As we age our bones become more brittle, osteoporosis sets in and our bodies become more susceptible to break under great stress. Milk and a good diet--we're told--is supposed to help enhance our bone strength and act as a preventative measure. But two groups of anthropologists claim our brittle bones have nothing to do with a lack of a proper diet. They believe our sedentary lifestyle is the cause of our degrading bone density.
Nicholas St. Fleur from The Atlantic writes on two recent studies that both come to the same conclusion: Our sedentary lifestyle is causing us to have brittle bones. Colin Shaw from the University of Cambridge in the U.K. compared the bone density in the hip joints of foragers 7,000 years ago to farmers of 700 years ago.
“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.”
In Shaw's study, he put the bones through a CT scanner and found the bones of the foragers had 20 percent more bone density than the farmers. The farmers lost as much as astronauts do today when they travel into outer space. Compared to our ancestors who had to hunt and forage for their meal, we have ours delivered to our doorsteps or we drive a car to the supermarket. The fact is humans aren't walking as much as we used to.
In a separate study, Brian Richmond, a Research Professor at George Washington University, looked at the density between the foot bones of chimpanzees and humans. His team of researchers expected to find the latter to have the higher density, since we're up on our feet more often, but not so. They then went on to find out why, comparing the densities between modern humans to those from the early farming era with chimpanzees and our ancestral hunter-gatherers. Modern humans only have three-fourths to one-third the bone density of ancient human foragers and chimpanzees.
“What our studies show is that modern people today have much less bone density than we should.”
The next step for these researchers will be to look at modern athletes that push their bodies further than the average joe. But for now, the results show that it's our sedentary lifestyles that are causing our bones to become more brittle and susceptible to osteoporosis.
Some of our ancestors settled, and began to practice farming. There began our bone loss. Researchers studied a variety of bones from the paleolithic time period onwards. The drop in bone density was steady in lower limbs, leading to where we are today.
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