14 DAY TRIAL // Researchers have always believed that consuming coffee several hours before going to bed reduces the quantity and quality of sleep for consumers. Their hypothesis was finally confirmed in a new study, which demonstrated that people should not consume caffeine less than 6 hours before going to bed.
Doctors and physicians have always recommended to their patients that they do not consume coffee or other caffeine products in the late afternoon and during the evenings. The research, led by scientists at the Detroit Medical Center (DMC), finally provides objective evidences to support this advice.
The investigations team was coordinated by experts M. Safwan Badr, MD, and Christopher Drake, PhD, who was also the lead author of a new paper detailing the findings. The work appears in a recent issue of the American Academy of Sleep Medicine's (AASM) Journal of Clinical Sleep Medicine.
For the research, the team asked participants to consume 400 milligrams of caffeine – the equivalent of 2 or 3 cups of coffee – either before going to bed, or 2 to 6 hours before. Results showed that consuming this chemical even 6 hours before bedtime translated into a 1-hour sleep loss, on average.
Interestingly, patients in the study reported subjectively that they felt no loss of sleep, and that they were unaware they were piling up what researchers call sleep debts, PsychCentral reports.
“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,” Drake explains. He adds that many people do not relate actions they take in the afternoons to their inability to sleep at night.
“People tend to be less likely to detect the disruptive effects of caffeine on sleep when taken in the afternoon,” Drake argues. The new study was conducted on 12 participants, whose sleep patterns were measured with both a subjective sleep diary and an objective medical recorder.
One of the most important conclusions in this research, scientists say, is that people should avoid consuming coffee after 5 pm in the afternoon. Doing so could help ensure that they always get a good night's sleep, barring other problems that may keep them awake.