Women who regularly work the night shift in Europe and North America may face a 19 percent higher risk of cancer than those who work during the day, said a study Monday, reported AFP.
These heightened risks were not apparent among female night-shift workers in Australia and Asia, said the meta-analysis in the journal Cancer Epidemiology, Biomarkers and Prevention.
“Our study indicates that night shift work serves as a risk factor for common cancers in women,” said study author Xuelei Ma, an oncologist at the West China Medical Center of Sichuan University in Chengdu, China.
“We were surprised to see the association between night shift work and breast cancer risk only among women in North America and Europe,” he added.
“It is possible that women in these locations have higher sex hormone levels, which have been positively associated with hormone-related cancers such as breast cancer.”