by Melaina Juntti
Sleep and Sickness
A new study proves that the number on defense
against colds is getting enough sleep. Although doctors have long known
that lack of sleep can make you more prone to illness, a pivotal
new study proves
just how crucial sufficient shuteye really is. After being exposed to
the common cold virus, healthy adults who regularly got less than six
hours per night were four times more likely to actually get sick than
those who slept seven hours.
While most sleep studies have participants self-report their sleep
patterns, which is notoriously inaccurate, this trial was far more
advanced. For one week, 164 otherwise healthy men and women, average age
30, wore a FitBit-like wrist sensor at home while they snoozed. This
measured their sleep quality and duration and provided the researchers
with a picture of what a normal week of sleep looked like for these
folks. Next, they were quarantined in a hotel and given nasal drops
laced with rhinovirus. Then every day for the following week, the
researchers collected mucus samples to determine, via the number of
antibodies present, whether the infection had taken hold. To gauge cold
symptoms, they also measured the volunteers' levels of congestion and
collected and evaluated every tissue they blew their noses on throughout
the week.
Of the participants who'd slept at least six hours per night the week
prior to being exposed to the virus, only 18 percent actually got sick.
By contrast, 39 percent of those who logged less than six hours wound
up with a cold. Looking at the data another way, the researchers
determined that if you sleep seven or more hours per night and you
become exposed to the virus, your odds of catching the cold are only 17
percent. The risk jumps up to 23 percent if you get six to seven hours
of sleep, 30 percent if you log five to six hours, and a whopping 45
percent if you sleep for less than five.
"What can I say? Sleep is a hugely important health behavior and one
that's oftentimes neglected," says study author Aric Prather, a
psychiatry professor at the University of California, San Francisco.
"Sleep bolsters the immune system in several ways. When you're deprived,
T cells — the body's army against viruses — don't proliferate.
Inflammation also increases throughout the body." Prather says these
results also prove that insufficient sleep influences cold
susceptibility more so than body weight, age, smoking, and even excess
stress.
Lack of sleep is a chronic problem for too many of us. According to a
recent National Sleep Foundation survey, American adults average just 6
hours and 31 minutes of shuteye on workdays, while the amount needed to
function optimally is 7 hours, 13 minutes. Sixty-nine percent of us get
less sleep than we need during the workweek; 42 percent don't even
sleep enough on the weekends.
"Sleep too often takes back seat to nutrition, exercise, and other
healthy behaviors we spend time investing in," Prather says. "After we
fill up our whole day, we allocate whatever time is left over for sleep —
and studies like this show that's a big detriment to our health."
