- Humans have weaker bones than hunter-gatherer counterparts, study shows
- Bone mass has dropped by 20% in all humans since 7,000 years ago
- Findings show that key to preventing bone weakness and osteoporosis is activity
- Analysis reveals the drop in strength was due to introduction to farming
Hunter-gatherers of 7,000 years ago had higher bone strength than modern man, a study at the University of Cambridge has found. By analysing prehistoric bones, the researchers found that modern human bone mass is up to 20% lower, making our bones lighter, weaker, and more susceptible to breaking than those of our cave-man cousins.
The drop in bone strength coincides with the introduction of farming and humans settling down for the first time in their history. Before this, humans lived highly active, nomadic lives – hunting animals and gathering food from local surroundings.
Researchers also found that there was no reason why modern humans couldn’t build their bone strength back to the levels found in prehistoric man and modern day orang-utans. However, even the most physically active people today are not experiencing enough frequent and intense stress on their bones to allow for strength to increase to its ‘peak point’ seen in hunter-gatherers.
The findings have implications for treating conditions such as osteoporosis, which sees a progressive weakening of bones in later life. Researchers believe that activity, rather than diet, is the overriding factor in slowing the loss of bone strength.
Dr Colin Shaw, from Cambridge’s Phenotypic Adaptability, Variation and Evolution (PAVE) Research Group, says “Hip fractures, for example, don’t have to happen simply because you get older if you build your bone strength up earlier in life, so that as you age it never drops below that level where fractures can easily occur.”
This research, showing activity as the key to regulating bone strength, also discounts previous ideas that evolution and changes in diet with the introduction of farming did not play a major role in the recent development of the human skeleton.
Shaw concludes “The fact is, we’re human, we can be as strong as an orangutan - we’re just not, because we are not challenging our bones with enough loading, predisposing us to have weaker bones so that, as we age, situations arise where bones are breaking when, previously, they would not have.”