The influence of blue light on sleep, performance and wellbeing in young adults: A systematic review

Abstract

Introduction: Blue light from electronic devices has a bad reputation. It has a wavelength which may influence our circadian rhythm and cause bad sleep. But there are other aspects of blue light exposure which are often overlooked, for example, it may influence performance and wellbeing. However, few resources summarize its effects systematically. Therefore, the goal of this systematic review was to distil the present evidence on blue light exposure and its influence on sleep, performance and wellbeing and discuss its significance for athletes.Methods: The databases that were searched were Cochrane, Embase, Pubmed, Scopus, and Virtual Health Library. The studies included investigated the influence of blue light exposure on either sleep, performance, wellbeing or a combination of those parameters on healthy humans. Quality assessment was done based on the quantitative assessment tool “QualSyst.”Results: Summarizing the influence of blue light exposure, the following results were found (expressed as proportion to the number of studies investigating the particular parameter): Fifty percent of studies found tiredness to be decreased. One fifth of studies found sleep quality to be decreased and one third found sleep duration to be decreased. Half of the studies found sleep efficacy to be decreased and slightly less than half found sleep latency to be increased. More than one half of the studies found cognitive performance to be increased. Slightly more than two thirds found alertness to be increased and reaction time to be decreased. Slightly less than half of the studies found wellbeing to be increased.Conclusion: Blue light exposure can positively affect cognitive performance, alertness, and reaction time. This might benefit sports reliant on team-work and decision-making and may help prevent injury. Blue light might also have negative effects such as the decrease in sleep quality and sleep duration, which might worsen an athlete’s physical and cognitive performance and recovery. Further research should explore if blue light can improve sleep, performance and wellbeing to significantly benefit athletic performance.

ICNIRP Statement on Short Wavelength Light Exposure from Indoor Artificial Sources and Human Health

“…Experimental studies on the effects of SWL exposure on alertness or sleepiness have shown conflicting results. This is evident from the most recent systematic reviews (Souman et al 2018; Xu and Lang 2018; Mu et al 2022; Silvani et al 2022) assessing the effect of SWL on these outcomes. Mu et al (2022) performed the only review with a meta-analysis.…”

“…In summary, the results by Souman et al (2018) and Xu and Lang (2018) indicate that nighttime exposure to SWL may influence alertness slightly more than daytime exposure. Silvani et al (2022) only reviewed studies that examined effects of SWL but did not specify the time of day of the exposures. They found that more studies reported alerting effects vs. no effects, and this was similar for both subjective and objective alertness.…”

“…They found that more studies reported alerting effects vs. no effects, and this was similar for both subjective and objective alertness. It should also be noted that some of the included studies found an effect for subjective but not objective alertness or vice versa (Xu and Lang 2018), and a few studies reported reduced rather than increased alerting effects from exposure to SWL (Souman et al 2018; Silvani et al 2022).…”

“…In addition to assessing immediate alerting effects, Silvani et al (2022) reviewed effects of exposure to SWL on sleep, and Xu and Lang (2018) included two studies where effects on sleep were assessed. More than half of the studies reported no effect of prior exposure to SWL on sleep quality, latency or duration.…”

Determination of intensity and spread of light to the surrounding in conventional phototherapy and comparison with novel converging photo unit — an observational study

“…Healthcare workers caring for the baby on phototherapy are constantly exposed to blue light and thereby its side effects. Altered circadian rhythm results in disruption in the sleep-wake cycle affecting healthcare providers particularly working during the night shift [4][5][6][7].…”