An analysis of data from the world’s largest and longest-running study of women’s health found that rotating night shift work is associated with higher death rates.

The international team of researchers investigated possible links between rotating night shift work and all-cause, cardiovascular disease, and cancer mortality in a study of almost 75,000 registered US nurses. Using data from the Nurses’ Health Study (NHS), the authors analysed 22 years of follow-up.  Reporting in the American Journal of Preventive Medicine, they conclude that all-cause and cardiovascular disease-related mortality were significantly increased among women who worked more than five years of rotating night shifts when compared to those who never worked the night shift.

In addition, the study found that working 15 or more years of rotating night shifts was associated with a modest increase in lung cancer mortality.

Fangyi Gu, Jiali Han, Francine Laden and others. Total and Cause-Specific Mortality of US Nurses Working Rotating Night Shifts, American Journal of Preventive Medicine, published online ahead of print, 5 January 2015. DOI: http://dx.doi.org/10.1016/j.amepre.2014.10.018. Risks 685.