Researchers found changing sleep cycles can disrupt natural rhythms in the genes.
A research team placed 22 participants on a 28-hour day controlled sleep cycle that did not have a light-dark cycle. This caused their sleep-wake cycle to be delayed by four hours every day until they were running 12 hours out of synch with their "brain clock," a University of Surrey news release reported.
"This research may help us to understand the negative health outcomes associated with shift work, jet lag and other conditions in which the rhythms of our genes are disrupted," Senior author Professor Derk-Jan Dijk, from the Sleep Research Centre at the University of Surrey said in the news release.
"The results also imply that sleep-wake schedules can be used to influence rhythmicity in many biological processes, which may be very relevant for conditions in which our body clocks are altered, such as in [aging]," he said.
The participants experienced the beginning of their sleep cycle during what would have been the middle of their day.
The team collected blood samples from the study subjects to determine "the participants' rhythms of gene expression," the news release reported. The researchers observed a "six-fold" decrease in genes that displayed a natural circadian rhythm (the body's 24-hour "clock").
"This included many regulators associated with transcription and translation, indicating widespread disruption to many biological processes," the news release reported.
The research helped determine which genes are regulated by central body clocks and which linked to sleep cycles. It also showed how sleep cycles differ from natural circadian rhythms in affecting biological functions.
"Over 97 [percent] of rhythmic genes become out of sync with mistimed sleep and this really explains why we feel so bad during jet lag, or if we have to work irregular shifts," Co-author, Doctor Simon Archer, from the School of Biosciences and Medicine at the University of Surrey, said in the news release.
