Coffee shifts our body’s internal clock by 40 minutes

According to a recent study published in Science Translation Medicine, drinking a cup coffee in the evening can help us stay awake for more reasons that what we have so far thought of. The study has shown that caffeine is much more than a mere stimulant and possesses the ability of slowing down out body’s internal clock.

Scientists conducting the study found that having a double espresso 3 hours prior to bedtime has delayed production of melatonin, the sleep hormone, by around 40 minutes. In short, drinking coffee in the evening makes nodding off a much tougher job.

A member of the study team Dr. John O’Neil, who represents the Laboratory of Molecular Biology of the Medical Research Council, Cambridge, said that drinking coffee for beating fatigue and staying awake is not a good thing to do as that will make falling asleep and getting enough sleep extremely difficult.

In O’Neil’s half of the research, cells grown on a dish got exposed to caffeine. This was done for finding out how caffeine exposure changes those cells’ ability of keeping time. It was found that the drug succeeded in altering chemical clocks of the cells.

In the meantime, a group of five at the University of Colorado, Boulder got locked inside a sleep laboratory; they were kept there for 50 days. As light exposure is the primary factor considered for controlling our body clock, during that 50 day period, the group had to spend most of their time in the extremely dim light.

Scientists kept on conducting experiments of the five people in custody. Those experiments allowed them to establish that having a cup of coffee in the evening can slow down our body clock by as much as 40 minutes. Its impact was nearly 50% of that of 3 hours of exposure to bright light during bedtime.

According to Dr. O’Neil, it’s not possible to set a specific cutoff time for drinking caffeine-based beverages in the evening. However, he informed that he himself have never had coffee after 5 pm.

Dr. O’Neil feels that findings of this study might help in treating certain sleep disorders and may be useful for individuals who have the tendency of waking up too early in the morning.