Caffeine Can Only Help So Much If You Don’t Get Enough Sleep

• Experts say caffeine can help you stay awake if you’re sleep deprived, but it probably won’t improve your performance on tasks.
• They say caffeine is not a substitute for a good night’s sleep, which helps repair tissue and cleanse the brain.
• They note that too much caffeine can also disrupt sleep patterns.

Caffeine may keep you alert enough to take on tasks if you’re short on sleep, but you probably won’t do them particularly well.

In a study published in the Journal of Experimental Psychology: Learning, Memory, & Cognition, a group of participants subjected to a night of sleep deprivation was asked to complete a simple memory test as well as a more complex “place-keeping” test, which required the completion of a series of tasks in a specific order without skipping or repeating any steps.

The researchers noted that caffeine did help in some instances.

“We found that sleep deprivation impaired performance on both types of tasks and that having caffeine helped people successfully achieve the easier task,” said Kimberly Fenn, PhD, an associate professor in the department of psychology at Michigan State University, in a press release. “However, it had little effect on performance on the place-keeping task for most participants.”

Fenn told Healthline that there is a simple takeaway from the study.

“Caffeine may be able to help you stay awake and pay attention to a task, but it does not help to prevent errors,” she said. “We are interested in procedural errors because they can be quite dangerous. For example, many medical professionals, such as surgeons, need to work long hours throughout the night.”

She also has some guideposts on what kind of tasks should be avoided if you’re short on sleep.

“I think the best way to conceptualize this is that one would not want to attempt any task that has consequences while sleep deprived,” said Fenn. “So I would caution against doing anything like driving or operating heavy machinery or performing any task in which an error could be significant. A good rule to follow is that you should not attempt any task while sleep deprived that you would not (or should not) attempt while intoxicated, irrespective of caffeine.”