(Crossposted from Depressed Metabolism)

Just a superficial look at the history of the life extension movement will suffice  to show the rise and fall of numerous fads and trends in ideas about the mechanisms and “treatment” of aging.  Psychological meliorism and simplistic visions of biochemistry create overly optimistic expectations about extending the maximum human lifespan.  But how can we know if a treatment is able to extend the maximum lifespan of humans without giving it to them and waiting….

In his article “Why Cryonics Will Probably Help You More Than Antiaging” (2004), cryonics activist Thomas Donaldson contrasts cryonics with antiaging as a means to life extension and argues that a major advantage of cryonics is that cryobiology research can move at a much faster pace than anti-aging research, especially as it pertains to humans:

The best possible proof that a treatment will indefinitely prolong the lives of human beings must come from a demonstration of its effects on human beings. Not fruit flies, worms, mice, or rats, but human beings. Yet there’s a small problem here: we are human beings ourselves, and a proof that a treatment prolongs the lifespan of people will take … at least the lifespan of some people…cryobiology can progress much faster than antiaging. Not only that, but its progress almost totally lacks the problems of proving that an advance has happened. The state of a brain, or even a section of brain, after vitrification and rewarming to normal temperature, shows directly whether or not the method used improved on previous methods.

What about treatments that have been shown to extend the maximum lifespan in small mammals? Or using  treatments that have been shown in humans to stop or slow down the aging process?

“It takes a long time and the actual reports on clinical use of a drug for physicians to get an idea of the effects of longterm use of that drug.  Very few drugs of any kind get formal tests for the entire lifespan of normal people taking them.”

Even if people are not prevented from experimenting with various life extension technologies, these epistemological and practical problems cannot easily be overcome.

“No matter what some scientists say, a cure for aging involves many problems all of which will need time for their solution. Even now, you may be young and feel that you need not think about cryonics because some means to slow your aging will come before you’ve gotten very old, and from that still other means to slow your aging even more … and so to true agelessness. In this article we have seen why such dreams of a rapid solution to aging cannot come fast for any of us. At the same time, cryonic suspension able at least to preserve our brains in a reversible form, allowing restoration of vital functions, looks likely to come much sooner.”

And as Robert Prehoda pointed out in an old interview, successful treatment of aging will still leave an individual vulnerable to accidents:

Immortality is statistically impossible because accidents would eventually eliminate all individuals in any non-aging population.

Despite these arguments, the life extension and “transhumanist” movement remains many times larger than the people who have made cryonics arrangements.  Some reasons for this are explored in another entry, but the mystery remains.