Insufficient sleep is a ‘public health epidemic’, according to the US Centre for Disease Control and Prevention. The organisation links a lack of sleep with surgical mistakes, car crashes, disease susceptibility and premature death. Now it can add the common cold to that list.
According to research published by the journal Sleep, getting insufficient sleep can increase your risk of catching a cold by a factor of four.
The researchers from three US universities found that people who sleep for more than seven hours are four times less likely to catch a cold when exposed to the virus, compared to those who spend less than six hours in bed a night.
Volunteers underwent two months of screenings and questionnaires to control for external factors such as stress, temperament and drug use.
Their usual sleep habits were measured with a watch-like sensor, before being exposed to the cold virus. They were monitored to see how many of them would become infected.
The researchers found that those who slept too little were 4.2 times as likely to become infected.
The study’s lead author, Aric Prather of the University of California, San Francisco, says that this is the first study of its kind. His research team used objective measures to link sleeping habits and health risks. He says that the findings add to the growing evidence of the importance of sleep for our health.
‘Short sleep was more important than any other factor in predicting subjects’ likelihood of catching cold. It didn’t matter how old people were, their stress levels, their race, education or income. It didn’t matter if they were a smoker. With all those things taken into account, statistically sleep still carried the day.’
Previous studies by Dr Pather have found that vaccines are less effective in people who sleep fewer hours. The researchers involved in this study say that it is more accurate than typical sleep experiments, in which subjects are deprived of rest, because it is based on the volunteer’s normal sleep pattern.