MONDAY, March 7 (HealthDay News) -- Sleep tight, but not right
after looking at something bright.
That's the message of a new survey that suggests many Americans
might be losing valuable shut-eye because they spend the hour
before bedtime in front of the electronic glow of a television,
cell phone or computer.
The survey doesn't prove that exposure to bright light before
bed disrupts sleep. But some experts recommend an "electronic
curfew" an hour before bedtime, when people should dim lamps and
avoid checking their e-mail or watching late-night TV.
"Falling asleep isn't like flicking a switch. We don't put our heads on the pillow and fall off to sleep," said Allison G. Harvey, a sleep specialist and professor of psychology at the University of California at Berkeley. "We take time to wind down at night. If we've got bright light conditions, we're not giving ourselves a chance to get off to sleep and stay asleep."
The National Sleep Foundation's annual
Sleep in America poll, whose results were released Monday,
surveyed 1,508 people between the ages of 13 and 64.
Overall, the survey suggests that a majority of Americans aren't
getting enough sleep: 63 percent said their needs aren't being met
during the week.
Ninety-five percent of those surveyed said they'd used an
electronic device -- such as a television, computer, video game or
cell phone -- within the hour before bed at least a few nights a
week. About two-thirds of people aged 30 to 64 frequently watch TV
in the hour before bed, but only about half of younger people do.
Not surprisingly, those under 30 are much more likely than older
people to send or receive text messages on their cell phones in the
hour before bed.
The problem is that light exposure before sleep can disrupt body
rhythms and suppress the release of the hormone melatonin, which
promotes sleep, Harvey explained.
But does it actually hurt sleep? Harvey said the survey doesn't
prove that. Still, she suspects exposure to light is a problem. "No
one's proven it yet, but it seems more than tempting to speculate
fairly strongly," she noted.
Dr. Matt Travis Bianchi, a sleep specialist at Harvard Medical
School in Boston, said the issue of light before sleep is
complicated: not all kinds of light activate body cycles in the
same way, and a little bit of light -- such as from a TV at a
distance -- might still cause a problem.
Also, "we are
very different in our sensitivity to light," he added. "I
have on rare occasions had patients who were 'light-toxic,' in that
if they got bright light late at night they couldn't sleep at all.
Contrast that with patients I have who sleep with the light and TV
on routinely, and don't have much problems that they can feel."
What can people try to do to sleep better?
Harvey recommends an electronic curfew. Also, "try to stick to a
fairly regular wake time, get bright light in the morning and dim
light at night, exercise regularly and have a bedtime routine of 30
to 60 minutes when you're letting yourself wind down," she
suggested.
If you don't sleep well but can't bear to tear yourself away
from the TV or computer before going to bed, Bianchi recommends
trying a pair of "dampening glasses," which will filter out the
most damaging light. You can try them, he said, and see if they
make a difference.
He also said people should be aware that it may not be the light
of a cell phone or computer that triggers sleep problems. It could
be the anxiety produced when you, say, read an e-mail that makes
you angry.
More information
For more about
understanding sleep, try the U.S. National Institute of Neurological Disorders and Stroke.