If you sleep less than seven hours a night, you’re far more likely to develop a cold than those who slept eight hours or more.
Even more powerful, if your sleep isn’t “efficient,” you are more likely to develop a cold. Sleep efficiency is the percentage of time you actually spend asleep while lying in bed. If you have less than 92 per cent efficiency, you’re 5.5 times more likely to get a cold.
The study, conducted in Pittsburgh, involved 153 healthy men and women from age 21 to 55. For two weeks, they were asked to keep track of their sleep efficiency and length. They were given nasal drops infected with the cold virus. Thirty-five per cent of them developed a cold that was clinically detected and another 43 per cent had milder cold symptoms. Those who slept less than seven hours a night were almost three times more likely to develop a cold than those who slept eight hours or more.
Dysfunctional sleep is thought to have an effect on the body’s ability — at the molecular level — to fight against an invader such as the cold virus.
The study was published in the Archives of Internal Medicine on Jan. 12.
