In the U.S., about 8.6 million people perform shift work, whether they have
a night job or rotate shifts during the week. For many, it's a rite of passage
in their careers; for others, it's a financial necessity. But there's a growing
sense that shift work could be taking a serious toll on their health.
"There is strong evidence that shift work is related to a number of serious
health conditions, like cardiovascular disease, diabetes, and obesity," says
Frank Scheer PhD, a neuroscientist at Harvard Medical School and Brigham and
Women's Hospital in Boston. "These differences we're seeing can't just be
explained by lifestyle or socioeconomic status."
Even as a child I hated waking up early in the morning. Something about
being startled out of a deep sleep by a clanging alarm made me feel disoriented
and lonely. Alas, now, as a working mother, I often have to wake early -- to
fit in a workout, check business emails, or make preparations for my children's
I still don't like it.
For many of us, getting up before we would naturally is painful -- because
it's too early, too sudden, or too dark. Is there a path to kinder, gentler
Shift work is also linked to stomach problems and ulcers, depression, and an
increased risk of accidents or injury.
The Many Faces of Shift Workers
According to the National Sleep Foundation, a shift worker is not just
someone who works nights, but anyone who works outside a steady 9 to 5
The millions of shift workers in the U.S. include police officers,
firefighters, nurses, doctors, pilots, waitresses, truck drivers, and many more
professionals. Even a personal trainer who works out at the gym with clients in
the early mornings and evenings is a shift worker.
As shift work has become more widespread in the U.S., the health risks have
become a focus both for researchers and for the businesses that employ shift
workers. How serious are those dangers -- and can they be reduced?
Unfortunately, we don't have all the answers yet.
How Does Shift Work Affect Us?
Experts say that shift work could have a serious impact on our health in at
least two ways. Some of it may have to do with the lifestyle that shift work
encourages. The rest has to do with our biology.
In terms of lifestyle, working odd hours leads to some obvious problems.
People who do shift work tend to have sleep disturbances and sleep loss. They
might feel isolated, since their jobs cut them off from their friends and
families. They might find it harder to exercise regularly, and may be prone to
eat junk food out of a handy vending machine, says Scheer.
But Scheer and other experts believe a significant part of the problem with
shift work is physiological. On a fundamental level, being awake at odd or
irregular hours fights with our biological rhythms. Shift work disrupts the
circadian rhythm -- our internal body clock that is keyed to natural daylight
Because circadian rhythm affects how the body functions, disrupting it can
throw everything out of whack -- including our cardiovascular system,
metabolism, digestion, immune system, and hormonal balance. That appears to
have serious consequences.
Short-Term Health Effects of Shift Work
The short-term health effects of shift work are clear. Even if you're not a
shift worker yourself, you've probably experienced the equivalent effects --
maybe after a transatlantic flight, an all-nighter in college, or a few nights
with a wailing newborn. Aside from the obvious fatigue, effects include:
Gastrointestinal symptoms like upset stomach, nausea, diarrhea,
constipation, and heartburn