[Immunonutrition--can we see the light?].

Nutrition has an established effect on patients' outcome and is an integral part of medical treatment. Nutrition should provide the exact patient's needs since both undernutrition and overfeeding increase the morbidity and mortality risk. In addition to providing energy and essential nutrients, nutrition can modulate the immune and inflammatory response. Immunonutrition usually refers to the use of the amino acids L-arginine and glutamine, nucleosides and omega-3 polyunsaturated fatty acids. The supplementation of one or more of these nutrients enhanced the immune response and improved the prognosis of specific groups of patients. However, these products are expensive, the exact safety profile is unknown, and there are unanswered questions regarding the optimal dose and treatment duration, the optimal combination of nutrients, and the specific groups of patients that will benefit from such treatment are yet to be defined.