You know all those old wives’ tales and remedies that center around the common cold? Things like ‘If you don’t dress warmly, you’ll catch a cold,’ or ‘If you don’t wear socks you’ll catch a cold,’ or my personal favorite from my grandmother — ‘If you don’t get enough sleep you’re going to get run down and catch a cold.’ As it turns out, that last one is absolutely true. Sorry for making fun of you, Grandma.
The discovery that Grandma was right comes from research done by a group of scientists at Carnegie Mellon University, who took the unprecedented step of purposely exposing a group of intrepid volunteers to a cold virus after conducting surveys about their sleep quantity ad quality. The test yielded results that showed that sleeping less than seven hours a night left participants at three times the risk of getting sick. The researchers have theorized that the immune system is actually impaired when the body doesn’t get the rest it needs and is thus unable to fight illness effectively.
The study, which was published in the journal Archives of Internal Medicine, supports previous research that also showed that sleep quantity and quality has an impact on the incidence of heart disease, with those who sleep seven to eight hours per night having the lowest risk. The actual research involved over 150 volunteers who were all healthy men and women with an average age of 37. They were asked about their sleeping habits over a two week period, then put into isolation and submitted to having a cold virus administered to them via nasal drops. They were monitored for five days, with mucus samples swabbed and signs of illness recorded, and blood samples were taken from each for the following four weeks to identify the presence or absence of antibodies in their system. The end result showed that the less sleep the person had, the higher the likelihood that they would get sick.
Tellingly, the impact of sleep was not restricted to quantity – the quality of sleep that each individual had reported also played a role, with those who indicated extensive time spent in bed awake having a higher likelihood of getting sick. The scientists believe that when sleep is disrupted or of low quality, the immune system is unable to properly regulate the chemicals that it produces to protect us. According to Professor Ron Eccles, director of the Common Cold Centre at the University of Cardiff, “The immune system may control the sleep-wake pattern and lack of sleep or sleep disturbance may depress the immune response to infection. I do believe there is enough information on this to indicate that lack of sleep or sleep disturbance will reduce our resistance to infections such as colds and flu.”