A recent study found that consuming even one cup of coffee after lunch could result in losing as much as one hour of sleep at night.
Your coffee addiction could be depriving you of much-needed sleep at night, especially if you down a cup in the late afternoon or early evening. A new study recently published in the Journal of Clinical Sleep Medicine found that people who consume even just one cup of coffee after lunch could be losing as much as one hour of sleep every night, leaving them groggy and sleep-deprived the following day.
For the research, Dr. Christopher Drake, Ph.D., an investigator at the Henry Ford Sleep Disorders and Research Center and associate professor of psychiatry and behavioral neurosciences at Wayne State University in Detroit, Michigan, tested the effects of caffeine on 12 individuals deemed to have otherwise normal and healthy sleeping patterns. Each participant was given three caffeine pills daily for four days, which were to be taken at scheduled intervals of one pill six hours before bedtime, another three hours before bedtime, and the last one right before they went to sleep.
According to the study, two of the pills were placebos, meaning they contained no caffeine, while the third contained 400 milligrams (mg) of caffeine, or the rough equivalent of two-to-three cups of coffee. On one of the four days, all three of the pills were placebos, but the participants did not know which day this was, nor were they made privy to which pills contained caffeine on the other days. And during the study period, all participants were told to keep a personal sleep diary and were also monitored with special in-home sleeping monitors.
At the end of the trial, researchers compiled the data and found that taking caffeine in the afternoon can disrupt normal sleeping patterns, as its effects can last up to six hours after consumption. Even among those who typically sleep just fine even when drinking coffee in the morning, consuming caffeine in the afternoon was discovered to have detrimental effects on their sleep, which they may not even notice, other than being generally more tired.
“Drinking a big cup of coffee on the way home from work can lead to negative effects on sleep just as if someone were to consume caffeine closer to bedtime,” stated Dr. Drake, who is also on the board of directors of the Sleep Research Society, in a press release following the study’s publishing. “People tend to be less likely to detect the disruptive effects of caffeine on sleep when taken in the afternoon.”
Some people’s bodies take much longer to process caffeine than others
The findings align with previous research on caffeine, including a 2012 study involving college students which found that caffeine can linger in people’s systems for many hours after consumption. While some people might be able to clear it out of their systems in just a few hours, many others tend to feel its effects well into the evening, which ends up interfering with the normal sleep cycles of their bodies.
“Sleep specialists have always suspected that caffeine can disrupt sleep long after it is consumed,” says Dr. M. Safwan Badr, M.D., president of the American Academy of Sleep Medicine. “This study provides objective evidence supporting the general recommendation that avoiding caffeine in the late afternoon and at night is beneficial for sleep.”