The recent study has shown that intake of coffee during night-shifts negatively affects quality of sleep during day, and this phenomenon goes on worsening with the age.

Caffeine can interfere with sleep.

Research team led by Julie Carrier, a Universite de Montreal psychology professor, analyzed data collected from twenty-four men and women. The study subjects were divided in two groups.

First comprised of study subjects aged 20 to 30, while the second group had study subjects aged 45 to 60. The study subjects had spent two sleepless nights before being allowed to sleep.

Both the groups had taken either 200 milligrams of caffeine or a lactose-based placebo three hours before sleeping.

It was found that the study subjects who had consumed caffeine pills had slept about 50 percent less than usual. Caffeine also negatively affected sleep efficiency, sleep duration, slow-wave sleep (SWS) and REM sleep.

Julie 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 as their biological clock sends a strong wake-up signal. The older you get, the more affected your sleep will be by coffee.”