Research says drinking espresso before going to bed will delay the body's biological clock: it's hard to sleep at night.

Chinanews.com, Sept. 18-according to foreign media reports on the 18th, researchers in the United States have found that drinking two espressos three hours before going to bed will disrupt the body clock and make it difficult to sleep at night and get up in the morning.

According to a report published in the journal Science Translational Medicine, the findings not only show that it is really inappropriate for people to drink coffee at night, but also help travelers adjust their coffee drinking time and help them cope with jet lag.

Researchers at the University of Colorado recruited two men and three women to participate in the trial. During the 49-day study, they took a placebo or a caffeine pill three hours before bed, which contained the same amount of caffeine as two espresso.

The researchers regularly tested the levels of melatonin (melatonin) in the saliva of the participants, an important regulator of the body clock. The results showed that compared with taking a placebo in low light, taking a caffeine pill in low light delayed the body clock by about 40 minutes, while being exposed to sleep-disrupting bright light for three hours delayed the body clock by 85 minutes. If the strong light plus caffeine tablets, the body clock will be delayed by 105 minutes.

This is the first study to show that caffeine has an effect on the body clock. Kenneth Wright, a professor at the university who led the study, said in a statement that the results also have important implications for the development of treatments for circadian rhythm disorders.