Naked Mole Rats Offer Clues to Living Longer

These creatures live more than five times longer than would be expected for their size. Research into the biological mechanisms underlying their longevity could suggest ideas for slowing aging in people.














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At this point, the secret of their great durability is just beginning to come into focus. But research on the animals, and on other extraordinarily long-lived species such as bats, has already expanded gerontologists’ minds about aging in ways that studies on short-lived lab animals like mice couldn’t. Indeed, when it comes to aging, as with all else in the living world, evolution has generated "endless forms most beautiful and most wonderful," as Darwin so nicely put it. Not least among the strange beauties is a little buck-toothed burrower that ages like a demigod.

Adapted from The Youth Pill: Scientists at the Brink of an Anti-Aging Revolution, by David Stipp (www.davidstipp.com).


ABOUT THE AUTHOR(S)

David Stipp is a Boston science writer who has focused on gerontology since the late 1990s. His book on the subject, The Youth Pill: Scientists at the Brink of an Anti-Aging Revolution, was published in 2010, and his article, "A New Path to Longevity," appears in the January 2012 issue of Scientific American. Stipp blogs about aging science at www.davidstipp.com.


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  1. 1. jtdwyer 09:46 AM 12/21/11

    It sounds like the first step is to make people larger!

    Seriously, 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!

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  2. 2. dstipp 09:17 AM 12/23/11

    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.

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  3. 3. jtdwyer 09:41 AM 12/23/11

    Born 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.

    I'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.

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  4. 4. dstipp 04:52 PM 12/23/11

    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.

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  5. 5. jtdwyer in reply to dstipp 09:02 PM 12/23/11

    So 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!

    The 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.

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  6. 6. dstipp 09:45 AM 12/24/11

    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.
    You 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.

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  7. 7. jtdwyer 03:17 PM 12/24/11

    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).

    In 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!

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  8. 8. dstipp 03:28 PM 12/24/11

    Sorry, meant to write beneficiary, not benefactor, in the prior post.

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  9. 9. dstipp 03:57 PM 12/24/11

    Your 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.
    As 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.

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  10. 10. jtdwyer in reply to dstipp 10:03 PM 12/24/11

    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.

    Clearly 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.

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  11. 11. Quinn the Eskimo 11:17 PM 12/26/11

    JT, think of natural death as an Air Freshener. Making room for the next.

    But, I do wish I could show my dad the outcome of the computer revolution and digital photography. He'd have loved all this stuff.

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  12. 12. jtdwyer in reply to Quinn the Eskimo 07:39 AM 12/27/11

    It's all temporary... I hope we never see the final outcome, but I'm afraid...

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  13. 13. buckaroo_bonsai 11:27 PM 1/1/12

    Just curious if the author is familiar with the drug Selegiline HCL or its trade name of Deprenyl.

    http://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.

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  14. 14. dstipp in reply to buckaroo_bonsai 12:57 PM 1/3/12

    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.

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  15. 15. jtdwyer in reply to buckaroo_bonsai 01:23 PM 1/3/12

    I'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:

    "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...

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