Radical life extension is a term showing its years these days: it sounds so very 90s. It can be applied to any goal of adding decades or centuries to healthy human life spans, though as Aubrey de Grey pointed out more than ten years ago in this environment of progress in biotechnology there is little difference between adding a few decades and adding a few centuries. A very binary divide lies ahead of us: either you live long enough to see medical science start to add additional years of life faster than aging can take it away, or you don't. If you do, then your life span is thereafter only bounded by accidents, which given present mortality rates means you will probably live for a thousand years or so, in excellent health and with a youthful physique periodically repaired by ever more advanced therapies.
At present life expectancy for older adults is increasing at perhaps a year every decade, but this is entirely accidental, a side-effect of growing wealth and improvements in medicine. To a first approximation no-one has been trying all that hard to intervene in the aging process: all of the real effort has gone to trying to clean up the consequences, a task that is ultimately futile if you never deal with the root causes. In the years ahead this state of affairs will change, and since there is usually a big difference in outcomes between trying and not trying, we'll no doubt see a great upward discontinuity in the trend of life expectancy as a result. When researchers are actively trying to treat aging as a medical condition, then there will be an appropriate level progress.
The real question is how soon will the fruits of this labor arrive? Trying to spur more rapid progress, and thus a greater likelihood of effective treatments developed before we age to death ourselves, is why there must be advocacy and fundraising. It is why there must be disruption in aging research in which inefficient lines of research are replaced with better ones. The status quo of the recent past is about to be replaced with a new set of research projects for the decades ahead, and if those of us in middle age now want a shot at rejuvenation treatments, then this next crop of research strategies had better be good ones. We have every motivation to help out and fund the research we think best.
Science must be accompanied by advocacy, as at the large scale the only research to receive significant funding is that with widespread public support. Think of the cancer research community and the attitudes of the average fellow in the street with regard to curing cancer. We still stand a long way removed from that sort of support for eliminating all age-related disease and greatly extending healthy life. The public is somewhere between indifferent, hostile, and confused with regard to life extension. People support research on well-known diseases that are caused by aging, but at the same oppose work on greater longevity or eliminating aging, and yet are fearful and saddened by the costs of growing old and that deaths and suffering of those around them.
Still, the past decade of advocacy has led to great changes in attitudes in the research community and in segments of the public. This continues. There is a steady evaporation of skepticism with regard to radical life extension, accelerating of late with the advent of several large and public initiatives in aging research. Where the writers and the speakers go, so too will others follow in the fullness of time:
The Treasurer of Australia, the Hon Joe Hockey MP, recently received widespread attention with the statement: "It's kind of remarkable that somewhere in the world today, it's highly probable that a child has been born who will live to be 150." Hockey made the claim while discussing some of the problems Australia faces as a result of an ageing population. While his statement was ridiculed by cartoonists and political rivals, he received support from some in the medical community. The Dean of Medicine at the University of New South Wales, Peter Smith, described Mr Hockey's claim as a "reasonable assumption". Professor Smith noted that life expectancy for Australians has been climbing dramatically over the past 100 years.
Scientists have long been able to manipulate ageing in other animals. However it has so far proved much harder to extend the lifespan of our own species. Humans have already evolved to have a long lifespan, due mainly to an unusually long post-reproductive phase of life. The same mechanisms used to increase lifespan in short-lived species have little impact on human lifespan, or that of other primates. Hence the fact that we can extend the lifespan of other animals only partially supports the claim that we will soon be able to manipulate human ageing and extend lifespan to 150 years. Significant research effort will be required to reach this milestone.
The most significant consideration favouring lifespans of 150 in the near future term, then, is the fact that there is now a lot of interest in life extension research, both within academia and from well-funded corporations. In late 2013 one of the world's largest companies, Google, established a subsidiary called Calico, with the sole focus of investigating ways to combat human ageing. Similarly Craig Venter, whose company Celera Genomics was the first to sequence the human genome, recently established Human Longevity Inc, a new company with a focus on enhancing human lifespan. One research direction these companies are likely to explore involves incorporating nanotechnologies into our cells. Many gerontologists believe that ageing consists solely of a small number of cellular changes, which are potentially preventable and reversible. Once we develop technologies capable of preventing and reversing these changes, we can prevent and reverse ageing.