Is programmed aging a cause for optimism?

Abstract

Aging is now viewed as programmed under genetic control by a growing minority of evolutionary biologists, and a larger proportion of researchers in gerontology. The hypothesis of programmed aging has been regarded as encouraging for anti-aging science. Some mechanisms of programmed aging may present ready targets for medical interference [mitigation alleviation attenuation], while other kinds of programmed mechanism may yet prove to be refractory. The most promising possibility is that the machinery responsible for maintenance of the vibrant and youthful state of the body is never really lost, but de-commissioned by hormonal signals in the aging body; restoring a youthful signaling environment should then be sufficient to prompt the body to restore itself. But it is also possible that aging may be programmed in a way that does not facilitate anti-aging interventions. We identify two possible cases: In the first, the body is programmed to age via neglect rather than by affirmative self-destruction, so that damage is accumulating that the body is beyond the body's power to repair. In the second, aging is controlled by an epigenetic clock whose workings are so intricate as to be intractable for human mastery in the foreseeable future. There is substantial evidence that first of these is not a likely scenario, but the jury is still out on the second.