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posted by janrinok on Friday December 26 2014, @12:27PM   Printer-friendly
from the dem-bones-dem-bones-dem-dry-bones dept.

Nicholas St. Fluer reports at The Atlantic that according to researchers, our convenient, sedentary way of life is making our bones weak foretelling a future with increasing fractures, breaks, and osteoporosis. For thousands of years, hunter-gatherers trekked on strenuous ventures for food with dense skeletons supporting their movements and a new study pinpoints the origin of weaker bones at the beginning of the Holocene epoch roughly 12,000 years ago, when humans began adopting agriculture. “Modern human skeletons have shifted quite recently towards lighter—more fragile, if you like—bodies. It started when we adopted agriculture. Our diets changed. Our levels of activity changed,” says Habiba Chirchir, A second study attributes joint bone weakness to different levels of physical activity in ancient human societies, also related to hunting versus farming.

The team scanned circular cross-sections of seven bones in the upper and lower limb joints in chimpanzees, Bornean orangutans and baboons. They also scanned the same bones in modern and early modern humans as well as Neanderthals, Paranthropus robustus, Australopithecus africanus and other Australopithecines. They then measured the amount of white bone in the scans against the total area to find the trabecular bone density. Crunching the numbers confirmed their visual suspicions. Modern humans had 50 to 75 percent less dense trabecular bone than chimpanzees, and some hominins had bones that were twice as dense compared to those in modern humans. Both studies have implications for modern human health and the importance of physical activity to bone strength. “The lightly-built skeleton of modern humans has a direct and important impact on bone strength and stiffness,” says Tim Ryan. That's because lightness can translate to weakness—more broken bones and a higher incidence of osteoporosis and age-related bone loss. The researchers warn that with the desk-bound lives that many people lead today, our bones may have become even more brittle than ever before. “We are not challenging our bones with enough loading," says Colin Shaw, "predisposing us to have weaker bones so that, as we age, situations arise where bones are breaking when, previously, they would not have."

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  • (Score: 5, Interesting) by mtrycz on Friday December 26 2014, @12:45PM

    by mtrycz (60) on Friday December 26 2014, @12:45PM (#129268)

    1. If you're not doing sports, you're gonna live both shorter and less healthy. I prefer martial arts, but to each his own.
    2. It's gatherer-hunter, not hunter-gatherer.
    2a. Also, it's not "strenous ventures" as they foraged some 20 hours weekly, spending the rest of the time having fun.
    3. TFS doesn't even state the comparison of modern to prehistoric homo sapiens (skimed thorugh TFAs, but too many to pinpoint the %)

    Mr. Pickens, please stop spreading "common sense" disinformed bullshit.

    Bonus point: Drinking cowmilk in adulthood will hurt your bones more.

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    • (Score: 5, Interesting) by digitalaudiorock on Friday December 26 2014, @07:26PM

      by digitalaudiorock (688) on Friday December 26 2014, @07:26PM (#129328) Journal

      I'd say the most important form of exercise for skeletal strength is weight bearing exercise. As a matter of fact, I'd say it's importance is usually way understated in general.

      I keep hearing about people actively playing sports into old age (running, biking, tennis, whatever), and ending up needing knee and hip replacements. I'd argue that's because the single most important way to keep healthy joints is strong muscle mass around those joints, and as you get old you are going to loose muscle mass without very proactive weight bearing exercise. Without that, the activities you continue to do beat the crap out of your joints in ways they never did before. I'm sure some will disagree, but I really think there simply is no replacement. That's why all professional in every sport hit the weight room.

      I read once that the average man between the ages of 50 and 70 looses a full third of their muscle mass...that's scary stuff.

      • (Score: 1) by Nephandus on Saturday December 27 2014, @02:49AM

        by Nephandus (4656) on Saturday December 27 2014, @02:49AM (#129391)

        Do you even lift?

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        • (Score: 2) by digitalaudiorock on Saturday December 27 2014, @02:14PM

          by digitalaudiorock (688) on Saturday December 27 2014, @02:14PM (#129461) Journal

          Absolutely..you seem to ask as though you assume I don't(?)...two days a week almost without fail for over 22 years. I do one day of abs, legs, and lower body weight exercises and one day of all upper body weights...all at home, mostly with free weights. I tend to lift on the heavy side trying to push myself. I also do 20 minutes of very intense aerobics three times a week by the way.

          At 61 I can honestly say I feel better than I did in my 20s..all kidding aside. The most surprising thing is the fact that I've even gotten stronger over the last ten years...so yea...loosing muscle mass with age is very much preventable.

      • (Score: 0) by Anonymous Coward on Saturday December 27 2014, @05:35AM

        by Anonymous Coward on Saturday December 27 2014, @05:35AM (#129398)

        there are different muscles in our bodies for bearing weight

        the weight-bearing muscles are the ones that astronauts have to exercise when they spend long periods in space

        apparently walking on soft sand is a good way to exercise the 'anti-gravity' muscles

        • (Score: 2) by digitalaudiorock on Saturday December 27 2014, @02:32PM

          by digitalaudiorock (688) on Saturday December 27 2014, @02:32PM (#129464) Journal

          apparently walking on soft sand is a good way to exercise the 'anti-gravity' muscles

          Interesting! I have to think that squats are a great overall weight bearing exercise. Not long ago I added them back into my workout...had been doing other things in place of those...huge improvement. Those things work so many muscle groups...just a great exercise.

