Scientists Say the Future Looks Bleak For Our Bones 115
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."
Lazy farmer (Score:3, Insightful)
Yeah, because being a farmer is such a cushy gig.
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Yeah, because being a farmer is such a cushy gig.
Modern farm tractors are equipped with air-conditioned cabs and stereo systems -- Farming (in the first world) is a lot cushier than it used to be!
Re: Lazy farmer (Score:5, Interesting)
"pinpoints the origin of weaker bones at the beginning of the Holocene epoch roughly 12,000 years ago, when humans began adopting agriculture". This doesn't have anything to do with tractor farming.
Re: Lazy farmer (Score:5, Interesting)
But it does raise a serious issue - they're studying changes that don't necessarily reflect the selective pressures of present-day life.
Think about it: what are the leading causes of death for people in the prime breeding age (15-34)? Car accidents - by a good margin. So isn't this significant selective pressure to beef up the neck against whiplash, the skull against forehead impact, survival during significant blood loss, etc?
#2 is suicide. I don't know how this rate has changed over time or whether the methods modern humans choose for attempts are more effective than would have been chosen in the past. For example, while men commonly turn to firearms, which are a very effective way to commit suicide, women more often turn to prescription medication overdoses as a method, which overwhelmingly fails.
#3 is poisoning. While humans have always been around poisons, the sheer number that we keep in our houses, most of types that we didn't evolve to, suggests that this may be a stronger selective factor now than it was during our agrarian days, perhaps comparable to that when we were hunter-gatherers or worse.
#4 is homicide. We've definitely gotten a lot better at that, a person is far more likely to die from an intentional gunshot wound than a beating or stabbing. Selective pressures: surviving blood loss, mainly. Stronger, thicker bones may help in against low velocity penetrations.
#5 is other injuries. Again, we're not as likely to suffer from, say "crushed by a mastodon" as an injury, but we've developed plenty of new ways to get killed or maimed in our modern lives.
Then it gets more complicated on the basis that the issue isn't just about survival of the individual, but their social group as a whole, so even nonbreeding members can have a major impact...
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This would only work if everyone was constantly subjected to whiplash. The vast majority of people will never experience head trauma. And in increasingly lower numbers as cars get safer. In the 10,000 or so years for natural selection to show up, it will make no difference.
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Actually here [cdc.gov] are the real numbers. GP is pretty close, though.
It lumps all accidents together, I couldn't find a breakdown of them. But I am willing to be that car accidents are the vast majority of them.
1. Accidents (over 37% of all deaths in this range)
2. Suicide
3. Homicide
4. Cancer
5. Heart Disease
(HIV is #6 for the 25-34 group)
Cancer and Heart Disease are #1 and #2 overall. Those will tend to get almost everyone in the end. If you manage not to die young.
Now, comparing with the 2002 [cdc.gov] data, a large drop i
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Not every hunter-gatherer got crushed by a mastodon either - that doesn't mean it wasn't a selective factor in tribes that hunted them.
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Presumably, it was enough of a selective factor among mastodon hunters that they tended to breed people tough enough to be stepped on by a mastodon and live to tell the tale?
Thought not.
Not enough people get into auto accidents, much less die of them, to have much impact on whatever traits are being selected for via natural selection.
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Selective pressure is pressure if someone fails to breed as a result of the selective pressure.
For example, in the bacteria experiment it took them 3 different mutations in combination and tens of thousands of generations but they still eventually developed new beneficial abilities.
Bottom line, Everyone doesn't have to be constantly subjected to whiplash.
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Yes, farmers today spend some time in modern farm equipment. But most of that is only during the few weeks of planting in the spring and harvesting in the fall. The rest of the time it's still a very physical, demanding job. Try doing a major overhaul on a tractor or rounding up cattle for branding and vaccination if you think modern technology makes farming life easy.
But all the changes of modern agriculture happened too recently to have any evolutionary effect. Even with an ox or horse pulled plow, it sti
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And, the "farmer" no longer sits on the tractor, it is an immigrant laborer. The farmer sits in his office and deals with numbers while, according to this, his bones weaken. THe immigrant workers are on their feet all day, in and out of the tractor etc, etc.
