Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness

By A. Chang, Daniel Aeschbach, Jeanne F. Duffy, Charles A. Czeisler. Proceedings of the National Academy of Sciences of the United States of America, 2014

1,300 citations recorded by the source corpus.

Significance The use of light-emitting electronic devices for reading, communication, and entertainment has greatly increased recently. We found that the use of these devices before bedtime prolongs the time it takes to fall asleep, delays the circadian clock, suppresses levels of the sleep-promoting hormone melatonin, reduces the amount and delays the timing of REM sleep, and reduces alertness the following morning. Use of light-emitting devices immediately before bedtime also increases alertness at that time, which may lead users to delay bedtime at home. Overall, we found that the use of portable light-emitting devices immediately before bedtime has biological effects that may perpetuate sleep deficiency and disrupt circadian rhythms, both of which can have adverse impacts on performance, health, and safety. In the past 50 y, there has been a decline in average sleep duration and quality, with adverse consequences on general health. A representative survey of 1,508 American adults recently revealed that 90% of Americans used some type of electronics at least a few nights per week within 1 h before bedtime. Mounting evidence from countries around the world shows the negative impact of such technology use on sleep. This negative impact on sleep may be due to the short-wavelength–enriched light emitted by these electronic devices, given that artificial-light exposure has been shown experimentally to produce alerting effects, suppress melatonin, and phase-shift the biological clock. A few reports have shown that these devices suppress melatonin levels, but little is known about the effects on circadian phase or the following sleep episode, exposing a substantial gap in our knowledge of how this increasingly popular technology affects sleep. Here we compare the biological effects of reading an electronic book on a light-emitting device (LE-eBook) with reading a printed book in the hours before bedtime. Participants reading an LE-eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock, and reduced next-morning alertness than when reading a printed book. These results demonstrate that evening exposure to an LE-eBook phase-delays the circadian clock, acutely suppresses melatonin, and has important implications for understanding the impact of such technologies on sleep, performance, health, and safety.

Subfields: Endocrine and Autonomic Systems, Experimental and Cognitive Psychology, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/d338de6a48d1caf5a1a89f8fabcb14024f7baa2a

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In Endocrine and Autonomic Systems

Davide M. Dominoni

In Experimental and Cognitive Psychology

In Global and Planetary Change

Citations in the corpus

Association between light at night, melatonin secretion, sleep deprivation, and the internal clock: Health impacts and mechanisms of circadian disruption (2017, background): “Even low intensity light, as emitted by recent technologies such as LEDs, computer screens or televisions, mobile phones, and tablets is capable of acting on the clock, thus leading to a phase delay and a slowing of melatonin secretion [21].”
Circadian Rhythm and Sleep Disruption: Causes, Metabolic Consequences and Countermeasures (2016, neutral): “cadian rhythm and sleep disruption (227).”
Light Pollution, Circadian Photoreception, and Melatonin in Vertebrates (2019, methodology): “More than one light source was used in several studies [122,123,126,139,147].”
Identifying Objective Physiological Markers and Modifiable Behaviors for Self-Reported Stress and Mental Health Status Using Wearable Sensors and Mobile Phones: Observational Study (2018, background): “Second, lighting from the interaction with mobile phones or emailing late at night could disturb the biological circadian clock and increase alertness, both of which can influence sleep patterns [27,28].”