While Average Lifespans Increase, 114 Remains A Stubborn And Mysterious Upper Bound. Why?

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Ray Kurzweil predicts that in the coming decades the term “life expectancy” will become irrelevant. By then medical advances and nanotechnology will be such effective tools with which to repair our bodies as they break down with age it will be as simple as car repair, changing out old parts for new and getting us back on the road again. Indefinitely. Even without the breakthrough technologies that allow us to regrow organs or reprogram faulty genes technological advances are making their imprint on our longevity. But a puzzling part to the equation has emerged. While humans are in fact living longer lives on average, the oldest age that the oldest people reach seems to be stubbornly and oddly precisely cemented right at 114.

Life expectancy nearly doubled in developed countries over the 20th century. Prior to 1950 the increase was due mostly to a decrease in infant mortality. After the 1950s it was a decline in old age mortality that provided the main life-prolonging force. Improvements to the social and physical environments and breakthroughs in healthcare underlie both phases of mortality decrease. A person born in the US at the turn of the 20th century could expect to live 49.2 years. Their ancestor born in 2003 could reasonably expect to see their 77th birthday. But while average lifespans continue to lengthen, the oldest of the old appear to be encountering a rather powerful limiting factor. As reported recently in Slate, the number of oldest supercentenarians – people 110 and older – has stayed at around 80 over the past few years. And the age at which they die hasn’t changed over the past few decades. Data from japan is used to illustrate this. In 1990 there were 3,000 people 100 or older, the oldest of them being 114. Twenty years later the number of people aged 100 and over had grown to around 44,000, but the oldest was still 114. Robert Young, a gerontologist working for the Guinness Book of World Records, estimates that “the odds of a person dying in any given year between the ages of 110 and 113 appear to be about one in two. But by age 114, the chances jump to more like two in three.”

Number of people living to 110 years or older in Switzerland.

This phenomenon of everyone getting older but the oldest dying at the about the same age is called “rectangularization of the mortality curve.” A mortality curve tracks the probability that a person will be alive at a certain age. At birth the value is 100%. By year one it begins to slope downward, and around 70s, 80s, 90s it drops at a faster rate. In decades past the curve looked like a ski slope, hitting zero around 114. But the fact that more people are living longer lifts the curve and pushes it to the right so it looks more like a cliff than a ski slope – and more like a rectangle.

During our last Google+ Hangout we got a chance to hang with longevity researcher Aubrey de Grey, author of “Ending Aging” who once proclaimed “the first person to live to 1,000 was probably born by 1945.” We asked him about rectangularization, why it was that the whole ski slope doesn’t just move to the right but instead comes crashing down at around age 114. “This is a fascinating phenomenon and nobody has really much idea of what’s going on. What we do know is that it’s absolutely essential to not jump to conclusions about what’s going on. Time and time again over the decades past demographers have been brutally misled by short-term phenomena, by statistics gathered only over a few years. Blips happen for all manner of impenetrable reasons. In this case we’re talking about people born in a small segment of time, around 1900, and most of them born in particular countries and going through certain types of life they might not have gone through had they been born 20 years previously or 20 years later. There are many factors called ‘cohort effects’ that can cause early life phenomena to have an influence on longevity.”

Bottom line: don’t believe the hype.

“At this point I’m not exactly losing sleep over the phenomenon you’re talking about. I think that we’re probably going to see a resumption of the trend of everything just moving to the right eventually.”

Rectangularization of mortality.

De Grey also adds that medical developments could make rectangularization, much speculated upon in the study of aging, a moot discussion. “I don’t really care about whether I’m right or not about what I just said because it’s all going to become completely irrelevant when we have therapies that repair the damage of aging. Those therapies are going to make the whole concept of life expectancy…the way it’s calculated today will no longer exist.”

Because therapies will make life expectancies of the future, de Grey argues, so much longer than they are today, today’s estimates will become irrelevant. Like trying to compare Mark McGuire, Sammy Sosa and Barry Bonds to Babe Ruth. After steroids, all bets are off.

