Night Shift Work May Cause Cancer

Working the night shift may cause cancer, according to a report published in The Lancet.
The report comes from a team of 44 scientists in ten countries commissioned by the World Health Organization's International Agency on Cancer Research.
They report "limited" evidence of a connection between cancer and night shift work in people. That evidence included a higher rate of breast cancer in female nurses who work night shifts.
But those studies, which were observational, don't prove cause and effect. Many genetic and environmental factors affect cancer risk.
So the scientists also reviewed studies in which animals were exposed to light at night, disrupting the animals' so called body clocks (circadian rhythm).
Those studies provided "sufficient evidence" of a connection between circadian rhythm disruption and cancer, states the report.
The scientists noted that shift work may raise cancer risk suppressing production of melatonin, a chemical involved in the circadian rhythm.

source: women's journal by Miranda Hitti