Working at Night Damages the DNA, Results in Health Risks

Working at night shifts may cause damage to an individual's body and may result in long-term health problems, a recent study claims.

Sleep and system biology researchers from the University of Surrey found that jet lag or working at night could have a substantial impact on health. Researchers followed 22 participants on a 28-hour day schedule and delayed their sleep-wake cycle by four hours each day until they are able to sleep during the middle of the day. Derk Jan-Dijk and Simon Archer from the School of Biosciences and Medicine at said severe disrupting of a person's body clock provided surprising effects.

The researchers took blood samples of their participants and assessed the impact of working night shifts to their genes which are normally fine-tuned to a daily pattern. The results published in the Proceedings of the National Academy of Sciences showed that the change threw the subjects' DNA into "chaos". "Over 97% 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," said Archer. Dr. Djik said: "It's chrono-chaos. It's like living in a house. There's a clock in every room in the house and in all of those rooms those clocks are now disrupted, which of course leads to chaos."

"These rhythmic processes, together with posttranslational modification, constitute circadian oscillators in the brain and peripheral tissues, which drive rhythms in physiology and behavior, including the sleep-wake cycle. In humans, sleep is normally timed according to occur during the biological night, when body temperature is low and melatonin is synthesized. Desynchrony of sleep-wake timing and other circadian rhythms, such as occurs in shift work and jet lag, is associated with disruption of rhythmicity in physiology and endocrinology," the researchers said.