A Canadian study by researchers from the Queen’s Cancer Research Institute (Canada), the University of British Columbia and Drexel University published in the journal “Occupational and Environmental Medicine” followed women working at night for 30 years.
They wanted to understand the links between the reduction of melatonin (the sleep hormone that protects against cancer), daylight and the increase in the osteogenic hormone, responsible in the development of breast cancer.
Their research involved 1,134 women (between 20 and 80 years old) with breast cancer, from different professions. A control group of 1,179 non-cancerous women was also formed.
Night work is bad for your health
Women who have worked at night for less than 29 years do not have an increased risk of breast cancer, while those who have worked at night for 30 years or more have a more than double risk of breast cancer. The conclusions are similar according to the night occupations.
Previous studies had already shown that 3-8s disrupted the health of workers. This pace of work requires a break in the biological clock and sleep. Which according to the International Cancer Research Center (Lyon) are “ probably carcinogenic to humans “.
This study therefore confirms the link between interfering long-term labor and an increased risk of breast cancer. Altering melatonin levels may increase cancer risk through its involvement in estrogen production.
The researchers also conclude that “ further research is therefore still needed to determine how disruption of the sleep cycle affects the hormones involved in certain breast cancers. “.
