This blog post will discuss the benefits of sleep and the costs to health and productivity of insufficient sleep. The second part, coming later this month, will offer suggestions for getting more and better sleep.
How many hours of sleep do you get per night? Most adults require seven or eight hours. Thirty percent of employed Americans now report getting six hours of sleep or less per night, which can lead to job burnout, and nearly 70 percent describe their sleep as insufficient. According to the CDC, 28% of adults reported getting an average of 6 hours of sleep per day or less. One study reported that 71% of Americans sleep with a cell phone next to their bed. The blue light emitted acts as a stimulant. We have too many devices in our homes, often in our bedrooms, that emit beeps and other sounds, that glow or emit some type of light, and that vibrate, all of which can disturb sleep.
According to a poll by the National Sleep Foundation, nearly a third of adults complain that daytime sleepiness interferes with their lives. Sleep is vital for keeping us mentally sharp and alert. Neurocognitive functions, like short-term memory and high-level mental tasks that require paying attention to several things at once, are particularly vulnerable to sleep loss. Research shows that any degree of sleepiness will impair performance and mood, so getting too little sleep can undermine productivity, creativity, and effectiveness, and can lead to serious health consequences down the road. Sleep deficits are cumulative; if you lose a half night of sleep, your body carries the debt forward into the next day, and the next.
The total annual cost of sleep deprivation to the US economy has been estimated to be more than $63 billion in the form of absenteeism and presenteeism (when employees are present at work physically but not really mentally focused). “Americans are not missing work because of insomnia,” said Harvard Medical School professor Ronald C. Kessler. “They are still going to their jobs, but they’re accomplishing less because they’re tired. In an information-based economy, it’s difficult to find a condition that has a greater effect on productivity.”
The media is replete with articles and books about sleep, mainly because research is showing us how important sufficient, good-quality sleep is for brain health, and for physical health as well. Arianna Huffington, in her recent book, The Sleep Revolution, addresses the trend to sacrifice sleep in order to complete tasks on our to-do list. She cites findings from science that show the association between sleep deprivation and increased risk for diabetes, heart attack, stroke, cancer, obesity, and Alzheimer’s disease. P. Murali Doraiswamy has reported that sleeping less than seven or eight hours a night is linked to cognitive decline, memory loss, and possibly even Alzheimer’s disease. The last hour of sleep may be the most important, mainly because it is usually the last hour of REM (Rapid Eye Movement) sleep. Separate studies done by James B. Maas and Robert Stickgold revealed that getting less than six and a half to seven hours of sleep can negatively affect learning, problem-solving, and memory.
Sleep deprivation also impairs mood, possibly because it keeps the brain from replenishing neurotransmitters such as dopamine. William C. Dement, in The Promise of Sleep, wrote, “When we don’t have enough sleep, … we are more easily frustrated, less happy, short-tempered, less vital.” Our metabolic system is also partly regulated by sleep, so sleep deprivation can affect appetite and the body’s use of glucose, possibly leading to insulin resistance. A 2015 Swedish study found that losing even one night of sleep can lead to glucose intolerance and cause genes that control the biological clocks in your cells to fall out of sync, harming the body’s metabolic processes. Sleep is also essential for immunity, and research shows a relationship between insufficient or irregular sleep and higher risk of colon cancer, breast cancer, heart disease, and type 2 diabetes.
Duke Medical Center researchers found that women tend to need more sleep than men. For women, poor sleep is strongly associated with high levels of psychological distress and greater feelings of hostility, depression and anger than in men who experienced the same degree of sleep disruption.
James Maas, author of Sleep for Success! Everything You Must Know about Sleep but Are Too Tired to Ask, writes, “As a predictor of longevity, your behavior around sleep is more accurate than your diet and exercise habits.” I hope this article has convinced you of the importance of sleep. In my next blog I will share tips for getting better sleep.