The detenmnation of optimal nutritional status has traditionally been based upon generalized parameters such as weight gain and body fat levels. Vitamin and mineral requirements were often related to the intakes needed to prevent overt signs of deficiency diseases such as beriberi or scurvy. However, in the past decade or so, there have been intensive investigations to determine the subtle changes in physiological functions associated with marginal micronutrient intakes. There is a growing consensus that immune system activities are very sensitive indicators of micronutrient status. During this decade, there has also been a rapid expansion of research in the role of free radicals and antioxidants in the major chronic diseases which afflict mankind( i.e. cancer, cardiovascular disease,and autoimmune disease). The main function of antioxidant nutrients in an appropriate diet is the prevention of oxidative damage to cells and their physiological functions. Antioxidant nutrients counteract free radicals and damaging oxidative actions on cell membranes. Since the cells of the immune system are rapidly differentiating and proliferating, such dividing and transforming cells are particularly susceptible to damage by oxidation. The interactions of antioxidant nutrition and immune system activities and disease resistance are therefore logical areas for research. Thus, the objective of this symposium was to bring together the leading investigators who have examined the immunological effects of dietary essential nutrients which share the capacity to act as antioxidants.

Intuitively, we realize that animals that are well fed and well cared for are healthier than animals that are not well fed or well cared for. Although nutritionists have long been concerned with minimum nutrient requirements for maximal growth rate and maintenance, it has been only recently that investiagators have begun to look at the nutritional requirements that provide optimal health. The increasingly sophisticated methods of immunology have allowed investigators to define indicators of resistance to disease such as cell mediated immunity, lymphocyte functions, and macrophage functions. When these immunological tools are combined with the classical methods of nutrition research it is possible to determine how dietary constituents affect each of these cellular immune systems, and to gain an overall understanding of how these systems affect resistance to disease. This symposium was organized to bring together people working on various nutritional problems that have an interrelationship to resistance to disease, so that this rapidly expanding area of nutritional immunology could be reviewed. We felt that the Agricultural and Food Division of the American Chemical Society was an ideal forum to present this material. In relating nutrition and infection, two areas of importan e must be considered: (1) public health, i. e., the prevention and treatment of human disease and metabolic disorders; and (2) live stock and poultry production. The production of meat, fibre, and animal materials continues to be a more intensive operation in the agricultural system of this country and the world."