Coffee delays your body clock

Posted on Tue, 29 Sep 15

Researchers have shown that a daily dose of coffee delays your body clock, which helps explain why it can disturb sleep.

Coffee is well known to keep you awake, but very little research has explored the effects of coffee on your body clock (circadian rhythm). In a series of experiments on cell cultures and in people, it has been discovered that coffee significantly delays circadian rhythm of the sleep hormone melatonin.

In the study it was found that a double espresso 3 hours before regular bedtime induced a 40-min phase delay of the circadian melatonin rhythm. Furthermore, the scientists cultured cells with receptors known to be sensitive to caffeine (adenosine receptors) and demonstrated that caffeine disrupts intracellular clock genes and cellular timekeeping.

“Not only do these results reinforce the common advice to avoid caffeine in the evening,” commented the journal Editor, “but they also raise the intriguing possibility that caffeine may be useful for resetting the circadian clock to treat jet lag induced by international time zone travel.”

Reference:

Burke TM, et al. Effects of caffeine on the human circadian clock in vivo and in vitro. Sci Transl Med. 2015 Sep 16;7(305):305ra146.