While the term aging can apply to changes occurring during any phase of life, dysfunctional aging (or senescence) refers to changes associated with accelerated morbidity and mortality rates during the latter phase of adult life. Biomedical studies on the disorders of senescence include not only specific disease states but also conditions not easily classified. Basic biomedical science can substantially improve the quality of life for older persons, and add to the list of social and medical advances in which the nation takes pride, advances that eliminated so many of the killing and crippling diseases of childhood and younger adults.
A number of puzzling questions about aging have attracted the interest of biomedical researchers. Why do humans differ so individually in aging changes of bone, brain, and heart? What preconditions for aging may be set earlier in life, perhaps even in utero? What is the role of gene-environmental interactions in the individual patterns of aging? The committee believes that understanding these processes will lead to interventions that may delay or even reverse disability.
Although many fundamental processes of aging are yet to be understood, progress already has been made in distinguishing between the process of natural aging and disease states associated with older age. Achieving further knowledge will require contributions from genetics, biochemistry, cell biology, neurobiology, and other disciplines. Equally important is the integration of aging research with other areas of investigation that historically have focused on specific organs and diseases without considering the surrounding manifold of aging changes. The committee emphasizes that many major advances in science have been unanticipated. Therefore, it is essential to maintain the traditional primacy of investigator-initiated studies—the source of many research breakthroughs.
Recent advances in the basic biomedical study of aging will contribute significantly to the foundation for future progress in the understanding of how individuals age. Among these achievements are insights into gene regulation and other basic cellular functions; the development of colonies of rats that have shown increased lifespan and delayed decline of function following food restriction; and the creation of strains of mice with targeted mutations (i.e., basic changes in the genetic blueprint for proteins) that will improve understanding of the processes of aging.
Major conceptual and methodological successes in molecular biol-