How a good sleep can keep the cold away

You know that lack of sleep can turn you into a groggy snarl-monster ready to snap the head off the first person to question why you are having trouble forming words with more than two syllables. You probably also know (if you read this column regularly) that sleep is necessary for a whole raft of regenerative processes and if you don’t get it the effects are both physical and mental. Now, a new study has highlighted one of those physical effects by showing that lack of sleep dramatically increases your chance of catching a cold.

The study involved volunteers who underwent two months of screening to establish baseline scores for stress, temperament, alcohol, and cigarette use. Then for a week the researchers established the subjects’ normal sleeping habits using subjective reports as well as sensors worn on the wrist that objectively measured sleep quality.

They found that subjects who slept less than six hours per night in the preceding week were 4.2 times more likely to catch a cold than those who slept more than seven hours a night.

Immediately after that week of sleep measurement the subjects were then isolated in a hotel and were inoculated with the common cold virus via nasal drops. The subjects were then monitored for a week with daily mucus samples collected to see if the virus had taken hold.

They found that subjects who slept less than six hours per night in the preceding week were 4.2 times more likely to catch a cold than those who slept more than seven hours a night. Those who slept less than five hours a night were 4.5 times more likely to catch a cold. In fact, lack of sleep was the single biggest factor influencing likelihood of catching a cold outweighing stress levels, smoking status, race, education levels, and income.

Sleep is obviously a crucial factor in health, and in this case it is clearly affecting immune functioning. Thankfully the evidence is that in Australia most adults do get eight hours sleep a night but with so many techno-temptations offering to keep you awake into the wee small hours, it is worth reminding yourself how essential a good sleep really is.