What Coffee Can't Do
If you're like millions of Americans, it's more likely than not that your day begins with a cup of Joe. According to the National Coffee Association, 7 in 10 Americans consume coffee every week, while 62% consume coffee every day, and the average coffee drinker knocks back three cups of the stuff daily. We are a nation of coffee drinkers. In fact, U.S. coffee consumption has been on the rise, with a 5% increase since 2015.
Perhaps not coincidentally, we are also a nation of sleep-deprived people. According to the CDC, while adults need 7 hours or more nightly sleep in order to receive proper rest, roughly 35% of U.S. adults average less than that. We're not talking about people occasionally missing a night of shut-eye here or there, but those who are habitually, regularly sleep-deprived.
While it's true some people drink coffee or other caffeinated beverages for the taste, it's also true that many of us are running on a sleep debt, and trusting java to make up the difference. However, what does the science say about bridging a sleepless night with a serving of coffee?
Researchers at Michigan State University's Sleep Lab, led by psychology associate professor Kimberly Fenn, recently set out to see just how well caffeine does at counteracting the impact of sleep deprivation on the brain. More than 275 volunteers were recruited, and asked to complete both a simple attention task and a more complicated "placekeeping" task after a night with no sleep. (The placekeeping task required the participant to complete a series of steps in a specific order, without skipping or repeating steps.)
“We found that sleep deprivation impaired performance on both types of tasks and that having caffeine helped people successfully achieve the easier task," said Fenn. "However, it had little effect on performance on the placekeeping task for most participants."
Unfortunately, our daily routines are full of placekeeping tasks. Consider the steps required to change lanes on the highway, or, depending on your job, to draft a good email or perform open-heart surgery. “Caffeine may improve the ability to stay awake and attend to a task, but it doesn’t do much to prevent the sort of procedural errors that can cause things like medical mistakes and car accidents," Fenn said.
A morning latte may help you feel more alert, but cognitively speaking, it is certainly no substitute for a night of good sleep. In fact, that hit of caffeine may give you false confidence when it comes to your level of alertness; you might feel awake but still find yourself making crucial errors on higher level tasks. Fenn notes that this is part of what makes sleep deprivation just so dangerous.
If you're one of those 62% of Americans whose wake-up routine includes a cup of caffeinated liquid, you don't necessarily need to ditch it, but remember: that little rush you get does not necessarily equal a refreshed and renewed brain, especially if you clocked insufficient sleep the night before.
“If we had found that caffeine significantly reduced procedural errors under conditions of sleep deprivation, this would have broad implications for individuals who must perform high stakes procedures with insufficient sleep, like surgeons, pilots and police officers,” said Fenn. “Instead, our findings underscore the importance of prioritizing sleep.”