Healthspan, Not Lifespan
In this paper the author looks ar the oucomes of past efforts to modestly extend life, mostly in the laboratory only, via the traditional drug discovery and development process, or pharmacology. I'd argue that any debate over targeting lifespan versus healthspan is an artifact of focusing on strategies that can do very little in the grand scheme of things, either slightly slowing aging or slightly compensating for one or more aspects of aging without addressing its causes. Only in this realm is it possible to produce therapies that could extend life without extending health to match. It becomes moot for true rejuvenation therapies that repair the underlying cell and tissue damage that causes aging, and are capable in principle of extending life by decades if made effective enough at that repair. At that scale of life extension, and by that methodology of damage repair, healthspan and lifespan are extended in tandem - it isn't possibly to move one independently of the other. Present damage determines both current health and future trajectory of health and mortality absent future repair.
The main goal of this paper is to present the case for shifting the focus of research on aging and anti-aging from lifespan pharmacology to what I like to call healthspan pharmacology, in which the desired outcome is the extension of healthy years of life rather than lifespan alone. Lifespan could be influenced by both genetic and epigenetic factors but a long lifespan may not be a good indicator of an optimal healthspan. Without improving healthspan, prolonging longevity would have enormous negative socioeconomic outcomes for humans. The goal of aging and anti-aging research should therefore be to add healthy years to life and not to merely increase the chronological age.This paper summarizes and compares two categories of pharmacologically induced lifespan extension studies in animal model systems from the last two decades: those reporting the effects of pharmacological interventions on lifespan extension alone, versus others that include their effects on both lifespan and healthspan in the analysis. The conclusion is that the extrapolation of pharmacological results from animal studies to humans is likely to be more relevant when both lifespan and healthspan extension properties of the pharmacological intervention are taken into account.
I do think healthspan should be somewhat of a focus... after all, who would want to be 120 in a state of decline like you experience from 80+ or so. And increasing healthspan should increase lifespan too (hopefully more than the 2.5 years the people behind the metformin trial propose though). I think talking about the benefits of "healthspan" could get some of the people who are indecisive, or against longevity on our side though. It seems like that concept is easier to warm up to.
@Ham
Hi Ham !
I agree with you, we have to sell healthspan to the mass because they don't buy into the immortal band wagon, they want something concrete (clinical trial results - tested on humans), realistic (you will gain 10 years disease free - guaranteed or we pay you your impromptu medical insurance bills in damage compensation), not outlandish (radical longevity extension beyond 122 years maximum human lifespan and speak of Centuries Lifespan). Anything remotely extreme sounding falls in fringe quack, the level of suspicion is extreme these days for some snake oil sellers want to make cash from new era of biogerontology, with false promises of living eternally. The level of pessimism is higher than optimism (auto-defense guard mechanism to not get played/fooled by crooks (Charlatanism) when talking more extreme biorejuvenation stuff). It's like big scientific jargon to people, but they can see through lies, schemes and false empty promises. There is an old French saying here : " Chat échaudé. Chat échaudé pour toujours. " (Cat burnt. Cat burnt forever).
I think, it is only normal to focus on healthspan, the time disease free with great health, that would extend the Average Median Longevity possibility up the Maximum Human Longevity (122 years).
But as Reason suggested, Health span goes hand in hand with Average Lifespan and Maximum Lifespan. Meaning they are interlinked together, you obviously need to stay healthy longer (avoid morbidity disease pathologies) to have a longer average lifespan and perhaps reach the Maximum Human Lifespan; if genetically ultra-lucky.
I don't think it's an admitance of defeat/capitulation, that we must focus on healthspan or that humans will never surpass their biological Maximum Lifespan limit of 122 years. It's reprioritizing shift towards better health/quality of life in the short term for the Urgent Ones (the Elders seniors and soon dead of today and the near tomorrow, who suffer debilitating diseases in silence or screaming agony, depending).
In my POV, biorejuvenation is not there yet but making great strides, we will have to be maintained biorejuvenated to exceed Maximum Human Lifespan and skyrocket stratosphere, through New Heights - Serious Sh... Not Crap, but Real Tangible Scientifically Grounded Future. Radical Centuries Lifespans, No BS. Oblivion is Next. Let's be Optimistic for sake, but exercise Prudence.