The Youth Pill: Scientists at the Brink of an Anti-Aging Revolution”, by David Stipp (www.davidstipp.com)." data-pin-do="buttonBookmark">
Adapted from “The Youth Pill: Scientists at the Brink of an Anti-Aging Revolution”, by David Stipp (www.davidstipp.com).
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Editor's note: This article is adapted from the book The Youth Pill: Scientists at the Brink of an Anti-Aging Revolution, by David Stipp. We are presenting it in conjunction with Stipp's article "A New Path to Longevity" in the January 2012 issue of Scientific American. Additional information can be found in "What Unusually Long-Lived Animals Say about Human Aging."
The study of aging tends to raise the kind of deceptively simple questions children ask, such as, “Why did Spot, who was the same age as me, get old and die before I grew up?” Such queries quickly lead to deep mysteries, none of which are more riveting than those surrounding extraordinarily long-lived species.
One that has come to the fore in recent years is a grotesque, mouse-sized rodent called the naked mole-rat. Resembling saber-toothed sausages, they’re even weirder than they look. For one thing, they live in termite-like, underground colonies populated by workers that serve as a support system for a single breeding queen. But their most mind-bending trait is an incredibly slow rate of aging. In captivity they can reach about 30 years of age, ten times the typical life spans of their mouse cousins. To see how remarkable that is, imagine a species of primates with a life span of a thousand years.
The leading authority on mole-rat longevity is Rochelle Buffenstein, a researcher who maintains a sizable colony of the animals at the Barshop Institute for Longevity and Aging Studies, part of the University of Texas Health Science Center at San Antonio. When I visited her one afternoon, she led me to a dimly lit room where I found myself surrounded by scores of chirping mole-rats merrily tending their nests inside clusters of shoebox-sized containers connected by clear plastic tubes. To my surprise there was no airtight barrier protecting them from the outer world's germs. Mole-rats are so hardy, she explained, that there’s no need for that. Underscoring the point, she suddenly picked one up and handed it to me. It was “the old man of the colony,” she said—her most senior mole-rat.
Up close he turned out to be oddly endearing, possessed of the bald, wrinkled, buck-toothed, querulous, squinty-eyed look of a slightly demented codger born well before the age of orthodontia. His exact age wasn't known—he’d been caught in the wild—but Buffenstein estimated he was pushing 29. It suddenly dawned on me that he might be the oldest rodent on the planet. I gingerly handed him back, feeling as if I’d been momentarily entrusted with a 2,000-year-old Han Dynasty vase.
The life style of the naked mole-rat Natives of East Africa, mole-rats were introduced to science in 1842 by Eduard Rüppell, a German naturalist known for heroically traipsing the biosphere and bringing pieces of it home. Despite their curious appearance, the rodents, officially named Heterocephalus glaber (meaning, roughly, weird-headed baldy), didn’t get much attention until Jennifer Jarvis, a Kenya-reared daughter of English missionaries, discovered in 1981 that they’re an extremely rare, mammalian version of social insects like termites. Each mole-rat colony is dominated by a large-bodied queen that mates with one to three consorts and produces hundreds of babies during her life. Intriguingly, the queens appear to keep workers in line by literally pushing them around, and when a royal mole-rat encounters a groundling in a tunnel she shoves it backward or walks over it. Such aggression appears to help suppress the lower orders’ fertility, as well as cue their subservient behavior—rarely-shoved workers in tunnels remote from the queen's chamber reportedly tend to goof off.
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15 Comments
Add CommentIt sounds like the first step is to make people larger!
Reply | Report Abuse | Link to thisSeriously, before selfishly extending the life of individuals (who can afford the price demanded!), perhaps science should be required to control population levels so that longer living individuals won’t simply be diminishing the resources available and the quality of life for the larger majority of individuals!
I don't find the Malthusian view on this very convincing, and not just because history showed that Malthus was wildly wrong. Rising economic prosperity (as well as more available resources and improving quality of life) has always gone hand-in-hand with healthier aging and greater longevity (which is the primary goal of most research on aging I'm aware of)--a correlation that makes sense, given that people who are healthier in old age tend to be healthier and more productive at younger ages too. I fail to see how neglecting the chance to give a major boost to healthy aging, and perhaps avert some of the heavy economic burdens of population aging, would help make the world a better place. And don't think it's selfish to seek to age as gracefully as possible, and thus, among other things, to impose fewer burdens on one's loved ones in old age.
Reply | Report Abuse | Link to thisBorn in 1950, in my life the population of the world has nearly tripled. Those born more recently have no qualitative basis for comparison. What you don't find or fail to see is that, while current forecasts indicate that the global population will increase to 'only' nine billion by 2050, those forecasts do not include any dramatic increase in the duration of those lives.
Reply | Report Abuse | Link to thisI'm not a mathematician, but if the human lifespan doubles, for example, the expected future population must significantly be increased, increasing demand for both housing and agricultural space requirements, already diminishing available potable water, and nutritional resources.
