Keeping the 'grave' out of 'graveyard shift'
By Erin Allday
The San Francisco Chronicle
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SAN FRANCISCO — When Debbie Toms first started working nights as a respiratory therapist, co-workers teased her that the graveyard shift would "take 10 years off your life," she said.
It never occurred to her that there might be some truth to the statement.
While Toms has managed to stay healthy in the 30 years that she's worked off and on night shifts, most recently at Kaiser Permanente's Regional Center for Sleep Medicine in San Jose, the graveyard shift has been associated with everything from ulcers and depression to heart disease and cancer. There's even a formal diagnosis called shift work disorder, which applies to people who suffer insomnia and excessive sleepiness from working nights.
"It's not surprising," said Dr. Louis Ptacek, a UCSF neurologist studying genes and sleep behaviors. "We evolved on a planet that is rotating every 24 hours. Our internal clock is more than just when we sleep and wake. It's related to cell division and it regulates our immune systems. When we battle our internal clock, that has complications."
Most researchers — and night-shift employees — agree that a fatigue factor undoubtedly goes along with working the graveyard shift. It's more difficult to get a good night's, or rather day's, sleep, and it can be a challenge to force the mind and body to be at their best in the middle of the night.
Roughly 15 million people, or 15 percent of American workers, regularly work a shift that's outside the typical daytime schedule, according to the U.S. Department of Labor. Studies have shown that between 10 and 20 percent of shift workers have trouble with insomnia when they're trying to sleep and feeling sleepy on the job when they're trying to stay awake.
That leads to the obvious connection between sleepiness and the risk of accident - either on the job or driving to and from work. People who are sleep-deprived can succumb to "microsleeps," where they fall asleep for just a few seconds and don't even realize it, said Dr. Clete Kushida, director of the Stanford University Center for Human Sleep Research.
"Probably the most obvious problems with (night) shift work are cognitive functions, so people have difficulty focusing. They might have problems with irritability and mood fluctuations," Kushida said. "And then there is excessive sleepiness, which can lead to motor vehicle accidents and industrial accidents."
Not everyone agrees that shift work is much of a health concern.
"The data here is not extremely firm," said Dr. Allan Pont, vice president of medical affairs at California Pacific Medical Center, who ran the hospital's residency training program for 20 years. Pont, who has worked many night shifts himself, said he's skeptical of the idea that many health problems are related to work schedule.
"Obviously it's difficult when people change from a day shift to a night shift," he said. "There are those who can adapt to it and those who don't. Those who adapt probably do just fine, and the others quit."
Still, there are dozens of studies that have demonstrated risks associated with the night shift, and the U.S. Centers for Disease Control and Prevention a decade ago released a report to help workers protect themselves.
Last December, the International Agency for Research on Cancer, part of the World Health Organization, listed the graveyard shift as a "probable" cause of cancer. The agency's conclusion followed several studies that have shown higher rates of cancer — breast cancer in particular — among people who work nights.
It doesn't mean the graveyard shift causes cancer, researchers said, but there seems to be an association. One of the possible explanations is that shift work could interrupt the production of the hormone melatonin, which is typically made at night while the body rests. Melatonin can suppress tumor development and growth.
Cancer aside, most of the risks associated with night work are related to a simple lack of sleep and not being able to keep up steady, healthy behaviors - such as eating right and getting exercise. That could explain some studies that show higher rates of cardiac disease and metabolic syndromes in night-shift workers.
According to the CDC report, digestive problems can also arise, either because of poor eating habits or because the digestive organs aren't used to working hard in the middle of the night.
Graveyard workers also tend to be more stressed out from fatigue and from not getting to spend enough time with friends or family, doctors say. That stress could play a role in higher rates of ulcers and high blood pressure.
"A reasonable percentage of Americans work a night shift, and a majority of them have health issues related to it," said Dr. Sunil Rama, medical director of the Kaiser sleep lab. "It's been linked to arteriosclerosis, headaches, insomnia, excessive sleepiness. You ask anyone who's worked nights, and they're usually a wreck the next day."
Focus on internal clock
The focus of much research on shift work disorder is on the circadian rhythm — the body's internal clock that keeps everyone on roughly a 24-hour schedule. It's possible, doctors say, for people to alter their circadian rhythm so that they are perfectly healthy and comfortable working a night shift regularly.
The problem is that humans are accustomed - both by societal pressures and centuries of evolution — to sleeping at night and being active during the day. Very few people want to live on a permanent schedule that has them sleeping away the daylight hours. Instead, most people who work a regular night shift end up throwing their clock off every weekend when they try to adjust to the rest of society.
"If you can get the person to stay on the schedule seven days a week, they're usually OK. But who wants to live their life at night on their days off? What about their vacations?" said Rama.
Toms said that after 30 years of off-and-on graveyard duty, she's adjusted pretty well to her overnight shifts. The key to staying healthy, she said, is to prioritize.
Sleep is crucial. To make sure she gets enough sleep, Toms has bedtime rituals that help her unwind. She typically gets off a night shift at around 6:30 a.m. and drives home wearing dark glasses - bright light generally stimulates the body to stay awake despite the exhaustion.
At home, Toms takes care of any potential disturbances - she feeds the cats, turns off the phone, closes dark blinds in her bedroom. Sometimes she'll have a small snack, but usually it's just some tea.
She usually sleeps until about 3 p.m., then has breakfast. She'll get some light exercise like yoga - she saves the active workouts for days she doesn't work. Lunch is at 9 p.m., dinner at 3 a.m.
"You have to really be aware of your health - am I eating well, am I sleeping enough, am I exercising?" Toms said. "It just takes planning. You have to realize this is your lifestyle and be ready for it."
Tips for staying healthy
— Those who work five nights a week should stick close to the same schedule on days off.
— Try to go to bed as soon as possible after getting off work.
— Set up a bedtime routine - something to signal to the body that it's time to sleep. That could mean making a cup of tea or taking a hot bath or shower.
— Wear dark sunglasses when leaving work in the morning.
— Use window coverings that block out all light. Sleeping masks also can help.
— Get rid of noisy distractions.
— Make time for exercise.
Copyright 2008 The san Francisco Chronicle