Drinking coffee six hours before bedtime may lead to insomnia.

Coffee drinkers should be careful. Even if they drink coffee at four or five o'clock in the afternoon, their sleep at night may still be disturbed. Even drinking coffee six hours before bed can affect sleep and increase the risk of insomnia, a new study in the United States has found.

Christopher Drucker, lead author of the study, said that drinking a large cup of coffee in the evening may interfere with sleep, which is similar to drinking coffee before going to bed. However, when drinking coffee in the evening, most people are not aware that this may affect their sleep at night. The results show that the effect of caffeine lasts for a long time, even drinking coffee six hours before going to bed can be affected. The results have been published in the Journal of Clinical Sleep Medicine.

A total of 12 healthy adults participated in the study. These people usually slept normally, and the researchers asked them to go to bed and sleep at the usual time. But the researchers gave these people three pills a day and asked them not to take ​​ six hours before bed, three hours before sleep and before going to bed for four days. One of the three pills contains 400 milligrams of caffeine, which is equivalent to two to three cups of coffee, and the other two pills contain a placebo without caffeine. Another four days to do another experiment, this time all the pills are placebo.

The researchers found that as long as these people take caffeinated pills, whenever they take them, they can affect their sleep. Even if you take it six hours before you go to bed. After taking caffeine pills, sleep time is reduced by more than an hour at night.

The team advises people to avoid drinking coffee after 5 p.m., if they want a good night's sleep. Steve Van Silver, director of the Sleep Medical Center of Mount Sinai Hospital in the United States, said in an interview with foreign media that many people do not know exactly how much caffeine they consume in a day. Caffeine not only affects sleep, but also interferes with sleep quality, sometimes as long as 12 hours. If you usually don't sleep well and are not easy to sleep, you should try to drink less coffee, especially in the afternoon, and avoid drinking coffee. It is recommended that you drink coffee at intervals of more than eight hours, which will be better for sleep.