by David Illig
Can Black Bears Provide a Cure for Osteoporosis?
Have you ever been bedridden, or forced to relinquish use of your muscles for a week or more? If so, you’ve no doubt felt weak and required a period of exercise to recover your strength. In humans, too little use of our musculoskeletal system, as well as increasing age, causes emigration of minerals from our bones and weakness of our muscles. Doctors recommend weight-bearing exercises to prevent this loss so that we’ll stay strong.
Black bears don’t suffer from this ailment, not even in their old age. Depending on where they live, black bears spend between 2 and 5 months curled up and fairly motionless in a den for the winter. This scenario would make a human downright decrepit. Yet when spring comes, a stretch and a yawn, and a bear is out and about, scrounging for food, none the worse for wear. Bones and muscles have not atrophied. This physiological marvel has given rise to hope that bear research will eventually help curb osteoporosis and other ailments in humans.
Although research has found that bears do experience bone loss during hibernation, bone regeneration counteracts it. During their winter sleep, black bears become a closed system. They don’t drink or eat, nor do they defecate or urinate. Stored fat is their only source of energy for metabolic processes. Heart rate and breathing rate slow, but a bear is able to respond fairly quickly to a disturbance, unlike a true hibernator like a ground squirrel, woodchuck or little brown bat. Most bone that is lost during inactivity re-circulates and is formed into new bone. When a bear begins activity once again, regeneration of any bone deficit is speedily accomplished. The solution may boil down to a hormone – the parathyroid hormone.
Researchers have also discovered that bear plasma contains some sort of substance that inhibits the deterioration of muscles during inactivity. In humans, and many other animals, both bone loss and muscle atrophy are dangers of the lack of mobility. Not so for black bears. Research is aimed at identifying this substance found in bear’s blood, with hopes it will alleviate muscle deterioration, caused by diseases like malnutrition, AIDS, and cancer.
So I say, “Yea” for Ursus americanus, the American Black Bear. I knew bears were very cool animals. They are such charismatic creatures, intriguing, and smart. Individuals have as distinct personalities as individual humans. Their cuddly, huggable look tends to draw us close, but their strength and formidable potential provokes us to keep a respectful distance.
The Cherokee have a legend telling of the origin of the black bear, which is sacred to them. Black bears were once a clan of Cherokee people who decided to turn to the forest and mountains for their sustenance, instead of farming. You can just see the human-like qualities of a bear as it ambles about, eating a wide variety of plants and animals, to appreciate the origin of this legend.
The value of a creature can be gauged in many different ways. Ecology-oriented individuals often recognize the value of a given creature in terms of its niche or role in the balance of nature. I know there are the hard-core or the uninitiated who see merit in a creature only in its possible benefit to the human population. Others, myself included, are firm advocates of the merit of a living creature simply because it exists. I have heard kids ask of bugs, “What good is it?” Yet I hope that through my facilitation of their discoveries, these kids come to realize it is not our place to ask such a question but to accept a creature’s very existence as its license to survive.
No matter where you sit along the spectrum of respect for wild things, the black bear is undeniably a fantastic, necessary and amazing creature, most assuredly so, whether it helps cure our ailments or not.