But that’s not stopping researchers from looking for the “longevity gene.” Sampling the genetic material of centenarians, researchers have seen strong correlations with several genes and the likelihood of living to 100. Two of them are involved in fat metabolism, a third in calcium metabolism.

Despite de Grey’s skepticism, if there really is a genetically-programmed limit around 114, seems to me that would make it all the more imperative to make good on the Longevity Dividend, the range of benefits to both individuals and society were we to stay healthier longer. Some argue that extending life will only postpone the inevitable disease and frailty that comes with old age. But if there were an upper bound that is not affected by current longevity trends, then the longest lifespans will not get longer but the period of age-related disease and frailty would be shortened.

Just my two cents for what they’re worth. Regardless of whether or not the upper bound is real, I agree with de Grey. Biologically, it is a fascinating phenomenon.

[image credits: dailygalaxy.com via Urban Times, Journal of Epidemiology & Community Health, and Archives of Gerentology & Geriatrics]
image 1: old age
image 2: longevity
image 3: rectangularization

Discussion — 17 Responses

  • VisIxR February 14, 2012 on 9:46 am

    life expectancy statistics are driven by infant mortality. On average, our babies are dying less, we aren’t necessarily living longer.

    • Alex VisIxR February 17, 2012 on 2:09 am

      I remember reading recently that the Japanese don’t count babies who die within the first two weeks as having ever lived; they’re listed as stillborn when it comes to official statistics.

    • turtles_allthewaydown VisIxR February 19, 2012 on 8:05 pm

      If you read the article, that led to most of the improvements up to about 1950. After that time, it’s been improvements in older age. Heart bypasses, diabetes care, rehabilitation after a stroke, artificial knees to keep people active longer, that sort of thing. And better treatment of severe injuries so that fewer die from accidents. Now most everybody dies from old age. We just call it different things.

      It’s going to take some kind of breakthrough to change that. We’re still waiting on that appetite suppressant breakthrough, and the anti-smoking pill. Health care has got some work to do to catch up to the singularity.

  • nabra February 14, 2012 on 10:13 am

    What about the improvement in data? Why should we believe that the error bar for age from 100 years ago is 0?

    This question occurs to me both from this writeup, as well as the original Slate article. Error bars and coincidence and confirmation bias (everyone asked their age would be encouraged to report a conforming age) could easily explain the clustering of ages to 114. What would be interesting is when people start hitting 114 after the creation of extremely low error bar birth certificate data.

    • turtles_allthewaydown nabra February 19, 2012 on 8:01 pm

      Confirmation bias actually led to greatly inflated ages. People lied about their ages, sometimes assuming identities of older people to avoid the draft or to improve their stature, such as the search during Stalin’s time to find centenarians from his home state of Georgia. They thought there was a hot-spot of people living well past 100, and they found what they were looking for – many living past 114. Of course, it was all a lie to please Stalin. Therefore, there have been strict requirements on documentation for those who are accepted into the super-old hall of fame.

  • visualign February 14, 2012 on 2:51 pm

    Death is part of evolution. Our bodies not only can’t live forever; they have evolved to die. Human mortality rates approximately double every 8 years. This is known as the Gompertz Law of Mortality. When you draw mathematical curves their shape looks very similar to that of real measured populations.

    As a result of the mortality rate growing exponentially, survival probability decays super-exponentially with the big steep slope around 80 years old. Beyond 110 or so the survival likelihood is just getting vanishingly small. I did a recent write-up on my Data Visualization Blog here:

    http://visualign.wordpress.com/2012/01/12/nonlinearity-in-growth-decay-and-human-mortality/

    There is also a so called “cops-and-criminals” metaphor of our immune system which attempts to explain the underlying mechanism responsible for this dynamic. Interesting comparison of abstract model and real human nature…

  • dobermanmacleod February 14, 2012 on 3:03 pm

    Immortality will come to such as are fit for it.

