By Amir Khan for U.S. News
Working nights is tough. Sleeping when the sun is out and working when it's dark can take a real toll on your sleep schedule, but did you know it could affect way more than just your Zzs? The 15 million Americans who work nights are at high risk of developing several chronic conditions -- but the good news is that sleep experts say it's possible to combat this risk without quitting your job.
Working nights can interfere with the circadian rhythm, your internal clock that helps regulate metabolism, hormones and other biological processes. Your circadian rhythm is regulated in part by sunlight, and when you have to sleep during the day, it throws your rhythm off and leads to less sleep and less quality sleep, says Barbara Phillips, medical director of University of Kentucky's sleep lab. "Shift workers have consistently been demonstrated to get one to three hours less sleep in a 24-hour period than non-shift workers, and the sleep they do get may be more fragmented and of poorer quality," she says. "Plus, being awake in the dark and trying to sleep during the day affects secretion of many hormones and chemicals, and this disruption may be part of the problem as well."
This lack of sleep and hormone disruption puts you at risk of a host of health issues, Phillips says. "Shift workers have an increased risk of obesity, cancer, prostate for men, breast [cancer] for women, ulcers, pregnancy complications, diabetes and heart disease," she says.
One of the strongest ties is between night shift work and breast cancer. A 2012 study published in the journal Occupational and Environmental Medicine looked at 18,500 Danish women who worked nights between 1964 and 1999, and found that working nights increased the women's risk of developing cancer by 40 percent.
There is also an increased risk of diabetes that comes with working the night shift -- a 2013 study published in the journal Occupational and Environmental Medicine found that shift work was associated with a 9 percent increased risk of diabetes, primarily due to the poor eating habits and metabolism changes that come from working overnight.
Working the night shift doesn't just come with physical effects, says Stephanie Dailey, an assistant professor of psychology and behavioral sciences at Argosy University in Arlington, Virginia, but mental and emotional effects as well. "When you work nights, you develop a feeling of restlessness, like you're constantly walking around jetlagged," she says. "You experience a decreased ability to pay attention, which is a problem because a lot of these jobs require precision, and having a decreased cognitive ability really inhibits your job function."
A 2012 study in the journal Academic Emergency Medicine administered several cognition tests to emergency department physicians before and after their shift. One of the tests focused on how well they could recall words. The researchers found that after the night shift, doctors could remember significantly fewer words compared to the doctors who worked a day shift. They also reported poorer sleep quality.
Night shift workers also report higher levels of stress, Dailey says, which comes with its own set of problems. "We don't perform as well under stress," she says. "People that work the night shift report higher instances of anxiety, depression, relationship problems. What that boils down to is that we're kind of cut off from friends and family, so we feel isolated."
So how do you reduce your risk? Changing to a daytime shift is best, but that's not always possible, Dailey says. Instead, start by trying to reset your circadian clock. "Try to stick to a regular sleep cycle," she says. "Go to bed and wake up at the same time every day, even when you're off."
Next, try to avoid the "seesaw approach" to working - which may involve speaking to your boss about your hours. "Try to avoid working a few days on the night shift then a few days on the day shift," Dailey says. "If you can, try to work the same shift every day."
You can also try to fix your melatonin levels, Phillips says. Melatonin is a hormone produced by exposure to sunlight that regulates sleep, and night workers tend to produce lower levels. "Melatonin appears have a role in cancer, so this reduction in melatonin secretion could be part of the reason for the increased cancer risk in shift workers," Phillips says. "Taking melatonin, 3 milligrams at night, may improve sleep length and quality after a night shift."
Two prescription drugs, modafinil and armodafini, are available for increasing alertness for night workers, but Phillips says she doesn't recommend them due to cost and side effects, which include hallucinations and depression. Instead, Phillips recommends coffee and naps during the day -- and avoiding medication to help you sleep. "Sleeping pills do not improve sleep length or quality after a night shift, and I do not recommend them," she says.
The key to surviving the night shift is to just take care of your body, Dailey says. If you don't do that, you'll never feel well, no matter how much melatonin you take or how much you try to reset your circadian clock. "It's all a domino effect," she says. "Night work leads to poor decision-making, which means we don't make good decisions on what to eat. This impacts our health and puts us at risk for chronic conditions."
Ultimately, not everyone who works the night shift will develop these health conditions, Phillips says. But, she asks, is it really worth the risk? "There are definite biologic and genetic variations in human tolerance to night work and to sleep deprivation," Phillips says. "A few individuals may actually do quite well with shift work, but most will not, and a few will really suffer."