Chilean researchers set out to investigate whether humans could hibernate like bears, enabling us to snooze during trips through space that last longer than a lifetime, and say it’s unlikely to work because we wouldn’t save enough energy during hibernation. They looked at metabolism during hibernation in mammals ranging from bats to bears, and say a gram of tissue in a bat has a similar metabolism to a gram of tissue in a bear during hibernation, despite a bear being roughly 20,000 times larger. Working out the likely metabolism of a hibernating human based on our own mass, they found we save more energy by sleeping than we would if hibernating. The findings are bad news for sci-fi fans, suggesting humans will never be able to survive in suspended animation during long trips through space.
Journal/conference: Proceedings of the Royal Society B
Link to research (DOI): 10.1098/rspb.2022.0456
Organisation/s: Universidad Austral de Chile, Chile
Funder: This work was funded by ANID – Millennium Science Initiative
Program – Center Code NCN2021-050; ANID PIA/BASAL center
FB0002 and FONDECYT 1221073.
From: The Royal Society
Why bears hibernate? Redefining the scaling energetics of hibernation
In a hypothetical 120-year space voyage, a hibernating astronaut is mistakenly awakened and is unable to resume hibernation, after 30 years of travel. He is desperate, as it will die of old age before arriving to destiny. How realistic is human hibernation? Here, Roberto Nespolo and coauthors did a comparative analysis of hibernation metabolism in mammals, showing that a gram of hibernating bat has a similar metabolism to that of a gram of bear, 20,000 times larger (isometric scaling). Thus, for a mammal of the size of a human, the energy saved by hibernation is less than the energy saved when sleeping. It seems then, that human hibernation is constrained by metabolic scaling.
Sleep when you die – How realistic is human hibernation for a hypothetical future space voyage? Researchers compared the metabolism of hibernating mammals to estimate the daily energy expenditure of hibernation. The authors suggest that, for a mammal of the size of a human, the energy saved by hibernation is less than the energy saved when sleeping.