Biological aging research today: potential, peeves, and problems.

Aging research has benefited immensely from the application of genetics during the past decade. This success frequently obscures some of the latent difficulties associated with this method. Interpretations of many experiments are overly optimistic. The emerging functional methods spawned by the knowledge of the genome promise a new window on the biological aging process. However, conceptual approaches have not quite caught up with the technology. An integrative approach to aging is needed, based on systems biology, to tap into this technology and to provide a deeper understanding of the operation of this complex process. The profound quantitative changes inherent in such phenomena as caloric restriction may actually result in stark qualitative changes in metabolism and aging. The ultimate goal is to understand the aging of the individual, and not simply to describe the mortality trajectories of the population. However, this will require the development of indices of frailty and of healthy aging. In the end, we may be able to 'cure' aging, but only in a statistical sense which is measured at the level of the population.