Fat intake and immune response.

Changing the concentration or the type of fat intake impacts several aspects of the immune response involving lymphocytes, monocytes, and neutrophils. An increase in the intake of fat inhibited immune response in humans and in several animal models. Polyunsaturated fatty acids (PUFA) of N-6 type lowered immune response in several animal models, but a moderate increase in the consumption of N-6 PUFA by humans did not have any detectable adverse effect on the immune response. In humans, several indices of immune response were inhibited by the N-3 PUFA, but in animals both inhibition and stimulation were found, depending upon the species, the fatty acids used and the index being examined. Whether the absolute amounts or the ratios between individual fatty acids or fatty acid classes are critical in determining their effects on immune response need to be investigated. Manipulation of fat intake has already found limited success in managing some of the disorders of the immune system and further use of this treatment is anticipated.