Can Caffeine Actually Cause Insomnia?

by Martin Reed Patient Advocate

We all know of the stimulating properties of caffeine. (Some of us can't survive without it) That being said, experts often suggest reducing or eliminating caffeine consumption as a way to improve sleep and alleviate insomnia symptoms.

But is that good advice? Does caffeine actually cause insomnia? How does caffeine affect sleep?

A 2016 study published in the journal Nutrition set out to determine whether caffeine consumption is associated with insomnia symptoms. Some of its findings were surprising.

The study reviewed data from the 2007-2008 National Health and Nutritional Examination Survey (NHANES), which evaluates health and nutritional characteristics of the U.S. population.

The review used data from 4,730 adults. The average age of the study population was 46 and 51.6 percent were women.

Caffeine consumption was categorized into the following groups:

  • None

  • Light (120 mg per day or less)

  • Moderate-heavy (More than 120 mg per day)

Sleep quality was measured by assessing:

  • Difficulty falling asleep

  • Difficulty staying asleep

  • Non-restorative sleep

  • Daytime sleepiness

  • Sleep duration

How caffeine affects sleep

Before adjustments, researchers found that greater caffeine use was associated with:

  • Difficulty falling asleep

  • Difficulty staying asleep

  • Non-restorative sleep

However, after adjusting for covariates such as age, anxiety, ethnicity, education, and general health, these associations were no longer seen — but a link did begin to emerge between greater caffeine use and difficulty staying asleep.

Interestingly, researchers did not find a link between the level of caffeine consumption and sleep quality. In other words, those who consumed the highest levels of caffeine were not found to have a significant difference in their sleep quality compared to those who consumed the least.

How ethnicity and anxiety affects sleep and caffeine consumption

The link between greater caffeine use and poor sleep quality — in particular, difficulty staying asleep and non-restorative sleep — was especially pronounced when models included race/ethnicity and anxiety covariates.

Those who identified as white and those with symptoms of anxiety consumed more caffeine — and this appeared to have a negative impact on their sleep.

As the authors of the study pointed out, this suggests that race/ethnicity and anxiety symptoms have a strong influence on the relationship between caffeine use and insomnia symptoms.

More studies are needed to examine this potential link.

Is caffeine consumption linked to insomnia symptoms?

The short answer is yes.

Researchers found that daily caffeine use was linked to insomnia symptoms and that underlying anxiety and differences in race/ethnicity may play a role.

Those who slept for less than six hours per night consumed more caffeine, and were more likely to experience non-restorative sleep.

Can you drink coffee and still get a good night's sleep?

You don't have to eliminate coffee and caffeine entirely — but it's best to limit caffeine consumption to the morning hours.

In fact, one study found that drinking just one cup of coffee containing 90 mg of caffeine after dinner can lead to poorer sleep quality, delayed sleep onset and more nighttime awakenings.

Caffeine can take a long time for the body to process and its stimulating effects can last for many hours after consumption. Being aware of these facts can help you continue to enjoy coffee and other caffeinated products while minimizing the negative effect on your sleep.

Martin is the creator of Insomnia Land’s free sleep training for insomnia. His online course uses CBT techniques to teach participants how to sleep__ without relying on sleeping pills. More than 4,000 insomniacs have completed his course and 97 percent of graduates say they would recommend it to a friend.

Martin Reed
Meet Our Writer
Martin Reed

Martin is the creator of Insomnia Coach, an eight-week course that combines online sleep education with individual sleep coaching. His course helps clients improve their sleep so they can enjoy a better life with more energy and start each day feeling happy, healthy, rested, and refreshed. Martin also runs a free sleep training course that has helped over 5,000 insomniacs. He holds a master’s degree in health and wellness education and studied clinical sleep health at the University of Delaware.