The study, which was recently published in the journal Current Biology, involved an examination of mice. The mice had their sleep schedules disturbed.
The result: the mice whose sleep times were thrown off were 20 per cent heavier than other mice. More importantly, their chance of developing cancer went up.
Specifically, researchers found that mice who normally developed breast cancer had cancerous tumors appear after 50-weeks. However those who had their sleep schedules disrupted saw those tumors appear roughly 8-weeks earlier.
“This is the first study that unequivocally shows a link between chronic light-dark inversions and breast cancer development,” the report said.
It’s still too difficult to tell how the results can be linked to humans. But researchers speculate that it could mean an extra eight pounds and the development of breast cancer five years earlier than normal.
One takeaway lesson, according to researcher Gijsbetus van der Horst: women with elevated risk of breast cancer should never perform shift work. “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,” van der Horst said.
The study will add to a growing body of evidence which suggests that shift work is dangerous for one’s health–as dangerous, perhaps, as drinking excessively or smoking cigarettes.
