Nutritional modulation of behavior and immunocompetence

Alterations in nutritional status can have profound effects both on the immune system and on behavior. For example, a severe deficiency such as that of niacin can lead to the dementia associated with pellagra; a severe thiamin deficiency results in Wernicke's encephalopathy. Studies in children in Third World countries have clearly demonstrated the devastating effects of protein-energy undernutrition (PEU) on immune competence and the development of infections. Nutritional deficiencies in older persons rarely present with such clear-cut changes but rather are often seen as borderline deficiency states. The following sections will briefly explore the putative effects of borderline nutritional status on the immune system and behavior in older persons.John E. Morle