Not at all like the old days. I remember (excuse the ramblings of an old man) working on a woman's house when one of my men stopped us and said he could hear someone calling for help. We honed in on the call and saw a tractor that looked parked in a fiel
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The article does not say that the farmer or farming itself causes weaker bones. The article implicates the societal impact of farming, i.e. food being more available and thus no need for the vigorous activity associated with hunting and capturing food, led to more people being more sedentary than before and thus loosing bone density in subsequent generations.
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The abstract says "Thus, the low trabecular density of the recent modern human skeleton evolved late in our evolutionary history, potentially resulting from increased sedentism and reliance on technological and cultural innovations."
The authors obviously know nothing about the history of agriculture. It wasn't until about 150 years ago that technology finally improved farming to the point where the dawn to dusk drudgery was reduced. Until then farmers easily walked as far as hunter-gatherers everyday, and p
Evolutionary tradeoffs... (Score:4, Interesting)
... 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.
Weaker bones and refined minds are not related (Score:1)
There are a lot of evolutionary trade offs, but weaker bones and refined minds are the two things that do not trade off against each others
A refined mind (for example, such as the one in Homo Sapiens Sapiens) consumes 20% - 25% of the total energy intake of the individual
To obtain a more refined mind one does not need to make one's bone "weaker" --- on the other hand, supercharging the intake process, for example, eating meat instead of digesting straws --- can supply the additional "energy consumption" th
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Thinner skull bones only mean one thing - earlier death !
Everything is a matter of balance. You can die from blows to the head, or you can die from being too slow to outrun an enemy/predator because your head is overly heavy. Depending on the lifestyle, you get a different optimum skull size. Also, the invention of helmets and other protective gear has allowed humans to survive better with thinner skulls.
The skull can expand outward, and has already expanded through the evolutionary process
Exactly, and for that reason, human childbirth is a slow and painful process with a high death rate. It also required human babies to be born earlier in the ges
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There's no real correlation between skull thickness and gestation. Infants have soft spots (fontanelles) between the bones of the skull that allow the brain to grow faster than bone after birth, precisely because humans need a relatively thick skull protecting a large brain. Child birth would be impossible otherwise.
A "soft spot" increases risk of head injuries. If there's no "real" correlation, then why did you observe that child birth would be impossible without this risky adaptation?
There would be no advantage in a thinner skull.
Except making child birth even more possible and less dangerous.
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Well, enjoy having the intellect of a dog or cat I guess.
My point was the obvious. The previous poster had ignored that there were tradeoffs to greater intelligence. Just because humanity has evolved a means for reducing the harm from a particular problem of the human body, doesn't mean the problem never existed. Instead, it indicates the opposite, that the problem was significant enough to create selection pressure for the means to evolve.
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Use multi-joint barbell exercises like squats and deadlifts. They build bone density and stave off the effects of osteoporosis.
Seriously? You are suggesting weight training to Slashdotters? Well, I suppose they could order the weights on-line and have them delivered to the basement, but could mom carry them down the stairs?
Re:just do strength training (Score:4, Insightful)
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.
Re: just do strength training (Score:1)
Right! Half the people in my club are somewhat geeks, bodybuilding is as important to me as coding and electronics. ;-)
Re: just do strength training (Score:5, Interesting)
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.
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Whooooooooosh!
Or perhaps the stereotype hit too close to home?
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hits close to home is that my IT coworkers and myself are middle aged and we HAVE to exercise to avoid problems. In other departments there are near-cripples our age that can hardly get up or move around and their life is one of misery and pain. screw that.
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The surfing, jiu-jitsu fighting, globetrotting etc. founder of my martial arts/crossfit club is a geek. The scoring system we use for competitions is something he cooked up in an afternoon. We also have an MMA fighter who's a banker and a surprisingly large amount of our members are university students. Psychology, medicine, and a couple of law students too.
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I'm mostly into kettlebells and olympic lifting myself, but I'll definitely second the statement that the first couple of months are absolutely amazing. Your endorphin levels will be through the roof, it feels so good.
I've been branching out into trying some yoga/mobility classes as well. That shit is tough.
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Use multi-joint barbell exercises like squats and deadlifts. They build bone density and stave off the effects of osteoporosis.
Or just drink some milk for the calcium and go for long walks when you're in your teenage years (especially for females), and of course later as well.
You could add some wrist and ankle weights to enhance the effect, oh, and get some sun for the vitamin D.
