A new study has revealed why drinking coffee after dinner can lead to a sleepless night.
Caffeine before bed distorts the master clock that tells the body what time it is, and it was found that an evening dose of less caffeine than whjat is in a Starbucks tall medium roast delayed people’s clocks by about 40 minutes, scientists report September 16 in Science Translational Medicine.
Bodily clocks tick throughout the body and caffeine taps directly into the master clock that syncs these far-flung timekeepers, Kenneth Wright of the University of Colorado Boulder and colleagues found. “This suggests that caffeine has a larger impact on us than we may have realized, from the circadian perspective,” he says.
The results have implications for the huge number of people who consume one of the world’s most popular stimulants, says pharmacologist and sleep researcher Hans Peter Landolt of the University of Zurich. Figuring out the details of how caffeine influences the body’s clocks might lead to better ways to prevent or treat sleep disorders, he says.
While the study is a good first step, there’s still much more to learn, says Landolt. Factors like age, genetics and culture can all influence how people respond to caffeine. More studies are needed to untangle how the stimulant influences people’s daily lives.