Kenneth Wright, director of the Sleep and Chronobiology Laboratory at the University of Colorado Boulder, is the corresponding author on a recent study investigating caffeine’s effect on circadian rhythms. (A circadian rhythm consists of changes within an individual that follow a 24-hour pattern. The term “circadian” derives from two Latin terms: “circa” meaning “about” or “approximately” and “dies” meaning “day.”)
A team of nine researchers studied five people “under highly controlled conditions” for a little more than a month and a half. Participants experienced a series of conditions the team hypothesized could affect sleep cycles, including a dose of caffeine equivalent to a double espresso.
Using laboratory techniques, the scientists attempted to discover how caffeine might be effecting chronobiology at the cellular and intracellular level. They found daily consumption equivalent to drinking a double espresso three hours before a regular bedtime shifted melatonin patterns by about 40 minutes.
The authors suggest “…caffeine may be useful for resetting the circadian clock to treat jet lag induced by international time zone travel.”
Learn more: http://stm.sciencemag.org/content/7/305/305ra146