Deep in the winter-dark woods, beneath the roots of a fallen tree, a mother black bear hibernates with her two yearling cubs. In the spring, they will wake up in a near starvation condition, their fat reserves depleted. The mother bear’s bones, however, will be as strong and as thick as the day she lay down, and her young may even have added bone mass over the winter.
Bears are the only animals known to maintain their bone mass during prolonged periods of inactivity. To consider what a feat this is, consider humans’ susceptibility to bone loss: astronauts who spend six months in the weightless environment of space can lose nearly ten percent of their bone mass, and people forced to spend several months in bed may experience similar declines.
So why are bears different? And what can we learn from their biochemical processes that may help us treat osteoporosis and other bone diseases? » Continue Reading.