Shift Workers

Working night shifts ‘sends body into chaos’ and could cause lasting damage to health

Sleep researchers found that disruption to natural body clock has ‘severe’ impact on finely-tuned DNA

Adam Withnall 

Tuesday 21 January 2014

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.”

Shift workers more likely to suffer from poor health, including diabetes and obesity

Shift work was defined as being outside the hours of 7am and 7pm

The Health Survey for England found that a third of men and over a fifth of women work irregular hours

Antonia Molloy  published in the Independent

Monday 15 December 2014

Shift work not only disrupts your social life – it also damages your health and makes you fatter, according to new research.

People who work outside “normal” hours are more likely to be obese, suffer from diabetes and be at increased risk of developing mental health problems, compared to those who work between 7am and 7pm, the Health Survey for England found.

The data shows that 33 per cent of men and 22 per cent of women carry out shift work – with 16 to 24-year-olds the most likely to work irregular hours.

Overall, shift workers are more likely to have one or more longstanding illness – 40 per cent of men and 45 per cent of women who work shifts, compared to 36 per cent and 39 per cent respectively who work normal hours.

Additionally, shift workers have an average BMI of27.8kg/m2 for men and women, compared to 27.2kg/m2 for men and 26.8kgm2 for women who do not work shifts.

And 10 per cent of all shift workers have diabetes, while for those who work normal hours the figures are 9 per cent for men and 7 per cent for women. 

The research said that shift work may cause ill health because it disrupts the body’s circadian rhythms (internal clock) by interfering with the production of melatonin, disturbing sleep and causing fatigue. Shift workers also tend to eat a less healthy and balanced diet.

Rachel Craig, research director for HSE, told the BBC that the prevalence of zero-hours contracts could be contributing to an increase in shift work – with devastating consequences for the nation’s health

“It looks as though shift working is slightly higher than in 2009 and that may be a move to more part-time and zero-hours contract working. There is evidence to suggest that may be having an influence.”

Ms Craig added: “If a larger proportion of people are doing shifts it is likely to result in greater demand on healthcare systems. It is something to think seriously about.”

However, the research also found that people from the most deprived households, who may already have higher rates of poor health, are more likely to do shift work.

The report advocates companies implementing polices and recommendations to offset the negative health effects of shift work, and advises employees to lead a healthy lifestyle and regulate sleep patterns.