Five Years of Night Shift Work Elevate a Person’s Risk of Death

Working inconsistent hours is bad for your health, according to researchers who studied 75,000 U.S. nurses

Ambulance on the Night Shift
Nurses who work rotating shifts are at greater risk of dying from cardiovascular disease and lung cancer than workers who stick with a nine-to-five schedule. ERproductions Ltd/Blend Images/Corbis

Working a night shift won't just throw your entire day out of whack: it can also damage your health.

Studies have long shown that shift workers, including those who work at night, suffer from a 40 percent higher risk of cardiovascular disease plus boosted rates of diabetes and obesity. They also have a greater chance of developing depression or sustaining an on-the-job injury. The World Health Organization has even dubbed shift work a likely carcinogen.

Now, new research indicates that inconsistent hours can cut your life short. A new study in the American Journal of Preventive Medicine, which crunched data from 75,000 American nurses over a 22 year period, showed that those who worked in rotating shifts were more likely to die during the course of the study.

Shift work increased the risk of death from any cause by 11 percent in nurses who worked rotating shifts for at least five years. The nurses’ risk of dying from cardiovascular disease shot up by about 19 percent after five years, too. The research also revealed a 25 percent increase in the risk of dying from lung cancer for those who worked rotating shifts for 15 years or more.

Many of these problems arise because staying up all night and fragmented sleep wreck havoc on our circadian rhythms, according to Cleveland Clinic sleep expert Tina Waters:

Most of us are awake during the day because our body’s internal clock is keeping us awake. So no matter how tired you are after working all night, your awakening signals will conflict with your desire to sleep.

Researchers are still investigating the exact mechanisms by which damage occurs when we mess with our sleep cycle. In the meantime, there are 8.6 million people in the U.S. who work either overnight or rotating shifts, according to WebMD. There’s only so much that these workers can do to minimize the risks associated with their work schedules, but getting the best possible sleep by blocking out daylight and minimizing use of electronics before bed are good strategies to start with.

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