    The only proven way to extend life is to go on the CRdiet. Most people simply don\’t have the disipline, and such (in my opinion) are not fit for immortality.

    • Gilbert Midonnet dobermanmacleod February 16, 2012 on 5:20 pm

      So, only ascetics ought to live longer? I have to disagree with you there. There is a balance, a golden mean, between asceticism and gluttony.

      • dobermanmacleod Gilbert Midonnet February 16, 2012 on 9:40 pm

        I believe I said “immortality,” not “live longer.” In my opinion, disipline is a necessary charactor trait for immortality (although, necessary in terms of functionality, not taste). Balance may be a “golden mean” in terms of beauty, but in terms of necessity I believe immortality would requiore a more rigid set of standards.

        • Gilbert Midonnet dobermanmacleod February 18, 2012 on 9:34 am

          Fair enough. I agree tha discipline is a necessary character trait – but I was commenting more on the necessity of the CR diet than anything else. How are we defining the CR diet? Are we trying to restrict calorie intake or keep body fat to a minimum?

          Both require discipline. Semi-starvation appeals to the ascetic; the other focuses on optimal health. Maybe I’m splitting hairs here – but most CR people I’ve come across glorified their self-sacrifice. That is not something I consider to be mentally healthy.

          • dobermanmacleod Gilbert Midonnet February 18, 2012 on 12:38 pm

            Given my extensive survey of people I meet, most people don’t consider immortality healthy (either physically or mentally) either. The CRdiet is a restrictive calorie diet, the goal being to delay senessence primarily. BTW, if you cut your calories by about half, you’d probably bragg about it too (it is an accomplishment). Also, I think that discipline is probably the most important charactor necessary to extend your life significantly.

  • ThomConspicuous February 16, 2012 on 6:12 am

    “Biologically, it is a fascinating phenomenon.”
    It could be possibly very fascinating…if anything in this article was factual.

    Ray Kurzwell should broaden his studies to include real data.
    http://en.wikipedia.org/wiki/Oldest_person
    “he longest unambiguously documented human lifespan is that of Jeanne Calment of France (1875–1997), who died at age 122 years, 164 days.”

    10 expired lives listed at older than 114 in that article I just linked. 4 more living people in this world that are older than 114.

    • turtles_allthewaydown ThomConspicuous February 19, 2012 on 7:53 pm

      Numerically speaking, 10 people out of 7+ billion is zero. (0.000000014%). Currently only one person is 115. When the odds are above 1%, then I’m interested.

      BTW, your quote is from the author, Peter Murray, not Ray Kurzweil.

  • Fabio February 16, 2012 on 5:57 pm

    There’s a related story showing up at the bottom of the article that is titled “World’s Oldest Person Gertrude Baines Dies at Age 115″.

    Says it all, I guess. :)

    Here’s the link: http://singularityhub.com/2009/09/15/gertrude-baines-dies-at-age-115/

  • Alex February 17, 2012 on 2:07 am

    When it comes to the ceiling on age at about 114, maybe there is an inverse Grandmother Hypothesis?

    When the children and grandchildren get to a certain age they can no longer look after their parents and grandparents and so they lose the support needed to go on living. Great-grand parents and great-grand children don’t have much in common so they spend minimal time with each other.

    There may also be a psychological ceiling too, many don’t want to live when they get to the 100 year mark so they lose the will to go on.

  • turtles_allthewaydown March 8, 2012 on 1:27 pm

    Interesting work on planarian worms (a type of flat worm), that are apparently resistant to aging. At least in the asexual type of the worm, it is related to telemeres as expected, but they don’t have the mechanism figured out yet in the sexual type of worm. Might yet be a breakthrough in this area.

    See:
    http://www.ibtimes.co.uk/articles/305644/20120228/asexual-worms-key-immortality.htm

  • Betsy Jacobson April 28, 2013 on 12:56 pm

    “Ancestor” is NOT interchangeable with “descendant,” people. Someone born in 2003 is in no way the ancestor of someone born at the turn of the 20th century.