Now you’ll know the reason why a cup of coffee can keep you from feeling drowsy. Research shows that some 200mg of caffeine – the amount found in some High Street coffees – slows down the body clock in a such way that the brain is a whole time zone behind.
In fact, British and US research also suggest that the beverage could be an effective option for treating jet lag. For the study, men and women participants lived in a windowless and clockless laboratory for seven weeks. While on some nights, they were given a caffeine pill before going to bed, other nights they took a dummy drug.
The saliva of the participants was tested regularly for levels of melatonin, a hormone is made as night draws in, which makes us feel sleepy. The caffeine pill and a dimly-lit bedroom delayed the rise in melatonin levels by 40 minutes on average, which is the equivalent of crossing one time zone when flying west.
It was found that the overall effect on people who had the caffeine pill was the same as being exposed to bright light for three hours when trying to get to sleep, according to a report published in the Daily Mail.
