Caffeine resets body’s clock
After-dinner coffee induces 40-minute time delay
Post-dinner coffee can lead to sleepless nights — not a surprise. A new study helps reveal why. Caffeine before bed distorts the master clock that tells the body what time it is. An evening dose of less caffeine than 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, orchestrating the circadian rhythms that control everything from sleep to appetite to hormone levels (SN: 4/10/10, p. 22, SN: 7/25/15, p. 14). 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.