Hibernating bears could help astronauts stay healthy

Alan Martin July 10, 2015

What do black bears and astronauts have in common? On the surface of it, pretty much nothing – but one key difference between bears and humans could offer a breakthrough for extended space missions.

Hibernating bears could help astronauts stay healthy

Let’s start with the astronauts. One of the big problems with extended low gravity is the effect is has on the bones. Weightlessness leads to spaceflight osteopenia, in which reduced impact leads to bone degradation. Astronauts can lose around 2% of their bone mass in a single month, so missions are typically cut short to ensure no lasting damage.

Astronauts exercise to try and limit the damage, but it hasn’t proved hugely effective. So what can be done?

Step forward the black bear. black_bear_smiling

No, we’re not going to put bears in space suits. Sorry.

“If humans could copy the bear’s trick, then both astronauts and sufferers of bone-related chronic illnesses could benefit.”

In a new study, black bears have been found to avoid bone degradation in hibernation by suppressing the release of calcium from bones into the bloodstream. This means that while the bears were in hibernation, they simply weren’t continually rebuilding bone tissue. Bone-regenerating cells – osteoblasts – dropped from 2% when active to just 0.15% when hibernating.

Humans don’t do this – a similar six months of zero movement would lead to severely weakened bone structure. However, if humans could copy the bear’s trick with therapy, then both astronauts and sufferers of bone-related chronic illnesses could benefit.

“We know that hibernation is controlled by the brain. Our next step is to understand how these proteins and enzymes get turned down by a bear’s brain to reduce bone loss,” Professor Meghan McGee-Lawrence, one of the study’s authors, told The Guardian.

If they can get a handle on this, and astronauts can take a leaf out of the black bear’s book to suppress their bone loss, then one of the many hurdles to putting humans on Mars would be cleared. Navigating the harsh conditions of Mars with weakened skeletons could lead to significant health issues manifesting themselves.

“Navigating the harsh conditions of Mars with weakened skeletons could lead to significant health issues manifesting themselves.”

It might not be the only thing the hibernating black bear can teach us. Describing hibernating bears as “metabolic marvels”, Dr Seth Donahue from Colorado State University reckons they could teach humans about dealing with obesity and inactivity too.

Helping astronauts and the obese. Who’d have thought we could learn so much from animals not moving?

Images: Neal Herbert and Sheila Sund used under Creative Commons