MONDAY, Jan. 5, 2015 (HealthDay News) -- Working rotating night shifts may pose a threat to your health, a new study suggests. 
 
 The study defined rotating shift work as at least three nights spent working each month, in addition to days and evenings worked in the month. 
 
 In the new study, researchers led by Dr. Eva Schernhammer of Harvard Medical School tracked 22 years of data from about 75,000 nurses across the United States. 
 
 While the study couldn't prove cause-and-effect, it found that people who worked rotating night shifts for more than five years had an 11 percent increased risk of death from all causes. 
 
 The risk of death from heart disease was 19 percent higher among those who worked such shifts for six to 14 years, and 23 percent higher for those who worked such shifts for 15 or more years, Schernhammer's group found. 
 
 Nurses who worked rotating night shifts for 15 or more years also had a 25 percent higher risk of death from lung cancer, according to the study. 
 
 The findings are to be published in the March issue of the American Journal of Preventive Medicine. 
 
 According to the study authors, prior research has shown that night shift work is linked with an increased risk of cardiovascular disease and cancer. 
 
 "These results add to prior evidence of a potentially detrimental relation of rotating night shift work and health and longevity," Schernhammer, an associate professor of medicine at Harvard and associate epidemiologist at Brigham and Women's Hospital in Boston, said in a journal news release. 
 
 Further research is needed to learn how individual traits might interact with rotating night shift work to harm health, she added. ||||| While working the night shift has been previously associated with higher risk for cardiovascular disease and cancer, a new study also links it to a higher risk in women for all-cause and cardiovascular disease mortality, as well as lung cancer mortality. 
 
 The study, published in the American Journal of Preventive Medicine, found that women working rotating night shifts for five years or more appeared to have a modest increase in all-cause mortality and fatal cardiovascular disease. The study also found that women with 15 years or more of rotating night shift work appeared to have a modest increase in lung cancer mortality, according to a press release. 
 
 The study focused on nearly 75,000 registered U.S. nurses, and analyzed 22 years’ worth of follow-up data compiled by the Nurses’ Health Study. Mortality from all causes appeared to be 11 percent higher for with six to 14 years of rotating night shift work, and death from cardiovascular disease appeared to be between 19 and 23 percent higher. 
 
 While the researchers found no association between rotating shift work and any cancer mortality, they did find a 25 percent increase risk for lung cancer in those who worked a rotating night shift for 15 or more years, according to the news release. 
 
 “These results add to prior evidence of a potentially detrimental relation of rotating night shift work and health longevity,” said Eva Schernhammer, associate professor of medicine at Harvard Medical School and associate epidemiologist at Brigham and Women’s Hospital. 
 
 “To derive practical implications for shift workers and their health, the role of duration and intensity of rotating night shift work and the interplay of shift schedules with individual traits (e.g., chronotype) warrant further exploration,” she said. 
 
 The study identified rotating shift work as working at least three nights per month in addition to days or evenings in the same month.
– Working the night shift has already been linked to higher risks of cancer and cardiovascular disease. Now researchers at Harvard—who've combed through 22 years of data tracking 75,000 nurses in the US—write in the American Journal of Preventive Medicine that rotating night shifts for five or more years results in higher mortality rates in women. Specifically, death from cardiovascular disease is as much as 23% higher and death from lung cancer is as much as 25% higher, reports Fox News. "These results add to prior evidence of a potentially detrimental relation of rotating night shift work and health and longevity," the lead researcher says. Rotating shift work is defined as working at least three nights a month in addition to working day and evening shifts. And while the researchers acknowledge that more study is needed to learn how a person's individual traits might play a role, people who work rotating night shifts for more than five years do experience an 11% hike in risk of death from all causes, reports HealthDay News. (Researchers blame the disrupted balance of light and dark in the increased cancer rates.)