Coffee, late-night shifts can affect sleep

Coffee’s main by-product caffeine meddles with sleep. So, night-shift workers should keep their distance from coffee machines if they wish to have quality sleep, researchers have said.

Night-shift workers should keep their distance from coffee machines if they wish to have quality sleep, researchers have said.

Julie Carrier, a Université de Montréal psychology professor and a researcher at the affiliated Hôpital du Sacré-Cœur Sleep Disorders Centre, discovered that coffee’s main by-product caffeine meddles with sleep. The lead investigator of the study further found that the side-effect grew worse with age.

Carrier said, "Caffeine is the most widely used stimulant to counteract sleepiness, yet it has detrimental effects on the sleep of night-shift workers who must slumber during the day, just as their biological clock sends a strong wake-up signal. The older you get, the more affected your sleep will be by coffee."

She added, "We all know someone who claims to sleep like a baby after drinking an espresso. Although they may not notice it, their sleep will not be as deep and will likely be more perturbed.”

Carrier advised those over 40 to particularly cut down on their coffee intake, explaining the combined influence of age and caffeine that made the sleep of middle-aged subjects vulnerable to the circadian waking signal.