Hypersensitivities Mechanisms

Hypersensitivities Mechanisms
Adverse reactions to food additives are caused by several mechanisms.

Food additives are ingested irregularly and in small doses. Additives are usually low by molecular weight chemicals, unlike many high molecular weight proteins which are potent allergens.

There is very little evidence of an immunological basis in reactions caused by food additives.

Adverse effects due to a various pharmacological or other mechanisms are much more common.

Many authors avoid the use of the terms allergy and atopy in connection with food additive reactions and prefer hypersensitivity or tolerance instead.

Terms such as false allergies, allergomimetic, reactions, or pseudoallergy have been suggested.

All these titles emphasize the nonspecific, nonimmunological nature of these reactions.

It has been observed in several studies that there is a dose response relationship with these reactions. A small amount of the agent is harmless, but a larger amount causes symptoms.

This better suits the concept of intolerance than immunologic sensitization.

Many patient suffering from food additives reactions have an atopic constitution and symptoms such as eczema and asthma.

Atopic subjects are more sensitive to numerous irritating environmental factors, including food additives, than the nonatopic population.

Atopic subjects have a particular tendency to release histamine after certain foods and additives that posses a histamine releasing action.

There appear to be more reactions caused by additives in adults than in children. The reason is obscure, but cumulative or slow development of intolerance may occur.

On the other hand, adults often have psychosomatic symptoms and are influenced by television programs and articles in journal and newspapers dealing with the adverse effects of food additives.
Hypersensitivities Mechanisms