Shift Workers With Irregular Sleep Patterns at Increased Risk for Cancer

Healthcare workers, flight attendants, firefighters and 24-hour store clerks beware: frequently shifting sleep schedules, like those adopted by employees with irregular working hours, may lead to serious health risks, new research suggests.

Though more testing on humans is needed, recent analysis on mice is raising concerns about the level of harm shift work may do to a person's health, BBC News reported.

Researchers say mice that slept irregularly ended up weighing 20 percent more than others despite eating the same amount and type of food, pointing to irregular sleep as a potential contributor to obesity.

And to investigate the impact of disrupted sleeping patterns on cancer development, scientists pushed back the body clocks of mice at risk for breast cancer by 12 hours weekly for a year. The results are rather alarming: tumors didn't appear in mice after 50 weeks as they were supposed to, but showed up 8 weeks earlier. 

Experts say that while plenty of other factors — such as social class and activity level — should be taken into account when assessing risks for cancer and obesity, the research team behind this latest study warns that disrupting the body's internal rhythms could potentially be dangerous.

"If you had a situation where a family is at risk for breast cancer, I would certainly advise those people not to work as a flight attendant or to do shift work," Gijsbetus van der Horst, one of the team's researchers, said.

The Centers for Disease Control and Prevention recommends all people, regardless familial cancer history, go to bed around the same time each night and rise at the same time in the morning to contribute to healthy sleep habits.