Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness.
Proc Natl Acad Sci U S A
; 112(4): 1232-7, 2015 Jan 27.
Article
em En
| MEDLINE
| ID: mdl-25535358
ABSTRACT
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.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Leitura
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Sono
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Transtornos do Sono-Vigília
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Iluminação
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Ritmo Circadiano
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article