Although it is a known fact that coffee will help people stay up at night, the drink actually has deeper effects particularly on a person’s body clock.
A study published in Science Translation Medicine presented that caffeine can actually slow down the internal clock of the body. According to experts, people’s own actions had a major effect their body clock and sleep.
"If you're tired and having a coffee at night to stay awake, then that is a bad idea, you'll find it harder to go to sleep and get enough sleep,” Dr. John O’Neill, one of the researchers from the Laboratory of Molecular Biology of the Medical Research Council, told BBC News.
Part of the study involved growing cells in a dish and then exposing these to caffeine to determine their ability to keep time may have changed. The results showed that caffeine changed the chemical clocks that function in every cell of the human body. Drinking a double espresso three hours before sleeping can delay the production of melatonin, the sleep hormone, by about 40 minutes, which would make it more difficult for people to sleep.
Another part of the study involved five participants being exposed to bright lights. Those who were exposed to bright lights had their circadian rhythms set back by 85 minutes.
Based on conducted experiment, the scientists discovered that taking a dose of caffeine at night would slow the body clock by 40 minutes. The effect was about half of what three hours of bright light during bedtime would cause.
Professor Kenneth Wright of the University of Colorado, Boulder, said that it was the first study to show that caffeine, the most widely used psychoactive drug on Earth, had an effect on the human body clock, based on a report by Yahoo.
Dr. O’Neill said that the results can help treat a number of sleep disorders and individuals who tend to wake up very early during the day. He added that taking caffeine at the right time can actually help people recover from jet lag faster.
Professor Derk-Jan Dijk from the University of Surrey said that people have different sensitivities to caffeine, so the best time to avoid coffee may differ. The findings, however, show that people can modify their body clocks by adjusting factors such as exposure to artificial light and consuming caffeine at night, based on the same BBC report.