US scientists suspect that a good night’s sleep is crucial for the body’s immune defences. People who get too little sleep are more likely to catch a cold, study finds.
Those who slept six hours a night or less were four times more likely to catch a cold when they were exposed to the virus than people who spent more than seven hours a night asleep, their study found.
“It goes beyond feeling groggy or irritable,” said Aric Prather, a health psychologist at the University of California in San Francisco. “Not getting enough sleep affects your physical health.”
The scientists recruited 94 men and 70 women, with an average age of 30, for the study and subjected them to two months of health screening, interviews and questionnaires to establish their baseline stress levels, temperament and usage of alcohol and tobacco. The volunteers then spent a week wearing a wrist-mounted sleep sensor that tracked the duration and quality of their sleep each night.
To see how well they fought off infections, the participants were taken to a hotel and given nasal drops containing the cold virus. Doctors monitored them closely for a week after, collecting mucus samples to work out if and when the virus took hold.
The researchers found that the less sleep people got, the more likely they were to develop a cold. Those who got less than six hours of sleep a night were 4.2 times more likely to fall victim to the bug than those who slept more than seven hours. Those who slept less than five hours had a 4.5 times greater risk.