It should be emphasized that back-of-the-envelope calculations, such as the one given in this post, ought to be adjusted to account for the fact that interventions can look much more cost-effective than they are, especially when the interventions were only shallowly investigated.
Previously, Givewell has looked into the cost-effectiveness of life sciences funding, as well as publishing a simple estimate of the impact of the average dollar spent on cancer research, which suggested that, in the past, each $2790 spent on cancer-relevant biomedical research in the US added one year of life lived (YLL) to the life of a US resident. Givewell has also interviewed Aubrey de Grey of the SENS foundation. Owencb has previously estimated the cost-effectiveness of funding SENS/ anti-aging research as being around $50 per QALY. Aubrey de Grey has previously been averse to giving explicit cost-effectiveness estimates regarding how many QALYs would be gained per unit of funding supplied to SENS, though he has been clear that SENS's funding needs are "$100 million per year for each of the next ten years".
This part of the post will consist of me using lots of best guesses to produce something vaguely resembling a cost-effectiveness estimate for SENS. You should not take this cost-effectiveness estimate literally.
If SENS needs one billion dollars to ensure that rejuvenation technologies that give individuals 30 extra years of healthy life are available to the public in 30 years, we might (completely arbitrarily) assume that someone else will come along and fund SENS in ten years if we don't contribute to funding SENS today. This means that if we fund SENS today instead waiting for it to be hypothetically funded in ten years from now, about ten times the number of people who die each year would live 30 years of healthy life that they wouldn't have lived otherwise. Given that there are about 57 million deaths per year worldwide, this translates to about 17 billion YLLs lost by waiting ten years to fund SENS; since SENS ostensibly requires only 1 billion of philanthropic funding, this implies that $0.059 of funding for SENS produces a YLL.
Of course, regenerative medicine won't be free to the people receiving it, and I have no idea how to account for this, given that I don't have a good idea of how much regenerative therapies will initially cost. The above estimate hasn't been adjusted to account for the fact that there is a time-delay between when funding is provided, and when the benefits of regenerative therapies are available to the public. Perhaps Aubrey isn't well-calibrated, and the "$100 million per year for ten years" figure is entirely wrong. It may be the case that starting work on SENS's research agenda earlier rather than later would allow certain people who would have otherwise died to live until aging escape velocity is reached, which would have lots of utility. There are plenty of other issues with this cost-effectiveness estimate which I am sure that readers could point out.
The point I wanted to make, though, was that maybe, possibly, SENS is competitive with GiveWell's top charities-- I'm legitimately not sure whether I would fund SENS or GiveWell if I were making a charitable donation today. Does anyone have any further thoughts on this topic?
'Ironing out' is an understatement... how the heck do you get fingernail stem cells into the right spots and replenish every hair follicle? Bone marrow is easy, those cells move through the blood and colonize their proper niches when they flow through the bone. But solid tissue, with immobilized cells and extracellular matrix?
Oh hell yes. The animal mitochondrion is a crazy jerry-rigged mess with a genome more overoptimized than many viruses, bizarre specialized ribososomes specifically optimized for making the handful of proteins that the mitochondrial genome codes for while at the same time being obviously slapped together from spare parts, RNA-editing that sometimes is unclear what is important and what is noise, and some of the genes may need to be in the mitochondrion for the purpose of real-time regulation. And the same core set of genes coding for large, hydrophobic, membrane-bound proteins have failed to move into the nuclear genome in all branches of life because that stuff is damn hard to get through two membranes without having it congeal into pellets of inert goo. I've seen interesting work of late involving trying to get RNA-channels embedded in mitochondrial membranes to allow cytosolic RNAs with the proper signal sequences to get into the mitochondrion to be translated there, with some success, but I have little reason to think that such a system would improve upon normal mitochondrial function because poking a complicated system will often just make it worse. This is not to say that mitochondria are perfect, you can imagine in five seconds about twenty ways to make them better than they are - none of which are things you can do by simply going in and making a few simple mods to an existing eukaryotic system.
On another note it is pretty well impossible to get in and modify large fractions of cells in a living organism as opposed to a monolayer of cells in a controlled environment in a laboratory. This being said, I think one of the most fruitful avenues for actual anti-aging research would be looking for ways to chemically boost protein chaperone/recycling activity and improve the regulatory interactions between mitochondria and the cytosol.
"because poking a complicated system will often just make it worse."
yeah that was my view. I have only an amateur interest in biology though.