Nutritional influences on immunity

There is no doubt that nutrient deficiencies and excesses can influence immune responses. Despite advances in the development of therapeutic agents, a competent immune system is crucial for prevention and resolution of disease. Leukocytes are some of the most metabolically active cells in animals. We know that growing animals require nutrients to sustain growth and reach their full potential, whether that is size, strength, speed, or agility. We do not expect kittens to grow or greyhounds to run without provision of adequate nutrients. To expect the immune system to function in the face of nutrient deficiency neglects our knowledge of the physiological needs of metabolically active tissues. Immune responses may be modified through dietary manipulations. However, the clinician must answer the question "to what end or consequence will the response be changed?" No "golden" nutrient ensures an appropriate immune response in all conditions, just as no "golden" drug heals all diseases. Our knowledge of nutrient-immune system interactions is increasing. Yet, for all of the current knowledge of nutrient effects on immunity, the words of Dr R.K. Chandra hold sterling advice, "Moderation is a good dictum in biology and medicine, and it applies equally to nutritional immunology."