Working night shifts causes “chaos” for people’s bodies and may result in long-term health problems, scientists have warned.
Sleep researchers found that not only does irregular shift work have a similar effect to severe jet lag or repeatedly missing sleep, it has a damaging impact right down to the level of our DNA.
Professor Derk-Jan Dijk and Dr Simon Archer, from the School of Biosciences and Medicine at the University of Surrey, said the “severe” effects of disrupting a person’s natural body clock took hold “surprisingly quickly”.
Their study, conducted at the Sleep Research Centre in Surrey, set 22 volunteers onto “28-hour days”, meaning their sleep patterns were shifted by four hours each night.
Once the test subjects had fully moved over to the routine of a typical night shift worker, blood samples were taken to assess the impact on 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 per cent 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 Dr Archer.
His co-author, Prof Dijk, told the BBC: “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 in the household.“
Referring to previous studies, he added: “We of course know that shift work and jet lag is associated with negative side effects and health consequences.
“They show up after several years of shift work. We believe these changes in rhythmic patterns of gene expression are likely to be related to some of those long-term health consequences.”