Nutritional support and the immune system in cancer management. A critical review.

The nutritional state of the cancer patient is still a poorly defined parameter that most probably presents specific differences when compared with other states of denutrition. By definition, the immune response is altered in the denutritive condition. Factors such as amino acids, lipids, insulin, vitamin A, vitamin C and, zinc should be studied in more depth since existing studies have already shown that changes in plasma levels of these factors can modulate the immune response. Present information on hypernutrition is clearly inadequate and often difficult to evaluate, since it is based on nonrandomized trials in cancer patients, and for whom the relationship between nutritional state and the associated immune response was not clearly established. In addition, the effects on lymphocyte subpopulation functions within this context have not been adequately studied. These and other factors employed, is of limited interest and also expensive. We propose a more specific approach to nutritional therapy that would lead to a more specific modulation of the overall immune response.