If Napoleon were right, most people would be idiots. After all, the French general is supposed to have said: “A man sleeps four hours, a woman five, an idiot six.” Whatever. The retort to that could be “better to be an idiot than run the risk of getting sick from too little sleep”. This risk does exist, as researchers from the University of Paris, among others, have shown. The team of scientists led by Séverine Sabia used data from nearly 8,000 women and men from the United Kingdom over a period of 25 years to investigate the correlation between sleep duration and chronic diseases such as diabetes, heart disease, and cancer. Published in October 2022 in the journal PLOS Medicine, the results show that permanently short sleep durations of less than five hours, compared to seven and eight hours of sleep, are associated with a 20 percent increased risk of chronic disease and subsequent multiple illnesses or multimorbidity.
High risk of error and immense costs
There is a reason why the American Academy of Sleep Medicine and the Sleep Research Society recommend that adults should sleep at least seven hours per night. Healthy people have a regular sequence of half-sleep, deep sleep, and dream sleep. They form the basis of the so-called sleep architecture. Ideally, five cycles of about 90 minutes each should be completed per night. When getting up, it is advisable to get going quickly. Five minutes of snoozing should be enough. Then you can start your day well rested.
Lack of sleep affects both physical and mental health. “In the workplace, excessive sleepiness significantly increases the likelihood of work-related accidents, which can lead to injury and, in the worst case, can be fatal,” says Grace Thai, Principal Consultant at DEKRA North America. Similarly, she says, sleep deprivation impacts other aspects of job performance, including productivity, task management, and goal achievement. In fact, numerous studies show that people who sleep less are more likely to get sick, have more absences from work, and become more prone to making mistakes. This often affects shift workers.
“The level of fatigue can increase or decrease depending on the duration and quality of sleep, rest, and stress-relieving activities,” Grace Thai adds, citing a study by the Liberty Mutual Research Institute for Safety. According to the study, people are twice as likely to make mistakes after 5.5 to 6.5 hours of sleep per night as a person with more than 6.5 hours of sleep. With less than 5.5 hours of sleep, the risk of error is almost five times higher.
In addition, fatigue at work causes immense annual costs due to lost productivity and absenteeism, as the think tank Rand Europe calculated a few years ago in its study for five OECD countries. At 411 billion dollars, the US economy suffers the greatest loss. It is followed by Japan with 138 billion dollars, Germany with 60 billion dollars, the United Kingdom with 50 billion dollars, and Canada with 21.4 billion dollars. These numbers could be adjusted downward with comparative ease. For example, if all Americans who sleep less than six hours were to slumber for at least one hour more, the economy could save 226.4 billion dollars. In Germany, this number would be 34.1 billion dollars.
Fatigue at the wheel is responsible for many accidents
In addition to occupational safety and creative energy, lack of sleep also has a massive impact on traffic safety. The “Sleep Heart Health Study”, for instance, conducted by the National Heart, Lung, and Blood Institute in Bethesda in the US state of Maryland, found that six hours of sleep per night is associated with a 33 percent increased risk of accidents, compared to seven or eight hours of sleep. Further scientific research has also shown that sleep deprivation can lead to mental impairment similar to drunkenness. In this context, 17 hours without sleep roughly corresponds to a blood alcohol content (BAC) of 0.05 percent, while 24 hours without sleep corresponds to a BAC of 0.1 percent.
Based on police and hospital reports, the National Highway Traffic Safety Administration estimates that fatige at the wheel resulted in 684 traffic fatalities in 2021 in the US – an increase of more than eight percent compared to the previous year. However, it is likely that the number of unreported cases is much higher. As the Netherlands Institute for Road Safety Research writes in its 2019 fatigue fact sheet, truck drivers, cab drivers, shift workers, and young men are particularly at risk of being involved in fatigue-related traffic accidents. “In addition to sufficient sleep and taking appropriate breaks from driving, assistance systems are of great importance in counteracting this problem,” says DEKRA accident researcher Markus Egelhaaf, referring to the General Safety Regulation adopted by the EU Commission in March 2019. The regulation makes various safety-related driver assistance systems mandatory for new motor vehicles on Europe’s roads. These include features like a warning system in the event of driver fatigue and declining attention. “This is a feature with high added value that can prevent microsleep and save lives if drivers take the warnings seriously and take a sufficient break as soon as possible,” says Markus Egelhaaf.
Behavioral changes for healthy sleep hygiene
Not many causes of sleep disorders are obvious, nor are they easy to change. These include, for example, the sleeping environment, specifically the situation in the bedroom. It should always be quiet there. Noise can severely impair sleep, which is why people who live close to airports, highways, railroad tracks, or construction sites almost always struggle with problems sleeping. Incidentally, one recent question that has been asked frequently in this context is: Does wind energy have a negative impact on health? A new medical study from Australia’s Woolcock Institute of Medical Research concludes that the so-called “quiet sound” emitted by wind turbines does not harm human health. “We were able to clearly demonstrate that infrasound generated by wind turbines does not cause dizziness or nausea, has no effect on heart health or mental health, and does not affect sleep,” said the study’s leader when presenting the findings in March 2023.
Your own behavior can also improve your night’s rest. For example, you shouldn’t eat anything too heavy late at night and should only consume alcohol in small amounts. Although alcohol makes you tired, it disrupts the important deep sleep phases and ensures that sleep is less restful overall. The same applies to caffeine and nicotine. Before going to bed, it’s best to engage in relaxation-promoting rituals such as a warm bath, breathing exercises, and yoga. People who exercise regularly also lay a solid foundation for restful sleep.