Jet lag and shifting sleep schedules can take a toll on the human body. But scientists may have found a way to adjust the circadian rhythm, more commonly known as the biological clock, and “reset” it so that recovery goes faster – at least, in mice.
The solution appears to be thin air. Researchers led by Dr. Gad Asher, a clinician and assistant professor at the Weizmann Institute of Science in Rehovot, Israel, discovered that dips in oxygen levels for a brief period helped mice adjust more quickly than when they received steady levels of oxygen, Live Science reports.
The idea of fluctuating oxygen levels may sound dangerous, but the mice were only exposed to small changes that were not harmful. The researchers mimicked the amount of oxygen commonly present in airplanes.
The study aimed to take a closer look at the body’s circadian rhythm, which is found in the brains of almost all mammals. This biological clock somehow affects every cell in the body, but scientists have been puzzled as to how this communication happens.
The researchers observed that oxygen levels in mice appeared to change regularly, and deduced that this might be the missing factor.
Upon experimenting, they found that oxygen levels in mice cells rose at night when they were active, and dropped when they were at rest during the day.
In a lab where cells were cultivated in dishes, the team changed oxygen levels by 3% and found that they could “reset” the circadian clocks on the cells.
They then exposed the mice to two conditions: stable oxygen levels at 21%, which is the same volume humans breathe at sea level, and oxygen levels starting at 21% that decreased to 16% for 12 hours, then went back up to 21%.
The mice showed no initial response to the changing oxygen levels. But when the researchers tried giving them jet lag by exposing the mice to daylight six hours ahead, they saw the effects. Upon experiencing lower oxygen levels, the jet-lagged mice were able to adjust to new sleeping, eating and physical activity schedules, compared to the mice that breathed in steady oxygen levels.
It’s not clear if the results apply to humans, as well, but the study can help in aviation practices. The researchers hope to study if higher oxygen levels can also shift an animal’s biological clock.
The study was published in Cell Metabolism.