What you may find, the conditions you experience, as you become older remain to be determined, but I'm most concerned about the conditions my living grandchildren, and any progeny they may produce, must endure to survive.
U.S. life expectancy rose by about 64% in the 20th century (from about 47 to 77), thanks mainly to reductions in early-life mortality from better sanitation, diets, vaccines, etc.--not to decreasing late-life mortality. Now gains in life expectancy are flattening out. U.S. life expectancy rose by about 2% during each of the 1980s and 1990s, but over the past decade it has risen by only about 1.6%--not surprising, given how hard it is to increase life expectancy by trying to ameliorate diseases of old age one at a time, when much of their damage has already been done, which is how the longevity-increasing game is currently being played in much of the world. One doesn't have to be a mathematician to see that the idea that life expectancy will double this century--as you propose--is no more than wild speculation, contrary to current trends and, I might add, not based on anything I know of going on in the science of aging. (As I've written in a recent blog on Scientific American site's, I think it's possible that we might develop drugs in the not-distant future that can increase healthy life by 5-10 years.) So, as long as we're into wildly speculating, why not also speculate that during this century we see the advent of a clean, extremely cheap, carbon-free source of energy, of a second green revolution that doubles the amount of food-per-acre we can produce, of novel desalination technology that makes fresh water cheaply abundant worldwide, etc.? Still, if you prefer to stick only to gloomy speculations, why not consider a more likely one than doubled longevity: A future blighted by unhealthily aging populations across the world, thanks to our short-sighted refusal to pursue the development feasible anti-aging drugs that could greatly mitigate the fallout from population aging.
Reply | Report Abuse | Link to thisSo sorry - I didn't realize I was addressing a recent Scientific American bog writer, presumedly a recognized authority on the subject - thanks so much for pointing this out to me!
Reply | Report Abuse | Link to thisThe phrase "for example" used in my reference to doubling life expectancy was intended to indicate that I was not suggesting any such change, but using that change to illustrate the effects on net population growth and its demands for necessary resources. Sorry if that wasn't clear enough to you...
We've already experienced unprecedented growth of the human population - increasing from 2.5 billion in 1950 to an estimated 7 billion. The projected 2 billion increase by 2050 seems like a manageable increase over our current 'baseline', but in fact 2 billion people exceeds the largest total human population ever achieved until about 75 years ago. It was 200 years ago when the human population reached 1 billion people for the first time in the history of the Earth!
This means that a 1 billion plus human population has never experienced the climatic variation that normally occurs over any 500 year period! For example, the Chacoan culture is thought to have been decimated less than a thousand years ago when 500 year drought conditions persisted for 50 years. How prepared are our enormous desert cities and highly developed agricultural production for even normal climatic variation, much less any more devastating conditions produced by humanity's environmental impact over the past two hundred years? Do you presume that our populations are made immune from suffering brought on by catastrophic resource shortages by some amazing new seawater desalination technology? What are the long term repercussions of large scale implementations?
While development of life extending drugs or genetic treatments might seem to be magnanimous efforts to improve the quality of life for the masses, I suggest that these efforts are being pursued by commercial enterprises whose products will directed to select markets that can purchase costly health improvements and life extension technological advancements.
I suggest that billions of other humans now populating the planet must be left to continue to suffer the depletion of resources and accept increasing numbers of deaths. In the projected population of 9 billion, how many people would need to die daily to maintain zero population growth?
My views may be affected by my own health experiences over the past decade, but I think they are more realistic historical extrapolations than gloomy speculations.
I share your concern about current and future world populations exceeding the earth's carrying capacity, as biologists say. But I'm afraid I don't follow your logic, nor can I see a way to reconcile your assumptions with demographic facts.
Reply | Report Abuse | Link to thisYou assert, for example, that medical research to extend healthy life will benefit only a selected small subset of wealthy people. Yet at the time you argue that such an advance will somehow be applied worldwide to greatly increase surplus populations across the globe. These two assertions are at war with each other.
As a benefactor of medical advances made in the developed world, I would feel hypocritical about arguing that further such advances would be a bad thing because they might help future people live longer, healthier lives, increasing the world's future surplus population. Please note: The entire medical research enterprise is primarily aimed at increasing healthy life-years, and always has been--it's not just a matter of corporations lining their executives' pockets by keeping rich, old people alive longer, as you seem to think. Last I heard, longevity-enhancing medicines such as antibiotics aren't limited to helping people only in the developed world, so why would health-enhancing preventive medicines that modestly retard aging go only to "select markets that can purchase costly health improvements." Further, it seems to me that to be consistent, you must oppose all research aimed at improving human health/longevity -- and these two things necessarily go together, by the way -- in order to help limit the future surplus population on which you are fixated.
