Can't you sleep if you drink coffee? Drinking coffee before going to bed may change the biological clock

You and I both know that drinking coffee or other energy drinks at night is stupid-unless we have to use them to cheer us up. Now, however, we have more evidence of how unhealthy and unscientific it is to do these things-researchers have found for the first time in a new study that caffeine intake at night delays the body's body clock.

Eating a cup of espresso (or other drink with the same amount of caffeine) three hours before bed can delay your biological clock by 40 minutes, the new study found. The lead author of the study, John O'Neill of the MRC Molecular Biology Laboratory in the UK, said in a statement: "people have known for a long time that caffeine has an effect on sleep, waking and exciting. But the exact effect of caffeine on the biological clock is still unknown. By understanding the effects of caffeinated drinks on the biological clock of individual cells in our bodies, we have a deeper understanding of how caffeine affects our body clock-of course, the results are mixed. "

Circadian rhythm is a 24-hour biological process that mediates our wakefulness or sleep. This is true not only for humans, but also for other animals and plants, which are extremely sensitive to changes in the natural environment, such as light, and respond positively.

To determine the effect of caffeine on our circadian rhythm, the researchers recruited volunteers to participate in a 49-day experiment. The volunteers were divided into four groups to sleep under different conditions: the first group was given a placebo pill in a low light environment; the second group was given a caffeine pill in a low light environment (containing 200 milligrams of caffeine. The volunteers' weight was adjusted accordingly); the third group was given a placebo pill in a bright light environment; and the fourth group was given a caffeine pill in a strong light environment. Saliva samples from the volunteers were also sent for analysis to help researchers track changes in levels of melatonin, a hormone secreted by the pineal gland that regulates circadian rhythms.

In the experiment, the researchers found that volunteers who took caffeine pills delayed their circadian rhythm by 40 minutes in low light compared to those who took a placebo. If it is in a strong light environment, the circadian rhythm will be delayed for up to 105 minutes.

"the findings may have important implications for patients with sleep disorders and may even help us overcome jet lag," O'Neill said. Our findings also explain more fully why people who have had coffee at night have trouble falling asleep. " Indeed, jet lag is always unpleasant, and this study may provide us with a quick and convenient way to reverse jet lag: if you are traveling west, you can consider taking some caffeine to help your body adapt to local time. If you travel east, you should avoid caffeine.