Against the "extend healthspan but not lifespan" cliché.

What is the ultimate goal of biogerontology (the study of the biology of aging)? A fashionable answer these days, often encountered, is that it is to extend healthspan not lifespan. Here we argue that this is a misguided cliché. Experimental research with animal models has demonstrated the possibility of intervening in and retarding the aging process, and extending lifespan. This, to varying degrees, increases both healthspan and gerospan, the later-life phase in diminished health. Considering possible equivalent interventions in human aging it would of course be desirable to maximize the former and minimize the latter. However, should a given intervention extend gerospan, given that it would postpone death (i.e., save lives) it would, in many circumstances, be unethical to withhold it. Life in moderately diminished health is generally preferable to death, and this is reflected in the recognized value of many life-saving medical interventions that do not restore full health. Thus, "extending healthspan but not lifespan" is not a coherent objective for research on aging.