Skulachev's group published a paper last year that looks at the effects of mitochondrially targeted antioxidants on the lifespan of rodents. Their compounds are structurally similar to the adduct formed from C60 reacting with the fatty acids in olive oil, and all the effects of c60-oo are consistent with it being a mitochondrially targeted antioxidant. Skulachev's group has seen evidence that the enhancement of lifespan caused by their compounds are only seen when started early in life:
The unusual biphasic shape of the survival curves of mole-voles (Figure7) should be discussed in more detail. We suggest that the reason for this is that some animals received SkQ1 at a younger age than others. This seemed to be quite likely since among the mole-voles caught in the Siberian taiga were animals of various ages. As previously shown in our group [3, 4], one week-long SkQ1 treatment prolonged the lifespan of Drosophila if the treatment was carried out during the first week of life, but it was ineffective when given for the same period in the middle of life. Assuming SkQ1 is an inhibitor of the execution of the aging program, we speculate that it fails to induce a strong increase in lifespan of mice since the SkQ1-treated animals die, after all, as a result of cancer. If cancer is a very rare reason for death of mole-voles, a large increase in the lifespan by SkQ1 becomes possible. This possibility was confirmed when post mortem estimation of age of dead mole-voles was carried out. All the SkQ1-treated animals who died during first two years in captivity started to receive the antioxidant since the 2nd year of the life (Figures 7C,D).
The theoretical underpinning of this effect was eloquently described by Reason on his blog, Fight Aging. It is definitely worth a read.
A particular consequence of this effect might show up in AgeVivo's mouse experiment. He started c60-oo treatment on three middle-aged mice, one of which recently died from a tumor.
There are a number of reasons to believe that mitochondrial antioxidants will provide health benefits even if started late in life; see for example this post, not to mention the numerous reports we've had from people here.