While most Americans are curled up in the safety of their bed, one group of workers are just heading out to begin their ‘work day,’ working the ever-dreaded night shift. In fact, according to data compiled by the Bureau of Labor Statistics in 2004, nearly 15 million Americans were working full time on night shifts, evening shifts, rotating shifts or some other form of an irregular schedule.
It has long believed that while difficult at first, our bodies will eventually adjust to the schedule of these late-night shifts so long as we ensure that we are getting our sleep at other times throughout the day. Experts are now saying that this isn’t the case.
In a study published in a 2015 issue of the ‘American Journal of Preventative Medicine,’ researchers studied 75,000 female nurses in the United States over the course of 22 years. The data that they collected, including an interview conducted with each nurse every other year. They compared the data regarding their work schedules over this time with their health, well-being, and lifespan, and their conclusions were shocking.
The study found that of the women who worked rotating night shifts for 6 years or longer, 11% experienced a shortened lifespan. It was also found that night shifts increased the risk of death by cardiovascular disease, with those working these shifts for 6-14 years seeing a 19% increase in their risk whereas those who worked them for 15 years or longer seeing a 23% increase.
Eva S. Shernhammer, MD, DrPH, an associate professor of medicine at Harvard Medical School advised, “These results add to prior evidence of a potentially detrimental relation of rotating night shift work and health and longevity. 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 schedule with individual traits (e.g., chronotype) warrant further exploration.”
The cardiovascular risk is only one of a number of health concerns that have been associated with working these night shifts. Experts also caution about an increased risk of diabetes, obesity, and cancer, along with cognitive impairments, such as memory problems.
In addition to the risks that we are putting ourselves at by working these shifts, many jobs also put others at risk. Truck drivers who drive overnight shifts risk the others on the roadways, while doctors and nurses put their patients at risk as the stresses of night shifts begin to set in.
The good news is that there is evidence that at least some of these effects are reversible. In one study it was found that those who stopped working night shifts were able to recover their lost cognitive functions after a period of approximately 5 years.