Lipids and immunology.

Dietary fat plays an important regulatory role in the pathogenesis of a range of immune reactions. In food allergies, especially in type I allergic reactions, dietary fat can modulate the development of clinical symptoms through influencing the production of immunoglobulins (Ig), cytokines and chemical mediators. In general, polyunsaturated fatty acids (PUFA) of the n-3 family in relation to those of the n-6 family reduce the production of eicosanoids and hence, mitigate hypersensitivity. In this context, it is interesting that conjugated derivatives of linoleic acid (CLA) reduce the production of eicosanoids and regulate the production of Ig in a manner favourable to the prevention of allergic reactions. Trans monoene fatty acid (that is, elaidic acid), in relation to cis monoenoic fatty acid (that is, oleic acid), also behaves as an anti-allergic agent through interfering with the desaturation of linoleic acid. The information available indicates that different dietary fats influence differently the immune indices related to food allergic reaction. The effects appeared to be readily modified by the combination of food components, including dietary fats. Thus, an appropriate combination of a specific fat or fatty acid may be one approach to the regulation of allergic reaction.