If we grant that aging is, like other pathological conditions, a matter of molecules out of place - though perhaps considerably more complex than "simple" and singular diseases like cancer or diabetes, then we have to grant that it is also potentially subject to intervention and alteration, even reversal. We already accept this to a limited degree - age of mortality in most western societies has nearly doubled in the last century, largely as a result of better nutrition, better hygiene and better understanding and control of infectious diseases. Is it really so outrageous to extend that logic to imagine a more profound intervention against the accumulated damage of existence, which is aging? And is it crazy to imagine that this century might see the development of a suite of treatments and interventions that would achieve this?
There are some who are already entertaining the idea with active research on various avenues of life extension technology. Intervention into metabolic pathways in experimental animals, particularly fruit flies, nematode worms and mice, has been one route. These experiments have often sought to simulate the effects of calorie restriction (CR) – increased metabolic efficiency – as a means to extend life. Resveratrol, which generated a lot of buzz a couple of years ago, is believed to stimulate a class of regulatory proteins, Sirtuins, related to CR mimetics. Alternatively, in the work of Dr. Michael Rose, he and his team more than doubled the lifespan of fruit flies by postponing the age of reproduction in generation after generation. His theory is that evolution is only interested in sustaining animals to just past the age of reproduction, thereby allowing the rate of aging to be "tunable" by altering when reproduction takes place.
Perhaps the most widely known bio-gerontologist is Aubrey de Gray, Chief Science Officer at the SENS Foundation (SENS stands for Strategies for Engineered Negligible Senescence). De Gray has had wide media exposure, is in constant demand as a speaker, and has appeared in several recent books and films on longevity and the singularity. As the name of his foundation implies, his attitude to aging is not to try and alter metabolism - which he views as too impossibly complex for the foreseeable future - but rather to take an engineering approach. That is, to allow the damage of aging to happen but then to intervene to fix it before it becomes pathological. An example of this method is to introduce a microbial enzyme that breaks down the particular type of cholesterol (7-ketocholesterol or 7KC) that forms plaques on artery walls. (Fascinatingly, the method is to search through the microbes that eat the bodies buried in graveyards to find which ones eat 7KC and then discover by what enzyme it does so.) Or stem cell therapy to replace depleted or aged tissue - for instance the loss of cartilage in joints that leads to arthritis or the manufacture of replacement organs. According to de Gray there are seven major classes of aging related damage and he has proposed seven types of intervention to correct them. When will this happen? According to him it might be sooner than we think.
I think there’s a 50% chance of getting the first-generation SENS therapies working within 25-30 years. But that’s only an estimate, and it’s a highly speculative one: I think there’s at least a 10% chance that we will hit so many unforeseen problems that we won’t get there for 100 years. This is not something special about SENS, though: any technology that’s two or more years away could easily be 100 years away.
Nor is de Gray alone in thinking that true anti-aging treatments are close at hand. Dr. Rose, in the article linked above, argued in 2005 that we might be only ten or twenty years away from extending lifespan by decades. The foundation for this optimism rests upon the rapid and remarkable advancements in the field of medical and biological science in the last generation and, in particular, the last two decades. We are seeing the arrival of robotics in surgery, including testing of the first autonomous robotic surgeons; giant leaps in imaging technology such as MRIs; genomics and the beginnings of gene therapy; stem cell science and regenerative medicine; and, recently, forms of immunotherapy (basically programming the immune system to attack unwanted factors in the body - most notably cancer but also accumulations of extra-cellular junk like beta-amyloid plaques in Alzheimer's patients or arteriosclerotic plaques). And these advances only speak to the repair and/or enhancement of the body through the use of biology or medical intervention. Considerably more could be written were we to include advances in bionics - from limbs that respond to direct brain signals broadcast via implantable chips to implanted medical devices that assist - or take over - particular internal functions of the body, from insulin pumps and pacemakers to recent research on a prosthetic hippocampus to restore lost memory function.
In some of these fields the pace of advance is so dizzying that it boggles the mind to think where we were only ten years ago - and where we will be ten years from now. Consider genomics, it's been just over a decade since the first complete human genome was sequenced after fourteen year's worth of work and at a cost of around $3 billion. It now takes hours and costs $4,000 per genome. The rate of progress has been at a faster rate than Moore's Law - the famous prediction that the number of transistors that can be fit on an integrated chip doubles every two years. That doesn't mean that we've come close to figuring out the complexity of how the genome functions and the breathless predictions of the media when the first sequence was completed have failed to come to pass. But it does suggest that we are learning more, more quickly than at any time in previous human history.
And, yet, while there is some suggestion that a bright future of profoundly extended lifespans awaits those of us who live long enough - there are a lot of reasons to be rather more reserved in our optimism. For one thing it's not at all clear that the current medical model will find profit in generating the kind of tech that will ultimately lead to longer lives. Nor is it necessarily the case that even if a cure were created that it would be accessible to everyone or even a majority. And what if lifespans are radically extended - how will that effect the population, planetary resources and, ultimately, how we live our lives? Do we want to live a thousand years working crappy, meaningless jobs? In this series I want to look at some of these issues.
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