Dietary n-3 polyunsaturated fatty acid modulation of immune cell function before or after trauma.

We describe the role of increased eicosanoid production in inducing immunodepression associated with shock and trauma and the potential mechanisms by which prostaglandins produce immunosuppression. The effects of prefeeding with a diet high in n-3 polyunsaturated fatty acids (PUFAs) in preventing trauma-induced immunosuppression, and of such a diet on cellular immunity in patients after trauma are described. The potential mechanisms by which enteral diets containing n-3 PUFAs produce beneficial effects are also discussed. Although there is controversy concerning the immunomodulatory mechanisms of this diet, most of the information available indicates that dietary supplementation with n-3 PUFAs may prevent immunosuppression after trauma. Further studies are needed, however, to determine the precise composition and duration of supplementation with n-3 PUFAs that prevent the deleterious immune responses but do not alter normal immunoresponsiveness.