Abstract
Infection is the major cause of health impairment in elderly persons. Immune function declines with age. In order to keep the elderly in good health, it is necessary to control the age-associated decline of their immune function. Components of a non-specific immune system arc neutrophils, macrophages and NK cells. A specific immune system is composed of T lymphocytes and B lymphocytes. T lymphocytes differentiate in the thymus. Age-associated atrophy of the thymus causes a decline in T lymphocyte function. It is essential in aging of the immune system. B lymphocytes produce immunoglobulin to act as antibodies. With aging, abnormal antibodies such as autoantibodies and monoclonal immunoglobulin increase, and the number of normal antibodies compared to foreign antigens decrease. Exercise influences the autonomic nervous system, hypothalamo-hypophyseal system, and immune system. Moderate exercise enhances immune function, and severe exercise causes immune function decline. Immune function declines after a severe single bout of exercise, and an “open window” of infections occurs. Appropriate exercise training may improve immune function. Recently, it was shown that exercise training for one year increased the contents of secretory immunoglobulin A in saliva in elderly persons. This result suggests that long-term exercise training improves immune function in elderly persons.
