The effects of caffeine are long lasting! This substance acts long enough to disrupt the sleep of people who have consumed it in the afternoon.
We suspected that drinking coffee late in the evening prevents sleep, researchers at Wayne State University in Detroit (United States) wanted to scientifically understand the effects of caffeine taken during the day on sleep.
For four days, 12 healthy volunteers with no sleep problems received 3 capsules that they were to take 6 hours before, 3 hours before and at bedtime. During the first 3 days, the volunteers absorbed one tablet comprising 400 mg of caffeine (i.e. 2 to 3 cups of coffee) and two placebos (one inactive tablet). During the entire test, they did not know what type of pill they were taking.
To establish the quality of a “caffeine-free” sleep, and to be able to make comparisons, only placebos were given to the “guinea pigs” on the fourth day.
If their sleep was analyzed “objectively” by monitors during these four nights, the volunteers had to supplement this scientific data with their perceptions.
Caffeine prevents sleep even when taken 6 hours before bedtime
The results of this study confirm that drinking coffee before bed prevents sleep but also reveals that consuming caffeine 6 hours or 3 hours before going to bed disrupts sleep and even reduces the time it takes to fall asleep by an hour. .
As surprising as it may sound, the study participants didn’t realize that they had lost that hour of sleep.
Professor Christopher Drake, associate professor of psychiatry and behavioral neuroscience, director of the study concludes that “to preserve sleep, it is recommended not to drink coffee after 5 p.m. and watch out for hidden sources of caffeine in the body. tea and energy drinks “.
The findings of this study were published in the Journal of Clinical Sleep Medicine.
