“When science first began to probe the causes of common allergic symptoms, it was found that when exposed to specific substances, called allergens or antigens, allergic individuals developed an excess of an antibody called immunoglobulin E (IgE). The IgE antibodies react with allergens to release histamines and other chemicals from cell tissues, producing various sensitivity symptoms. In other words, the immune system mistakenly identifies harmless substances as dangerous invaders and activates an antibody attack to defend the body.
“There are between 35 and 50 million people in the United States alone who suffer from some type of significant allergy. [However…]
“Part of the difficulty in determining the exact number of allergy sufferers lies in how broadly or narrowly one defines the term. Medical doctors and scientists often maintain a narrow definition, asserting that the only true allergies are those that result from the activation of IgE antibodies (known as Type I Hypersensitivity Reactions). However, millions of people experience symptoms of sensitivity to a food or other substance without the IgE antibody reaction and often without any increase of antibodies of any type being detected. These people can be said to have a reactivity, sensitivity, or intolerance to particular substances.”