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Scientists Say the Future Looks Bleak For Our Bones
HughPickens.com writes 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 deskbound 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."
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 deskbound 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."
Yeah, because being a farmer is such a cushy gig.
... what we get in weaker bones, we get in more refined minds (aka sitting and reading, researching, etc). Now some may laugh at this idea in the modern era, but you have to remember you only have so much time and energy as an organism. It'd be interesting to know whether bones needing lower maintenance/energy has some pro's instead of just cons.
Have gnu, will travel.
you have stereotypes that may not stand up to reality. Plenty of slashdotters and IT geeks exercise. Even more important than the weight training is cardiovascular health: power walk, jog, run, or swim, etc.
Maybe the added weigh of obesity, will cause more force on our bones and compensate for the lack of it by moving less.
The older humans lived 20 - 30 years MAX. The new humans live to 70 - 100 so there is pleanty of time for the new humans to break or splinter the old bones. The older humans didn't live long enough or stress the older bones nearly as much.
....Oh, oops, I thought it said BONERS.
It is amazing how researchers are able to ignore results from other fields. We know that bone density is not a good predictor for fractures. On the other hand, we know that dairy product consumption is correlated with higher density and fractures.
There is no consensus on how to explain that, but one interesting theory is that dairy products promote bone metabolism (hence the higher density) up to renewal exhaustion (hence the fractures).
Classic nerds vs. geeks. Nerds are happy to be sacks of goo because exercise is not interesting to them. For geeks, everything is an optimization problem - the meatsuit gets no pass.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
Modern human skeletons have shifted quite recently towards lighter—more fragile, if you like—bodies.
Sweet! Maybe we will also start evolving wings and finally be able to fly without manufactured air foils! I for one intend to sit on the couch more and make this happen faster!
If humans could fly, we'd consider it exercise and never do it.
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