ATLANTA (CBS Atlanta) — Poor sleeping patterns could be a contributing factor to cancer, a new test on mice suggests.
BBC News reports the new research highlights concerns about the detrimental effect shift work may have on an individual’s health.
Researchers warn that though further testing on humans is needed, women with a family history of breast cancer should avoid working shifts that contribute to poor sleep patterns. The study also found that the mice with poor sleeping patterns were 20 percent heavier, despite consuming the same diet as the other mice.
Previous studies in people have indicated that shift workers and flight attendants have a higher risk of diseases like breast cancer.
Experts say the apparent link could be attributed to several factors, including the disruption of the body’s internal rhythm, more commonly referred to as the “body clock.” However, they warn that any link at all needs further research and that the cancer development could be due to other factors such as social class and activity level.
For the study, mice at risk of developing breast cancer had their body clock pushed back by 12 hours every week for a year. The mice would normally have tumors after 50 weeks, but the tumors appeared eight weeks earlier with regular disruption to their sleeping patterns.
Centers for Disease Control and Prevention notes that insufficient sleep and sleep disruption is considered a public health epidemic. CDC recommends people go to bed around the same time each night and rise at the same time in the morning to help build healthy sleep hygiene.
“This is the first study that unequivocally shows a link between chronic light-dark inversions and breast cancer development,” the report said.
Researchers suggest that the effect on humans could be at-risk women getting cancer five years earlier or extra weight gain of eight pounds, though they note it’s hard to say for certain.
“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.
Dr. Michael Hastings, of the United Kingdom’s Medical Research Council, told BBC that the study offers definitive experimental proof in the acceleration of breast cancer.
“The general public health message coming out of my area of work is shift work, particularly rotational shift work is a stress and therefore it has consequences… There are things people should be looking out for – pay more attention to your body weight, pay more attention to inspecting breasts, and employers should offer more in-work health checks,” Hastings said.
The study is published online in New Biology.