Does coffee really disturb our sleep?

Have coffee before going to sleep?

For a long time it was said that people should not drink coffee before going to bed if they do not want to have trouble falling asleep. But researchers have now found that it is not caffeine that disturbs our sleep, unlike alcohol and nicotine.

A recent Florida Atlantic University study found that people taking caffeine before bed didn't have any negative effects. However, nicotine and alcohol have a negative impact on sleep. The results of the study were published in the English language journal "Sleep".

Do nicotine and alcohol affect our sleep?

If you're worried about your night's sleep, it's better to have an espresso before going to sleep than an alcoholic nightcap. The researchers found that alcohol consumption disrupts sleep, while caffeine does not. The effects of smoking were even stronger. Nicotine has been linked to insomnia, especially when smoking in the evening.

Consuming coffee definitely didn't affect sleep

The study found no association between coffee consumption and insomnia. Even after excluding other factors that can affect our sleep, such as age, gender, obesity, work or school the next day, depression, anxiety, and stress, caffeine had little effect on sleep.

Structure of the study

A total of 785 people took part in the study for a period of 14 years. None of the participants suffered from clinical sleep disorders. The study is one of the largest longitudinal studies on how alcohol, caffeine and smoking affect sleep at night. All participants received a wristband sensor to monitor their sleep. They also kept a so-called sleep diary. It noted how they slept, how they felt, and what food they consumed each night. In addition, the participants indicated whether and how much they had drunk and smoked. Self-reports are often flawed, but researchers were confident that their published results were accurate.

Smokers sleep worse

People particularly often had trouble sleeping after drinking alcohol. Participants most often suffered from sleep problems if they consumed alcohol relatively soon before going to bed. When people smoked or used e-cigarettes to vaporize nicotine, they slept an average of 43 minutes less per night than non-smokers, the researchers report. (as)

Author and source information

This text corresponds to the requirements of the medical literature, medical guidelines and current studies and has been checked by medical doctors.


  • Christine E Spadola, Na Guo, Dayna A Johnson, Tamar Sofer, Suzanne M Bertisch et al .: Evening intake of alcohol, caffeine, and nicotine: night-to-night associations with sleep duration and continuity among African Americans in the Jackson Heart Sleep Study, in sleep (query: 07.08.2019), sleep

Video: Does caffeine affect your sleep? (January 2022).