Is it strange and unexpected that attempted life-extending drugs shorten lifespans as often as they increase them?
The activities of people like Ray Kurzweil, who take literally hundreds of supplements, suggest that this is strange and unexpected, and cannot be deprecated enough. It also particularly cautions us against caring about any supplement or drug without dozens of positive studies (at a minimum).
Or is it disturbing that the drugs are very likely to simply do nothing at all?
That's also disturbing. It suggests - pace Algernon's law - that there is no good simple intervention.
The fact that this is a pretty smooth bellcurve also indicates, as far as I can tell, the general field has found no intervention at all that works - because then there would be dozens or hundreds of studies tweaking it and replicating it and investigating why it works. We don't see a bimodal hump with most interventions at net 0%, and a second bell curve of caloric restriction/intermittent fasting centered at eg. +40%.
(This latter interpretation could be wrong, since the data is so heterogenous. It could be that the apparent excess of studies around +100% represent many of the CR/IF studies.)
I don't understand what you're trying to say:
suggest that this is strange and unexpected, and cannot be deprecated enough.
Previous:
From the excellent Fight Aging! blog comes a pointer to "A Histogram of Results from Life Span Studies", a graph of thousands of animal studies by Kingsley G. Morse Jr. (updated version from mailing list):
(This is not the same as a funnel plot, as the y-axis is # of studies finding that percentage gain and nothing to do with the n of studies.)
On the closed GRG mailing list, the compiler says:
I asked some questions, and Steven B. Harris replied:
The relevance of this summary graph to news like the C60 rodent life extension experiment is obvious. Reading GRG has been interesting and educational about that experiment; a rough summary of points made by various people including myself: