Strategies to decrease social jetlag: Reducing evening blue light advances sleep and melatonin

Abstract

The timing of sleep is under the control of the circadian clock, which uses light to entrain to the external light‐dark cycle. A combination of genetic, physiological and environmental factors produces individual differences in chronotype (entrained phase as manifest in sleep timing). A mismatch between circadian and societal (e.g., work) clocks leads to a condition called social jetlag, which is characterized by changing sleep times over work and free days and accumulation of sleep debt. Social jetlag, which is prevalent in late chronotypes, has been related to several health issues. One way to reduce social jetlag would be to advance the circadian clock via modifications of the light environment. We thus performed two intervention field studies to describe methods for decreasing social jetlag. One study decreased evening light exposure (via blue‐light‐blocking glasses) and the other used increased morning light (via the use of curtains). We measured behaviour as well as melatonin; the latter in order to validate that behaviour was consistent with this neuroendocrinological phase marker of the circadian clock. We found that a decrease in evening blue light exposure led to an advance in melatonin and sleep onset on workdays. Increased morning light exposure advanced neither melatonin secretion nor sleep timing. Neither protocol led to a significant change in social jetlag. Despite this, our findings show that controlling light exposure at home can be effective in advancing melatonin secretion and sleep, thereby helping late chronotypes to better cope with early social schedules.

The inner clock—Blue light sets the human rhythm

“…A simple solution that may effectively block and reduce the blue portion of the light spectrum before bedtime are blue light blocking glasses and lenses . Wearing blue light blocking eyewear before and during bed time may effectively attenuate LED induced melatonin suppression and thus can potentially facilitate the adaption to new social schedules and reduce sleep disturbances and their consequences among the general population. Further, a reduction of the blue portion in artificial light during nighttime hours could protect shift workers against disorders such as cancer and cardiovascular disorders.…”

<p>Association Between Weekend Catch-Up Sleep and Metabolic Syndrome with Sleep Restriction in Korean Adults: A Cross-Sectional Study Using KNHANES</p>

“…Although excluded shifting workers, we found that alterations in sleep time during workdays and free days affected sleep timing subsequent day. 17 This misalignment between social and biological time can be described as "social jetlag." 18 The relative social jetlag was calculated as mid-sleep time on free day (MSF) minus mid-sleep time on work day (MSW), and we used the absolute social jetlag to evaluate social jetlag.…”

Sleep Physiology, Circadian Rhythms, Waking Performance and the Development of Sleep-Wake Therapeutics

“…Light treatment also requires light delivery or light input manipulation systems that are easy to use and acceptable to users. Recent light treatment approaches have focused on reducing the blue light content of light to which the retina is exposed (Zerbini et al 2018), and further development of methods by which the 24-h light exposure pattern, at the work place and at home, can be manipulated is a promising avenue for the treatment of some circadian rhythm sleep-wake disorders.…”