I'd missed the emergence of the latest issue of Rejuvenation Research last month, which opens with this:
Possibly the biggest battle that I have had to fight over the past decade is to persuade people to take seriously the idea that it is time even to think about "reversing aging" while we remain so negligibly able even to slow aging down. The flaw in that logic is simple: it is that rejuvenation, i.e. the restoration of an organism's physiological state to how it was at an earlier age, will be achieved not by reversing the processes of aging but by repairing the accumulated damage that those processes create. To get back to where we came from, in other words, we do not need to retrace the route we took from there to here. Any route will do, and in this case there turns out to be a vastly more plausible route than the retracing one.
The debate over the the large-scale course of longevity science, focusing on either repair of aging (thus effectively reversing its effects) or slowing aging through re-engineering human metabolism, will determine how long we all live.
It is likely to be easier and less costly to produce rejuvenation therapies than to produce a reliable and significant slowing of aging. A rejuvenation therapy doesn't require a whole new metabolism to be engineered, tested, and understood - it requires that we revert clearly identified changes to return to a metabolic model that we know works, as it's used by a few billion young people already. Those rejuvenation therapies will be far more effective than slowing aging in terms of additional years gained, since you can keep coming back to use them again and again. They will also help the aged, who are not helped at all by a therapy that merely slows aging.
Whatever the course of research, the first resulting widespread therapies to significantly extend healthy human life are two or more decades away. Most of us will be old before the second generation of better and more reliable therapies emerges thereafter. Thus repair strategies for ongoing research must come to dominate the funding landscape over the next decade if we are to see meaningful progress in engineered human longevity within our lifetimes. Slowing aging will be of little use to us by the time it becomes available.
All of this means that this scientific debate is far too important for all of us to refrain from participation. We should all absolutely dive in and loudly offer our own opinions on the topic, and help the researchers and fundraisers focused on repair biotechnologies succeed in their aims: it is, after all, the future of all our lives on the line.