Our bones don't have to be as strong as our ancestors were, they just have to be strong enough to get us through our lifetimes without breaking down.
Somewhere, ... (Score:5, Funny)
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...those 16oz wrist curls and refrigerator door pulls (to get 1 nacho at a time) I've described before will soon take effect. It's all about intensity.
3D printers to the rescue (Score:3)
3D printed replacement skeletons to the rescue! Installation is a bitch, but you only have to do it once.
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Nanite deposited titanium weave?
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Exoskeleton, no need to install anything.
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Tell that to Miles Vorkosigan. [wikipedia.org] You can't replace a skeleton all at once; you have to do it piecemeal. They'll have to do it *lots* of times, a few bones at a time.
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Obesity (Score:4, Funny)
No, I refuse to believe this nonsense (Score:2)
I refuse to believe this nonsense. Since this type of doom and fear mongering has been going on now for many years now. It never comes true and it never is going to come true. If doom is going to happen, it is going to happen and nothing can be done about it and I am not sure if scientist are going to be the first one to know about or figure out what to do about it once the time comes, if it ever comes to start with. Since the human race has the chance of surviving as a species for the next 500 million year
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You are completely right. It is complete nonsense. I doubt a 'scientist' is behind it, more likely an idiotic reporter. Like the idiots who proclaim every few decades that red heads will die out because the gene is recessive. ... poor beasts no longer hunted by predators, no longer towing wagons ... their bones must be in an utter mess!
The same logic could be applied to cows or any cattle
Re: No, I refuse to believe this nonsense (Score:2)
"It never comes true and it never is going to come true.". It apparently happened 12,000 years ago
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the article claims the bones becoming weaker and weaker into the future to the point where you'll break your bones when you try to play golf for the first time. about.
Age prior to dyine (Score:3, Insightful)
Re:Age prior to dyine (Score:5, Informative)
Humans regularly lived to their 50s and 60s as far back as the paleolithic. Average life expectancy numbers are misleading because the high rate of infant mortality and death during childhood. A hunter-gatherer who can survive long enough to be a teenager is quite likely to live to old age, but it's getting that far that's the tricky part.
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Do you have any statistics on this?; like life expectancy at puberty through history?
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Re:Age prior to dyine (Score:5, Informative)
That is not how averages work. Yes, the average age was 20-30 years but that includes lots of children, newborns, and possibly war deaths (depending on which statistics you are looking at). Generally speaking if you lived to puberty then you had a reasonable chance to hit 60+ just like modern humans.
Also consider the introduction and increasing consumption of alcohol. It has significant calcium reducing properties.
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That is nonsense. The upper edge of mankinds life span did not change at all the last 40,000 years.
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Bull. The Bible itself tells us the full span of a man's years is "threescore and ten". That's from the Book of Psalms, and was probably written around 700 BC.
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Bull. The Bible itself tells us the full span of a man's years is "threescore and ten". That's from the Book of Psalms, and was probably written around 700 BC.
Not that I agree with the GP's 20-30 numbers, but I think he refers to humans who lived tens of thousands of years ago, not in relatively recent biblical times. You deleted his point that humans who lived more recently (which I parse to mean starting around biblical times) lived up to 70-100 years. I think those larger numbers are likely true of earlier humans too, but the premature mortality of those times cuts the average down.
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source: http://www.ancient-origins.net... [ancient-origins.net]
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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.
That is incorrect. Older Humans tended to die young due to disease, miscarriage, war, etc. Typically if they lived passed 20 they lived to 70-100 too.
Solution: adamantium (Score:2, Funny)
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Wolverine had the bony claws and regeneration first (even as a child). They were covered with adamantium much later.
Re:Flight (Score:5, Informative)
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.
-- origin unknown
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If humans could fly, we'd consider it exercise and never do it.
-- origin unknown
Fuck that! If I could fly, I would be everywhere. Hercules would look like flabby sack of flesh compared to me. I would be doing loops, speed diving, flying to the tops of mountains, over volcanoes. I would have circled the planet itself a dozen times by now.
Flying would be AWESOME. Who cares if it is exercise?
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Wow it seems like you have given this a lot of thought. You are not a bird, grow up.
Is there some aspect of my life that might be improved if I forgot my childhood dreams and flights of fancy? If so, I can not think of what might be improved. By all measures, I am quite successful at living life.
