The recent trial on circadian-informed lighting, which aligns artificial light with natural biological rhythms or a person’s ‘body-clock’, reveals that it can greatly enhance sleep quality and work efficiency for night shift employees.
The recent trial on circadian-informed lighting, which aligns artificial light with natural biological rhythms or a person’s ‘body-clock’, reveals that it can greatly enhance sleep quality and work efficiency for night shift employees.
The Flinders University trial stands out as one of the first well-controlled laboratory studies to examine how circadian lighting influences body-clock markers, cognitive performance during work shifts, and sleep quality, particularly after a sudden switch to night shift work.
Two papers stemming from the trial are published in the Oxford University Press SLEEP journal. The findings indicate that well-timed light exposure sped up body-clock adjustments and improved alertness, performance, and sleep following night shifts.
According to Dr. Hannah Scott, a sleep researcher at Flinders University and co-author of Circadian-informed lighting improves vigilance, sleep, and subjective sleepiness during simulated night shift work, “Circadian rhythms are our body’s internal clocks that guide various functions, including the sleep-wake cycle.”
“Shift work disrupts these rhythms, and properly timed light exposure can significantly aid in re-adjusting our body clocks to promote alertness and facilitate adaptation.”
In Australia, around 15-16 percent of the workforce are shift workers, with rotating shifts being the most common type for both men and women.
Supported by the Defence Science and Technology Group and the Research Network for Undersea Decision Superiority, these findings are particularly relevant for workers in confined environments like submarines, where lighting is often low.
Dr. Scott notes, “Without the usual day-night lighting, shift work on submarines can be especially tough for body clock adjustments.”
“We wanted to delve into the distinctive challenges of night shifts, especially how they disrupt sleep-wake schedules, which can lead to reduced mental and physical performance, poor sleep, and health issues.”
“Our research showed that circadian-informed lighting led to significant improvements in job performance and sleep for those on irregular hours,” explains Dr. Scott.
The study involved 19 adults who participated in a controlled environment at FHMRI Sleep Health’s lab, simulating night work conditions.
Participants experienced two different lighting conditions over eight days to see how their body clocks adjusted and how they performed on various tasks.
The circadian-informed lighting involved blue-enriched and dim, blue-reduced conditions aimed at aiding the body clock’s adaptation to night work, while the traditional dim, blue-reduced lighting replicated the typical lighting found on submarines.
The research team monitored essential circadian indicators such as melatonin levels and core body temperature, along with cognitive performance and sleep outcomes.
Remarkably, during four consecutive simulated night shifts, the circadian-informed lighting helped participants’ body clocks adjust almost one hour faster each day compared to standard lighting.
Lead author Alisha Guyett of A circadian-informed lighting intervention accelerates circadian adjustment to a night work schedule in a submarine lighting environment stated that the results are very encouraging for night shift workers and employers.
“The clear advantages of circadian-informed lighting on sleep and alertness are evident from this study. Our results suggest that lighting interventions can improve the performance, sleep quality, safety, and well-being of night shift workers experiencing poor lighting during their shifts,” said Ms. Guyett.
“These lighting interventions significantly sped up the adjustment of participants to night work, highlighting their potential to enhance the health and performance of those who consistently work night shifts.”
Notably, participants under circadian-informed lighting obtained nearly an hour more sleep compared to those in standard lighting conditions and reported feeling less sleepy during their shifts.
To gauge alertness, participants underwent the Psychomotor Vigilance Task (PVT), a measure of behavioral attention. Those exposed to circadian-informed lighting made half as many mistakes (7.4 lapses) compared to those under standard lighting (15.6 lapses).
Professor Peter Catcheside, a senior researcher at Flinders Health and Medical Research Institute: Sleep Health, commented, “This study underscores the significance of the circadian system and circadian-friendly lighting in addressing the substantial challenges posed by shift work.”
“It complements existing knowledge about optimizing workspaces with these interventions to enhance performance, safety, and well-being in today’s workforce.”
“The implications of these findings for lighting conditions in submarines are notable, as well as for mining and other work environments where poor lighting may hinder shift workers’ ability to adjust their body clocks effectively,” he added.
