Researchers have warned that night shifts throw the body ‘into chaos’ and could cause long-term damage.
Scientists at the Sleep Research Centre in Surrey said that the scale, speed and severity of damage caused by wakefulness at night was a surprise.
They said that night work has profound effects on the body, altering everything from hormones and body temperature to athletic ability, mood and brain function.
The study followed 22 people as their bodies shifted from normal patterns to those of night workers.
Blood tests revealed that 6% of genes were precisely timed to be more or less active at specific times of the day. This fine-tuning was lost once night work commenced.
Researcher Professor Derk-Jan 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."
Shift work has previously been linked to higher rates of type 2 diabetes, heart attacks, obesity and cancer.