It serves as a reminder that the research community actually knows very little about the demographics of aging at very advanced age. The data is so sparse past age 110 that the statistics of mortality, very reliable in earlier old age, rapidly turn into a sludge of uncertainty. It is possible at this point in time to argue either side of the position that there is or is not a limit to longevity under present circumstances, though most of us probably think that one or the other side is weak. On the one hand we can theorize that maximum human life span is increasing, in a way analogous to the fact that life expectancy at 60 is inching upward at a year every decade, but more slowly, and we might suggest the data for extreme old age is so bad that the ongoing change can't be identified. On the other hand we can instead theorize that there is some limiting process that hasn't changed at all over the course of recent human history, is not impacted meaningfully by modern medicine, plays a very large role in supercentenarians in comparison to younger old people, and renders mortality rates so very high at the extremes of human life spans as to form a limit.

This is actually a point worth making twice: when limits to lifespan are discussed, we're not talking about actual limits per se, but effective limits. A very large mortality rate, possibly coupled with rapid growth in mortality rate over time, looks a lot like a hard barrier to further progress in practice, but there is still the chance that someone could beat the odds. Where the data for supercentenarians is good enough to fill in tentative mortality rates with large error bars, up to age 115, that rate is around 50% annually [1]. The mortality rate may increase greatly after that point, and that would be entirely expected given the absence of more than the one certified example making it past 120, but it is very unclear from the limited data. Mortality rates reflect actual physical processes, the accumulation of forms of cell and tissue damage that cause the suffering, death, and disease of old age. The damage is the same, but the proximate causes of death for supercentenarians are quite differently distributed from those of younger old people, prior to a century of age. The majority appear to be killed by transthyretin amyloidosis [2] that clogs up the cardiovascular system, and that is becoming known to play a much lesser - but still significant role - in heart disease in earlier old age. Could this form of amyloidosis be the candidate for a process that is not all that affected by the past century of changes in medicine and lifestyle, and that becomes much more important in extreme old age than early old age? Possibly. The only way to know for sure is to build ways to clear this form of amyloid [3] and see what happens.

The natural state of aging is a function of damage and how medicine addresses that damage - which is poorly and next to not at all at the present time. Almost all medicine for age-related conditions fails to address their root causes, the cell and tissue damage of aging [4], and takes the form of patching over that damage in some way or coaxing biological machinery to cope slightly better with running in a damaged environment. Predictably it is expensive and only marginally effective in comparison to true repair. As above in the comments on amyloidosis, find a way to repair that problem and life span will increase, as the machinery of biology will be less damaged and less worn down into high rates of failure. That is the point to take away from this discussion. It has to be said that the lead of the study, Jan Vijg, comes across as very pessimistic on aging in his comments here when considered in comparison to past remarks and collaborations with SENS folk [5] that I've seen from him. That is the case even granting that he is in the camp of researchers who believe there is no alternative to a very slow and expensive reengineering of human metabolism in order make incremental gains in life span and slowing of the aging process.

[1]: http://dx.doi.org/10.1007/978-3-642-11520-2

[2]: http://dailybruin.com/2010/03/04/autopsy-115-year-old-aids-r...

[3]: http://www.uclb.com/news-and-events/news-post/potential-new-...

[4]: http://www.sens.org/research/introduction-to-sens-research

[5]: http://dx.doi.org/10.1159/000357670