Lighting helps shift issues
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Circadian lighting drastically improves sleep and performance for night shift workers, a new study finds.
A study led by Flinders University has demonstrated the potential benefits of circadian-informed lighting for night shift workers, offering a possible solution to the challenges associated with working irregular hours.
The research indicates that adjusting artificial lighting to synchronise with natural body rhythms can significantly enhance sleep quality and work performance.
The tightly controlled trial, conducted by the university’s Sleep Health team, is one of the first studies to comprehensively assess the impact of lighting on body-clock alignment, cognitive performance during shifts, and sleep patterns after night work.
Published in the SLEEP journal, the findings highlight how strategic light exposure can help night shift workers adapt faster to their schedules.
“Circadian rhythms reflect our body’s internal clocks that control the activity and timing of bodily functions, including our sleep-wake cycle,” said Dr Hannah Scott, one of the study's authors.
“Shift work causes circadian disruption, for which well-timed light exposure, designed to promote alertness and facilitate circadian adjustment, is one of the most potent methods to help retime the body clock.”
The study simulated night shift work environments with 19 participants, exposing them to two different lighting conditions over eight days.
The circadian-informed lighting included blue-enriched light and dim, blue-depleted light, designed to help the body clock adjust to night work. This was compared to traditional lighting conditions often found in enclosed workplaces, such as submarines.
The researchers evaluated key markers such as melatonin levels, body temperature, cognitive performance, and sleep duration.
The results were promising, with participants’ body clocks adjusting almost one hour faster per day under circadian-informed lighting.
Additionally, participants slept for nearly an hour longer and reported feeling less sleepy during their shifts.
The study is particularly relevant for industries where workers are exposed to dim light for extended periods, such as submariners.
“Given the complete lack of normal day-night lighting, shift work on submarines may be particularly challenging for the body clock to adjust to,” Dr Scott said.
She added that the trial demonstrated how strategic lighting interventions could improve performance and well-being in such environments.
Dr Scott's colleague, Alisha Guyett, emphasised the broader implications of these findings for shift workers in various industries, noting that “strategic lighting interventions can likely be used to enhance the performance, sleep, safety, and well-being of night shift workers exposed to inadequate light during their work shift”.
The trial was supported by the Defence Science and Technology Group and the Research Network for Undersea Decision Superiority, with findings expected to influence future workplace designs where lighting plays a critical role in worker health and efficiency.
The study's outcomes suggest that simple changes in lighting conditions could have a profound impact on the millions of people working night shifts worldwide.