London - A lack of sleep will certainly make you grumpy – but scientists have found it could also give you a cold.
People who sleep for less than six hours are four times more likely to catch a cold than those who get seven hours or more.
Although the importance of a good night’s sleep has been overlooked by many doctors for years, some scientists now see it as the “third pillar” of health, alongside a good diet and taking exercise.
Researchers believe too many people neglect their rest out of a misplaced pride at being too busy to sleep.
In a study, they monitored the sleep patterns of 164 adults in a hotel for seven days.
The volunteers were then given nose drops containing the common cold virus so scientists could see who became ill. The lightest sleepers – those who got less than five hours of sleep – were four and a half times as likely to get the sniffles.
Factors including the participants’ social background, their cigarette and alcohol use and temperament were also taken into account – but sleep was found to have the greatest effect.
Lead researcher Aric Prather, assistant professor of psychiatry at the University of California San Francisco, said the findings emphasised the importance of sleep.
He added: “It goes beyond feeling groggy or irritable. Not getting enough sleep affects your physical health. Sleep goes beyond all the other factors that were measured. 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 and was an overwhelmingly strong predictor for susceptibility to the cold virus. In our busy culture, there’s still a fair amount of pride about not having to sleep and getting a lot of work done.
“We need more studies like this to begin to drive home that sleep is a critical piece to our well-being.” The research may be a better test of the risks of chronic sleep deprivation than experiments in which scientists deprive volunteers of sleep, because it is based on people’s normal sleep patterns.
The dangers of insufficient sleep are increasingly likely to be taken seriously. Experts at the US Centres for Disease Control and Prevention claim insufficient sleep is a public health epidemic linked to car crashes, industrial disasters and medical errors.
The NHS recommends eight hours’ sleep for adults. But a 2013 survey by the National Sleep Foundation found 18 percent of Britons get less than six hours sleep on work days, while 12 percent sleep for less than six hours on their days off. Such sleep deprivation can affect health in different ways.
Hormones that keep us awake such as cortisol and adrenaline have the effect of suppressing the immune system. But during sleep, hormones that promote the growth of infection-fighting white blood cells circulate in our bodies.
Sleep also improves the “memory” of the immune system. When given a vaccine against a specific infection, getting more sleep has been found to increase the antibodies produced by the body in response.
Other health benefits include the release of hormones that initiate tissue repair to organs and muscles. A lack of slumber is also linked to obesity and diabetes, possibly because getting more sleep helps stop us putting on weight as the appetite-suppressing hormones ghrelin and leptin are released when we snooze.
Getting enough sleep aids recall as it is at night that our memories are consolidated. A good night’s sleep also helps reduce blood pressure and the risk of depression.
Daily Mail