  • (Score: 4, Informative) by kaszz on Friday December 26 2014, @01:03PM

    by kaszz (4211) on Friday December 26 2014, @01:03PM (#129270) Journal

    "our convenient, sedentary way of life is making our bones weak"

    So get out and move your ass. It's that simple even if circumstances can be complicated. Neighborhoods with every spot built upon, blocking roads, crime ridden, or just too many tasks to deal with etc.

    • (Score: 5, Insightful) by art guerrilla on Friday December 26 2014, @03:01PM

      by art guerrilla (3082) on Friday December 26 2014, @03:01PM (#129280)

      i was going to moderate in this thread, but want to amplify what you are saying, and how it is undermined by a bizarro-world society...

      not sure your age, but when i was a yard ape, we were outside ALL the fucking time, roaming around (lots of times where we 'weren't supposed to'), almost (mostly) getting into/out of trouble (of a minor and inconsequential nature), playing kickball with rules made up as we went, climbing trees taller than our house, riding our bikes EVERYWHERE (WITHOUT helmets ! ! ! *gasp*), getting chased by dogs, shooting slingshots at things we probably shouldn't have, playing war with sticks, throwing water balloons at each other, making mudpies, throwing mud pies at each other, whacking hornet's nests (and it IS as stupid an idea as you would imagine, but it will spike your adrenalin!), making tree forts, making leaf forts, making cardboard box forts, making snow forts, having vicious snowball fights, sledding until you were encrusted in snow and your snot was frozen, conversely, running around summer days/nights until we had dirt in every crease of our skins, then running through the sprinklers...
      dog damn, those was some good times... probably the last time i was truly 'free', in many respects...
      now ? ? ?
      r u fuggin' kiddin' me ?
      99% of that shit is illegal or would land the parents in jail and the kids in 'protective kidnapping, er, services', and a lifetime of being in/out of various institutions and jails...
      LIFE has been criminalized, and it is only a matter of if/when sauron turns his all-seeing gaze in your direction and decides to jack you up...
      we are ALL vulnerable...

      Empire must fall.
      the sooner the fall,
      the gentler for all...

  • (Score: 5, Interesting) by Joe on Friday December 26 2014, @05:35PM

    by Joe (2583) on Friday December 26 2014, @05:35PM (#129300)

    Bone remodeling is done by two main cell types - osteoblasts that make bone and osteoclasts that break bone down. The balance of the numbers/activity of these cells determines bone density and are regulated by stress and calcium needs.

    Maybe we just have weaker bones do to less activity as the summary says.
    Or maybe:
    Bone remodeling is resource intensive process that happening constantly and those resources were better spent elsewhere with a change in lifestyle.
    Our immune system became a higher priority which resulted in more myeloid cells and, in turn, osteoclasts.
    We had a greater need for the immunomodulatory functions of mesenchymal stem cells (the progenitor of osteoblasts) or they differentiated into fat or cartilage cells instead - less osteoblasts

    I don't know what the reason is, but it would be interesting to know what process actually drove the change in bone density and if there were any physiological changes that resulted from it.

    - Joe

  • (Score: 5, Insightful) by frojack on Friday December 26 2014, @06:21PM

    by frojack (1554) on Friday December 26 2014, @06:21PM (#129311) Journal

    So, what the story is talking about is long term optimization of the body to its environment.

    The team scanned circular cross-sections of seven bones in the upper and lower limb joints in chimpanzees, Bornean orangutans and baboons. They also scanned the same bones in modern and early modern humans as well as Neanderthals, Paranthropus robustus, Australopithecus africanus and other Australopithecines.

    So what it is NOT ABOUT is sports vs sedentary. Nor about any temporary change in your bone mass that you can induce over your pathetically short lifetime.
    This is an evolutionary change, and at best you cat reshuffle the hand you were dealt and make small changes in your cards, but you are never clawing your way back to par with a chimpanzee.

    Some changes in bone density and size can occur. Baseball pitchers [sciencenews.org] have been studied and differences between their throwing arm and non-throwing arm can be marked, but for the rest of us you simply can not stress ALL OF your bones enough to make any lasting significant change.

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    • (Score: 3, Interesting) by darkfeline on Saturday December 27 2014, @12:00AM

      by darkfeline (1030) on Saturday December 27 2014, @12:00AM (#129374) Homepage

      Yes, this is what bugged me about the summary and all the early comments. Why would this change be associated with the switch to agriculture? Is agriculture really less physically demanding than foraging? Even if it was, if agriculture isn't physically demanding enough to promote our original bone health/integrity, what makes you all think that a few hours of sports every week is?

      Given that this is associated with the development of agriculture, I would guess that it is a result of the significant diet change (balance of nutrients plus the relatively more stable/guaranteed source of food).

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