On the other hand, one has to wonder what motivated you to try and be critical... perhaps you are jealous of my freedom?
NOT a problem with VIAGRA (Score:4, Funny)
....Oh, oops, I thought it said BONERS.
Our Forefathers were Idiots (Score:2)
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What were they thinking, trading slightly more fragile bones for longer life spans, less dangerous lifestyles, philosophy, sanitation, modern medicine, equal rights, going to the moon, labor saving devices, the internet, quantum physics, cell phones, the internal combustion engine, and digital watches?
You forgot to mention laying the groundwork which would enable facebook. What were they thinking, indeed...
Challenging my bones (Score:2)
We are not challenging our bones with enough loading,
I do. That's why I still use a Compaq Portable [wikipedia.org] for my "laptop". It weighs about 28 lbs. (Joking aside, I actually had one of these - or something really, really similar - at the first company I worked for in the late 1980s.)
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Density vs fractures (Score:4, Interesting)
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).
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Squishy things flex, stiff things crack. It's not rocket science how bone density and fractures correlate.
Re:Density vs fractures (Score:4)
we know that dairy product consumption is correlated with higher density and fractures. There is no consensus on how to explain that,
If you're talking about this study, [bmj.com] there is no consensus that milk causes fractures other than "looks interesting, more study needed." Even the authors say that.
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What fields claim that bone density doesn't predict risk of fractures? There's a reason we do bone densitometry studies for people at risk of osteoporosis. Obviously they won't tell an individual whether or not they're going to have a bone break in the next 6 months, but for a population they're great for picking out who needs to pay more attention to their step and gait, and who could benefit from a bit of a bisphosphonate to sturdy up dem bones.
Read any reputable meta-analysis since the 80's and you'll fi
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So it really doe
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"The strongest body-builder is not close to our ancestors, or to chimps, in strength."
While you have some good points the above is false. The strongest humans are stronger than the strongest chimps and stronger than our strongest ancestors on record. With a population of over 7 billion individuals to pick from and extreme training we have now produced some extraordinary physical specimens.
What chimps have is greater muscle density. If they were as large as our largest lifters and got the same training then
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That was my thought too. I have trouble imagining that ancestral farming methods were any less strenuous and "bone-buliding" than even persistence hunting.
I've been reading a lot these days about correlations between the rise of agriculture (and the resulting high consumption of grains and carbohydrates) and worsened dental and overall health as well as shorter stature in humans.
I know that even with my own n=1 change in diet (from a "standard western diet" to a low-carb/high-fat) over the last year, my he
Study Written by a non-farmer (Score:3)
Clearly this study was written by someone who doesn't actually do agriculture in traditional ways as it has been done for the past tens of thousands of years. Farming, be it planting or herding, is not a cushy job. It's hard, vigorous work. I farm. I have dense bones as shown by X-rays I've had. I've also broken a lot of bones. Farming is hard, vigorous work and sometimes we break bones, just like we did doing hunting and gathering too. And what may be really surprising to those sitting in the ivory towers is we don't need to go see a doctor for a mere broken bone. It heals. Old skeletons show this, not just human or even primate but even T-Rex.
Re: Study Written by a non-farmer (Score:2)
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Oh, I understand but I disagree having experience with both.
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Unless you've lived as a hunter-gatherer I'm not sure why you're saying you've lived as both. Working in Ag is about the hardest job we still have as a human being but it's still an awful lot easier on the body than being a hunter-gatherer.
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You still don't get it. Nobody is saying that farming is not hard work or that it's even less hard work than the hunter/gatherer. Bone gets more dense from specific physical activity and not from all, for example running (which hunters do more than farmers) gives denser bone than walking (which farmers do more) and that is even if you walk for hours upon hours carrying heavy equipment vs running just a few hours.
What you also obviously miss completely is that it's a well established fact that the bones got
Wishful thinking (Score:1)
That's another one for the Luddites (Score:2)
Superbugs, environmental destruction, weakening skeletons, and other assorted genetic 'artificial selection' weakening agents.
For the sake of our short term comforts have we doomed the human species to a genetic inferiority and environmental destruction that could appear to conform to the idea that the candle which burns twice as bright only burns half as long?
In the long term perspective, will the trades have been worth it?
Or it doesn't matter because the universe is far too large to make finding another h