Nutritional Countermeasures to Immune Dysfunction

Upper respiratory tract infections (URTIs; e.g., coughs and colds, throat infections, and middle ear infections) are a leading cause of visits to general practitioners throughout the world. Although regular moderate amounts of exercise may slightly reduce the risk of contracting one of these infections compared with sedentary lifestyles, athletes involved in intensive training programs, and in particular those involved in endurance events, are apparently more likely to contract URTI than the [Page 790]general population. A major factor in this relationship appears to be the effect of intensive training stress on the functioning of the body's immune system. Immune functions are largely impaired by stress, be it physical, psychological, or environmental, or by improper nutrition. An accumulation of stress can lead to chronically suppressed immune function, ...