Lastly, you seem unaware of the fact that as longevity has increased around the world, birth rates have tended to fall, so that we're now facing a worldwide baby bust. The combined effect of these two huge demographic trends is accelerated population aging--a phenomenon that will have very large consequences this century, irrespective of what happens to population growth. Research on anti-aging drugs, which would abet healthy aging more cost-effectively than any other medical advance on the horizon, could greatly help mitigate the human suffering, as well as the potentially crushing economic burdens, of this global graying of populations. It's my firm belief that crushed economies don't make for sustainability.
Those who wish for an extended, healthy life would not admit that they wish it for themselves and their loved ones, but if extended life were made available to the entire population extended lifespans would produce enormous increases in expected population totals (unless there were a commensurate reduction in birth rates or increase in deaths from catastrophic events).
Reply | Report Abuse | Link to thisIn my experience, people who are near death would do anything, pay any price, to live a little longer. Are you sure that any commercial enterprise offering such a benefit would not maximize their profits from such strong and growing market demand for any successful product? After investing so heavily in R&D using capital raised based on glorious projections such as those being promoted by SA articles? In the final analysis, major programs to extend life are aimed at the growing financially vested, highly motivated customer base found in an increasingly aging population.
There is crucial biological purpose in death. New births are necessary to produce adaptations through natural selection, naturally producing a more healthy population.
Why not simply offer a program of pleasant, assisted euthanasia? This would benefit humanity and reduce personal suffering far more than any life extension compounding still increasing overpopulation issues? Personally, I have as strong a will to live as anyone, but overpopulation will be the end of us!
Sorry, meant to write beneficiary, not benefactor, in the prior post.
Reply | Report Abuse | Link to thisYour advocacy of a program of "pleasant, assisted euthanasia" to benefit humanity seems a little extreme to me, but I have to concede that it's in keeping with your arguments.
Reply | Report Abuse | Link to thisAs to whether there is a "crucial biological purpose in death"--the idea of an evolved death program, which you are voicing, was exploded by Peter Medawar and George Williams in the 1950s. More on this can be found in the first chapter of my book, in case you are interested in the evolutionary theory of aging.
The biology of death in mammals seems clearly intended to enable and support the renewal and replacement of the population base. Without population replacement there can be no natural selection of special characteristics to adapt to changing environmental conditions.
Reply | Report Abuse | Link to thisClearly it is the unprecedented size of the human population that is now controlling the global environment not just for humanity but the rest of Earth's flora and fauna. Our species' success in reproduction and longevity since our development of breakthrough technology 200 years ago is now the determinant factor in the survival of humanity and the planet we have engineered.
Continuing to focus our technological development on providing human comforts for individuals when it is actually the entire planet we are shaping is an irresponsible, degenerative and destructive policy.
JT, think of natural death as an Air Freshener. Making room for the next.
Reply | Report Abuse | Link to thisBut, I do wish I could show my dad the outcome of the computer revolution and digital photography. He'd have loved all this stuff.
It's all temporary... I hope we never see the final outcome, but I'm afraid...
Reply | Report Abuse | Link to thisJust curious if the author is familiar with the drug Selegiline HCL or its trade name of Deprenyl.
Reply | Report Abuse | Link to thishttp://www.ncbi.nlm.nih.gov/pubmed/9258898
http://www.ceri.com/deprenyl.htm
http://www.petplace.com/dogs/cognitive-dysfunction-in-elderly-dogs/page1.aspx
When working on the formulation in the 1990's for Parkison's drug some amazing studies were released for lifetime increase for the mice that were tested.
I'm sure Somerset Pharmaceuticals would be happy to provide the study information used in the original marketing. Teva now manufactures a generic version of this drug.
I'm somewhat familiar with the data on deprenyl, which I find interesting but pretty inconclusive as evidence that it can retard mammalian aging. The three promising early rat studies on its lifespan effects (by Knoll, et al.) were followed by others that found either no, or even adverse effects, and the data on its increasing maximum lifespan are decidedly mixed, though mean lifespan data are arguably less so. I'm mystified by its possible mode of action -- the best guess seems to be that it blocks oxidative damage in the brain, but if so, why haven't other antioxidants slowed aging? (And a lot of them have been tried over the years.) To me it seems that at this point there are more promising directions, such as TOR inhibition, to go in the effort to slow aging.
Reply | Report Abuse | Link to thisI'm not familiar with deprenyl, but according to your NIH reference's abstract, longevity has only shown to be increased for male mice and rats and, in the referenced study, female Syrian hamsters. In all those cases enhancement was shown in species with gender related differences in longevity, eliminating the normal gender distinctions. This led the researchers to speculate that deprenyl was interfering with the mechanism that produces gender longevity distinctions, stating:
Reply | Report Abuse | Link to this"These findings suggest that the increase of life span by selegiline might be independent of MAO-B inhibition, but is possibly related to mechanisms determining sex differences of life span."
It might be expected then that, in humans, deprenyl use might be able to extend men's lifespan to that of women, to the extent that the difference is produced by direct biological mechanisms and not due to increased risk of injury due to aggressive behavior, and other factors...