March 4, 2012 by David K. Sutton
Have Another Cup Of Coffee: Caffeine Affects Night Owls Less
Scientific American reports a new study about caffeine and sleep shows that morning people are more likely to experience sleep disruption from caffeine intake during the day.
In the study, “morning people” who consumed caffeine during the day appeared more likely than late risers to awaken in the middle of their nighttime sleep.
The researchers said this is the first study to link caffeine intake with “chronotype,” the categorizing of people by the time of day they are most alert and active.
Being a night owl myself, maybe this explains why my sleep isn’t affected by coffee consumption, even if consumed in the evening. I rarely have a problem getting to sleep and staying asleep, and if I do wake up, I typically fall right back to sleep. Of course caffeine can have other effects beyond the scope of this study.
The study asked 50 college students to keep track of caffeine intake along with waking times for one week. They wore devices that monitored movements to record when they awoke during the night.
The next step is to see whether this effect applies to people other than college students, Zeitzer said.
Researcher Jamie Zeitzer said, “Some people’s bodies clear caffeine within a few hours, but lunchtime coffee may still be in the system of other people even late at night.” This fact makes it difficult to decide at what time during a day a person should stop consuming caffeine to ensure a good night’s sleep.