People who get less than 7 hours of sleep per night are 3 times more likely to catch a cold than those who rack up 8 or more, according to a study in the Archives of Internal Medicine.
Sheldon Cohen and colleagues at Carnegie Mellon University recruited 153 healthy adults and paid them $800 if they’d agree to have rhinovirus sprayed up their schnozz and wait to see what happened.
The scientists had obtained detailed sleep histories for each participant before the experiment began.
Five days after the rhino-squirt, immunologic testing revealed evidence of rhinovirus infection in 135 of the participants, yet only 54 developed symptoms of a cold.
The correlation between sleep duration and risk of getting sick was independent of known risk factors such as lack of exercise, stress and smoking.
Cold symptoms are caused by the body’s response to the virus, not the virus itself according to Cohen. People who make just the right amount of anti-virus proteins called cytokines can handle the infection without symptoms.
Those who overproduce cytokines develop the clinical syndrome. Sleep, says Cohen, probably helps the body fine-tune its immune response.
Prior studies have linked lack of sleep to coronary artery disease, weight gain, stroke and high blood pressure, not to mention grouchiness.