Anti-aging studies, when they make the news, fall into three unequal categories. There's a vast pile of quackery, which mercifully isn't (for the most part) newsworthy. There are studies whose conclusions are misinterpreted by some reporters, or overblown by one party or another. And there's a small cohort of really interesting stuff.
Yesterday's news in the field very much looks like it belongs in that last set. Two papers (here and here) came out early in Science that result from long-running research programs on what happens when young mice and old mice have their circulatory systems joined together, coming from the labs of Amy Wagers and Richard Lee at Brigham and Women's Hospital in Boston, and Lee Rubin's group at Harvard. Wagers herself started on this work as a postdoc at Stanford almost fifteen years ago, and she clearly hit on a project with some real staying power. A third new paper in Nature Medicine, from Tony Wyss-Coray's group at Stanford, also bears on the same topic (see below).
The aged rodents seem to benefit from exposure to substances in the youthful blood, and one of these seems to be a protein called GDF11. Wagers and Lee had already reported that administering this protein alone can ameliorate age-related changes in rodent heart muscle, and these latest papers extend the effects to skeletal muscle (both baseline performance and recovery from injury) and to brain function (specifically olfactory sensing and processing, which mice put a lot of effort into).
So the natural thought is to give aging humans the homolog of GDF11 and see what happens, and it wouldn't surprise me if someone in Boston ponies up the money to try it. You might need a lot of protein, though, and there's no telling how often you'd need infusions of it, but to roll back aging people would presumably put up with quite a bit of inconvenience. Another approach, which is also being pursued, is the dig-into-the-biology route, in an attempt to figure out what GDF11's signaling pathways are and which ones are important for the anti-aging effects. That's when the medicinal chemists will look up from the bench, because there might be some small-molecule targets in there.
That's going to be a long process, though, most likely. GDF11 seems to have a lot of different functions. Interestingly, it's actually known as an inhibitor of neurogenesis, which might be a quick illustration of how much we don't know about it and its roles. It would seem very worthwhile to try to sort these things out, but there are a lot of worthwhile biochemical pathways whose sorting-out is taking a while.
The Wyss-Coray paper goes in the other direction, though. Building on earlier work of their own, they've seen beneficial effects on the hippocampus of older mice after the circulatory connection with younger animals, but were able to reproduce a fair amount of that by just injecting younger blood plasma itself. This makes you wonder if the "teenage transfusion" route might a much more simple way to go - simple enough, in fact, that I'm willing to put down money on the possibility of some experimentally-minded older types trying it out on their own very shortly. Wyss-Coray is apparently planning a clinical trial as we speak, having formed a company called Alkahest for just that purpose. Since blood plasma is given uncounted thousands of times a day in every medical center in the country, this route should have a pretty easy time of it from the FDA. But I'd guess that Alkahest is still going to have to identify specific aging-related disease states for its trials, because aging, just by itself, has no regulatory framework for treatment, since it's not considered a disease per se. The FDA has consistently avoided going into making-normal-people-better territory, not that I can blame them, but they may not be able to dodge the question forever. At least, I hope they won't be able to. You also have to wonder what something like this would do to the current model of blood donation and banking, if it turns out that plasma from an 18-year-old is worth a great deal more than plasma from a fifty-year-old. I hope that the folks at the Red Cross are keeping up with the literature.
Irreverent aside: (Countess Báthory, an apparent pioneer in this field whose dosing protocols were suboptimal, does not seem to be cited in any of the press reports I've seen. Not sure about her publication record, though - maybe she's hard to reference from the primary literature.