Night Shift Ruins the Body’s Cycle
For some workers, the night shift is inevitable. Previous studies have tied the night shift to an increased rate of heart attacks, cancer and type 2 diabetes. In a new study, researchers from the Sleep Research Center in Surrey, England examined the long-term effects that working a night shift might have on the body. They reported that people who work at night are more likely to have bodies that are "in chaos."
"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," researcher Prof Derk-Jan Dijk said reported by BBC News.
For this research study, the team recruited 22 workers. The workers had moved from working a normal shift to working the night shift. They were asked to turn off their lights four hours earlier than usual, which altered their normal timing by 12 hours. The researchers collected blood samples throughout the study.
From the samples, the researchers had a total of 1,396 genes to test. 40 genes from this set revealed some kind of change in gene expression that affected the genes' activity time. 180 of the genes also became erratic. The researchers concluded that the genes of people who worked night shifts no longer functioned in the same way. The researchers explained that around six percent of genes are timed to either be more or less active throughout the day at specific times. When people worked the night shift, that timing gets disrupted.
"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 Dr. Simon Archer, one of the researchers at the University of Surrey. "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."
The study was published in the Proceedings of the National Academy of Sciences.