Trace metals, aging, and immunity

Dietary deficiency of trace metals among human populations, once thought to be exceedingly rare, has recently gained attention as a potential public health problem. The consumption of highly refined and heavily processed foods reduces the trace element content of the diet. The higher trace element requirements during pregnancy, lactation, growth, development, and chronic disease may further contribute to states of marginal trace metal nutriture. Experimental animal studies have demonstrated that even marginal trace element deprivation during critical periods of growth and development or, alternatively, during prolonged deficiency in adults can significantly alter immunologic function Furthermore, trace metal nutriture has been shown to affect the initiation and progression of a large variety of neoplasia. These observations are of major significance to the aged and suggest the need to vigorously define the trace metal status and its relationship to immunity in this nutritionally at-risk population.