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Cited by 114Circadian rhythm and melatoninSleep and related disordersSleep and Work-Related Fatigue

Phase advancing the human circadian clock with blue-enriched polychromatic light

Open access
Smith, Mark R., Revell, Victoria L., Eastman, Charmane I.·2009·Sleep Medicine
DOI 10.1016/j.sleep.2008.05.005PMC PMC2723863
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Abstract

Background Previous studies have shown that the human circadian system is maximally sensitive to short-wavelength (blue) light. Whether this sensitivity can be utilized to increase the size of phase shifts using light boxes and protocols designed for practical settings is not known. We assessed whether bright polychromatic lamps enriched in the short-wavelength portion of the visible light spectrum could produce larger phase advances than standard bright white lamps.Methods Twenty-two healthy young adults received either a bright white or bright blue-enriched 2-h phase advancing light pulse upon awakening on each of four treatment days. On the first treatment day the light pulse began 8h after the dim light melatonin onset (DLMO), on average about 2h before baseline wake time. On each subsequent day, light treatment began 1h earlier than the previous day, and the sleep schedule was also advanced.Results Phase advances of the DLMO for the blue-enriched (92+/-78 min, n=12) and white groups (76+/-45 min, n=10) were not significantly different.Conclusion Bright blue-enriched polychromatic light is no more effective than standard bright light therapy for phase advancing circadian rhythms at commonly used therapeutic light levels.

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  • Studies by Smith et al. demonstrated that blue-enriched white light (17 000 °K) does not outperform standard white light (4100 °K) in phase-advancing or phase-delaying effects.

    “Studies by Smith et al. [32,33], have demonstrated that, in a similar way, frequently used bright-light therapy photon densities (4.2 vs. 4.9 10E15 photons/cm2/s), blue-enriched white light (17 000 °K) does not outperform standard white light (4100 °K) in phase-advancing or phase-delaying effects.”

    From Low-intensity blue-enriched white light (750 lux) and standard bright light (10 000 lux) are equally effective in treating SAD. A randomized controlled study (2011) · cites this paper as [33]

    The Methods (Light Treatment; page unavailable) report the stated color temperatures and photon densities, and the Discussion says blue-enriched light did not produce larger phase advances than standard white light. This paper used a phase-advancing protocol, however, and does not establish the claimed comparison for phase delays. Its Discussion mentions a different phase-delay study but not a delay comparison of these two lights. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • NIF light effects at shorter wavelength via novel photoreceptors containing the photopigment melanopsin appear to strongly impact the human circadian timing system.

    “NIF light effects at shorter wavelength via novel photoreceptors containing the photopigment melanopsin appear to strongly impact the human circadian timing system [11,12].”

    From Dawn simulation light impacts on different cognitive domains under sleep restriction (2015) · cites this paper as [12]

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Authors
Smith, M. R., Revell, V. L., & Eastman, C. I.
Affiliations
  • Rush University Medical Center (US)
  • University of Surrey (GB)
Corresponding author
Eastman, Charmane I.
ORCID
Venue
Sleep Medicine
Publisher
Elsevier BV
Published
2009-03
Volume
10
Issue
3
Pages
287-294
ISSN
1389-9457 (ISSN-L)
DOI
10.1016/j.sleep.2008.05.005
PMC
PMC2723863
OpenAlex
W2077173426
Cited by
114
References
49
Citations by year
2025: 3 · 2024: 4 · 2023: 7 · 2022: 5 · 2021: 8 · 2020: 5 · 2019: 1 · 2018: 6 · 2017: 6 · 2016: 4 · 2015: 10 · 2014: 7 · 2013: 8 · 2012: 9
FWCI
4.61
Type
journal article
Language
en
Open access
Licence
www.elsevier.com/tdm/userlicense/1.0/ (tdm)
Locations
  • Sleep Medicine (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • Open Research (University of Surrey) (submittedVersion)
  • Surrey Research Insight Open Access (The University of Surrey) (submittedVersion)
Funders
  • National Institutes of Health
  • National Institute of Nursing Research (R01NR007677)
Topics
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and Work-Related Fatigue
Keywords
circadian phase advance, blue-enriched light, polychromatic light, bright light therapy, dim light melatonin onset, short-wavelength light, circadian rhythm
MeSH terms
Adult, Circadian Rhythm, Female, Humans, Light, Lighting, Male, Melatonin, Phototherapy, Sleep, Wakefulness, Young Adult

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