other, as yet poorly understood, mechanisms are responsible in the overwhelming majority of cases. This, together with the proliferation of popular literature on "food allergy" has resulted in considerable confusion in the minds of both the public and the medical profession on the subject. In the majority of patients presenting with food intolerance, recognized or otherwise, symptoms are precipitated by various small, non-immunogenic organic molecules present in the food as natural or added ingredients. These reactions are pharmacological rather than immunological in nature, although in some situations they may share a final common pathway with true allergic reactions, resulting in similar symptoms.