Study objectives: Near-infrared light exhibits several therapeutic properties, but little is known about the benefits to sleep and daytime function. The purpose of this study was to investigate the effects of red and near-infrared exposure before bed on sleep and next-day function.
Methods: Thirty adults (30-60 y) with a self-reported sleep complaint but without a sleep disorder participated in a randomized, sham-controlled study for a duration of 5 weeks. After a 2-week baseline period, participants wore either a cervical red light/near-infrared-emitting collar (combined: 660 nm, 740 nm, 810 nm, and 870 nm) or sham device every other night before bed for 3 weeks. Sleep was measured using actigraphy and sleep diaries. Mood and performance were assessed using weekly self-reported surveys and debrief interviews.
Results: Objective sleep parameters, as measured by actigraphy, did not differ between the active or sham groups, but improved self-reported sleep, as well as perceived improvements in relaxation and mood, were observed among active but not sham users. Both active and sham users improved in Insomnia Severity Index score by the end of the trial.
Conclusions: Red and near-infrared exposure to the head and neck before bed may offer potential therapeutic benefits to sleep and daytime function, but further work needs to be done to determine optimal dose parameters, wavelengths, and milliwatt power level.
Clinical trial registration: Registry: ClinicalTrials.gov; Name: Phase II Study-Trial of a Phototherapy Light Device to Improve Sleep Health (PHOTONS); URL: https://clinicaltrials.gov/ct2/show/NCT05116358; Identifier: NCT05116358.
Citation: Kennedy KER, Wills CCA, Holt C, Grandner MA. A randomized, sham-controlled trial of a novel near-infrared phototherapy device on sleep and daytime function. J Clin Sleep Med. 2023;19(9):1669-1675.
Keywords: actigraphy; insomnia; near infrared; phototherapy; sleep; wearables.
© 2023 American Academy of Sleep Medicine.