Monounsaturated fatty acids and immune function.

Animal studies generally support the idea that olive oil, rich in oleic acid, is capable of modulating functions of cells of the immune system. Importantly, several studies have demonstrated suppressive effects of oleic acid-containing diets on in vivo immune responses. There is some evidence that the effects of olive oil on immune function in animal studies are due to oleic acid rather than trace elements or antioxidants, although the evidence is not conclusive. In contrast to animal studies, consumption of a MUFA-rich diet by healthy human subjects does not appear to bring about a general suppression of immune cell functions. The lack of a clear effect of MUFA in human subjects is likely to be attributable to the much higher level of MUFA used in animal studies, which are not readily achievable or realistic in human studies. In conclusion, there is potential for MUFA to modulate immune function, but the effects in humans are likely to be far more subtle than those reported in animal studies. It remains to be seen whether MUFA will be clinically useful in immunonutrition.