Caffeine and sleep, what’s the evidence?
Bitesize research – a brief article summary from the Sleepio team:
Clark et al. (2016). Coffee, caffeine, and sleep: a systematic review of epidemiological studies and randomized controlled trials. Sleep Medicine Reviews, published online 30 January.
Coffee and tea are part of most people’s daily routine, which makes caffeine the most widely taken psychoactive substance. It is often used to overcome sleepiness, and therefore could also harm our sleep at night. This study reviewed 58 epidemiological studies and randomized controlled trials to assess whether caffeine has detrimental effects on sleep. The results demonstrated that the use of caffeine increased sleep latency, decreased sleep duration and sleep efficiency, and worsened perceived sleep quality. The electroencephalographam (EEG) demonstrated changes that are related with less consolidated sleep, such as less slow-wave activity, and more wake time and arousals. Associations were dependent on dose, time and age. Further longitudinal investigations are needed to establish possible causal relations between caffeine use, sleep quality, and health.