## Herding experts

Experts can come in for a lot of criticism, but they have their uses. After all, with no heads above those parapets, humanity would neither see so far nor have enough target practice. Anyway, I recently took the opportunity to catch up on expert opinion at a debate on ageing at the Edinburgh Science Festival. It pitted Dr Aubrey de Grey, founder of the SENS Research Foundation active in the area of regenerative medicine, against Professor Richard Faragher, specialist in accelerated ageing disorders. The event painted an interesting picture of the diversity of views in the biomedical longevity research field today.

Although both broadly agreed on a definition of ageing as the accumulation of damage arising from metabolism, they differed markedly in their research approach. De Grey characterised his work as being applied science rather than pure research, believing it a fool's errand to attempt to unravel the complex connections between metabolic processes by which damage accrues — instead his aim is to develop technologies to repair the damage itself. Faragher on the other hand felt that while the science now points to a relatively small number of causal mechanisms for ageing, we should endeavour to fully understand those mechanisms.

Acknowledging lack of funding as a common problem across scientific research, both speakers nevertheless felt it particularly applied in biogerontology. De Grey laid some responsibility for this at the door of the scientific establishment, for refusing to accept the battle is with ageing itself, rather than the diseases that arise from it. Since clinical trials only receive regulatory approval when targeting a recognised disease, this is a more than philosophical point for SENS, which seeks to repair ageing damage before it accumulates into pathology.

Timescales for progress in novel research areas are devilishly hard to predict, as barriers can be cultural as much as scientific. De Grey is keen on timescales however, and sees benefit in articulating clear, specific and measurable targets, something he finds too rarely in the output from other researchers. With appropriate funding he foresees a 50% chance of adding 30 years onto human lifespan in the next two to three decades. Faragher on the other hand highlighted Magnus Pyke's prediction in 1980 that trains ought to be travelling at 20,000 kilometres-per-hour by now. He stated that while scientific experts were often proved wrong (citing the once widely held oxidative stress theory of ageing as an example), visionaries, with a nod towards de Grey, took the risk of being wrong to another level entirely.

Faragher represented his interests as more near-term, highlighting the value of further investigation into existing compounds such as Resveratrol, Metformin and Rapamycin, since these may trigger internal recycle-and-repair mechanisms that are known to be stimulated presently via caloric restriction. The impression was given that caloric restriction was, if you'll pardon the pun, small potatoes to Aubrey de Grey. He stated his belief that the associated gains reduce with species lifespan — so whilst we can triple the life span of a worm, we might add 40% for a rat, 10% to the life of a dog and at best one or two years in a human.

So two researchers, both speaking for the likelihood of continuing mortality improvements, but one with a focus on short- to medium-term research into exploiting and retarding natural processes to ameliorate disease, and the other with a focus on repairing or removing all classes of ageing damage found in the body. De Grey stated that his kind of research would never be funded by the traditional pharmaceutical industries. Given his objective to eliminate death by ageing altogether, I can't help but feel it wouldn't be sponsored by many annuity providers either!

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