Answer: Try to get a good quality, undisturbed night’s sleep.
A good night’s sleep is where you fall asleep when you want to and then sleep through until when you want to wake up.
A 2009 study measured subjects’ sleep efficiency and duration for two week and then exposed the subjects to the cold virus. The better the subjects slept, the better they coped with exposure to the cold virus.
While both sleep duration and sleep efficiency both predicted cold symptoms, sleep efficiency was the critical factor.
Sleep habits and susceptibility to the common cold.
Source
Department of Psychology, Carnegie Mellon University, Pittsburgh, PA 15213, USA. scohen@cmu.edu
Abstract
BACKGROUND:
Sleep quality is thought to be an important predictor of immunity and, in turn, susceptibility to the common cold. This article examines whether sleep duration and efficiency in the weeks preceding viral exposure are associated with cold susceptibility.
METHODS:
A total of 153 healthy men and women (age range, 21-55 years) volunteered to participate in the study. For 14 consecutive days, they reported their sleep duration and sleep efficiency (percentage of time in bed actually asleep) for the previous night and whether they felt rested. Average scores for each sleep variable were calculated over the 14-day baseline. Subsequently, participants were quarantined, administered nasal drops containing a rhinovirus, and monitored for the development of a clinical cold (infection in the presence of objective signs of illness) on the day before and for 5 days after exposure.
RESULTS:
There was a graded association with average sleep duration: participants with less than 7 hours of sleep were 2.94 times (95% confidence interval [CI], 1.18-7.30) more likely to develop a cold than those with 8 hours or more of sleep. The association with sleep efficiency was also graded: participants with less than 92% efficiency were 5.50 times (95% CI, 2.08-14.48) more likely to develop a cold than those with 98% or more efficiency. These relationships could not be explained by differences in prechallenge virus-specific antibody titers, demographics, season of the year, body mass, socioeconomic status, psychological variables, or health practices. The percentage of days feeling rested was not associated with colds.
CONCLUSION:
Poorer sleep efficiency and shorter sleep duration in the weeks preceding exposure to a rhinovirus were associated with lower resistance to illness.
Read the complete scientific paper: Sleep Habits and Susceptibility to the Common Cold
Or read this newspaper account:Proper snoozes can prevent sneezes, find researchers
How did the researchers assess the subjects’ sleep efficiency?
Each evening, for 14 days, they asked the subjects (among other questions about their previous night’s sleep):
“How many minutes of sleep did you lose between the time you lay down to go to sleep [interviewer stated actual time] and the time you got out of bed [interviewer stated actual time] because you had difficulty falling asleep or you woke up and couldn’t get back to sleep?”
Why might poor quality sleep cause you to catch colds?
Maybe getting a disturbed night’s sleep impairs our immune function. The researchers mentioned earlier studies have shown that sleep deprivation impairs the immune function. But what if the the sleep disturbance? Maybe stress? The researchers asked subjects to rate their perceived stress and adjusted for that possibility in their analysis and still the association between poor sleep and cold symptoms held up. So it does seem that the body wants a quality night’s sleep. If it doesn’t get it, bad things happen!
So if you want to avoid getting a cold, it seems sensible to work on getting a good night’s sleep.
How can you improve the quality of your sleep?
That’s another set of posts. Of the top of my head, I’d suggest trying exploring the obvious culprits:
- cutting out caffeine after lunchtime;
- cutting out alcohol after lunch;
- eliminating anxious thoughts (!);
- not cognitively over-stimulating yourself just before bed;
- have a regular bed-time routine.
