Nutrition and immunity.

Severe protein deficiencies such as kwashiorkor result in immunosuppression of humoral cellular and mucosal immune systems. These suppressions result in a greater incidence of disease in animals and humans and create increased risks of morbidity and mortality due to infectious disease or neoplasias. The effect of moderate protein-calorie deficiency on immuno-competence appears to be highly variable in studies with experimental animals. In young animals, some parts of the host-defense systems are stimulated while other are inhibited. These effects appear to result in long life-spans. This may be due to slower maturation and, hence, a slower decline of host-defense systems in the moderately malnourished animals.