Bear study may lead to the prevention of osteoporosis

STATE COLLEGE, Pa. -- Understanding a bear's long winter nap might yield the key to fighting osteoporosis in humans.

Researchers analyzed blood samples from black bears hibernating in Virginia and found that the bruins did not experience profound bone loss while inactive.

In humans, bone regeneration slows or stops during prolonged periods of inactivity brought on by disease or injury.

The researchers now want to determine why bears continue to regenerate bone and look for ways to stimulate that process in humans.

The study appears in the March issue of the journal Clinical Orthopedics and Related Research and was done by Henry J. Donahue, a professor of orthopedics and rehabilitation at Penn State University College of Medicine in Hershey, and Seth Donahue, assistant professor of biomedical engineering at Michigan Technical University.

Seth Donahue said the study did not determine exactly why bears continue to regenerate bone. But he suspects a hormone or other chemical might be responsible, and the Donahues, who are not related, hope to do follow-up studies to test that hypothesis.

"If we can identify what that molecule is in bears that makes them resistant to osteoporosis, then perhaps that could somehow be used to prevent the onset of osteoporosis in humans," Seth Donahue said.

Osteoporosis affects around 10 million Americans, 80 percent of them women. Brittle bones can lead to fractures and hunched backs.

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On the Net

Penn State University College of Medicine: www.hmc.psu.edu/college

Michigan Technical University: www.mtu.edu/