severe stress reaction does not necessarily predict poorer recovery, and recovery may be the critical parameter for assessing potential response to future stress and long-term health of the immune system.
Factors influencing immune response of the individual to potential environmental pathogens at any single point in time include such interacting host factors as genetic predisposition, general fitness or state of health, previous history of exposure, and nutrient status. Although immunization can be protective against known pathogens (that is, where exposure can be predicted), nutrients may support general improvement of immune function or act as specific cofactors, which suggests that repletion or supplementation could ultimately provide an approach for optimizing immune response.
Evidence is increasing that nutrients are involved specifically with the development of an immune response (Cunningham-Rundles, 1993). Further, current studies suggest that key elements in the diet, for example some trace elements, have a profound influence on immune response even within a period of days (Prasad et al., 1988). Conversely, nutrient deprivation may have long-term consequences, especially when these deprivations are unrecognized and uncorrected (Ohshima et al., 1991).
Development of a rational experimental design for the measurement of general immune function and how this may relate to future immunity is important if the operation of these nutrition-immune function interactions is to be clarified in essentially healthy persons under stress. Quantitative measures of response to a test stimulus may indicate but may not predict response to an unforeseen pathogen. In contrast, the relationship among immunization, subsequent development of serum antibody titer, and protection against encounter with the immunizing pathogen can be more easily quantified and predicted.
The subsequent discussion presents some key elements in the evaluation of immune response. Some of the key questions that must be considered are:
The rationale for undertaking immune assessment is an important consideration in selecting the tests. Immune tests have been developed from several areas of primary research, including susceptibility to and recovery from specific infections, development of vaccines, study of congenitally impaired