Linking exposure to light to the body’s circadian rhythm may help mitigate the ill-effects of shift work.
A research team at Flinders University found that “strategic exposure” to light accelerated body-clock adjustment and improved alertness, performance and sleep after a night shift.
The research report said 15-16 percent of Australian workers reported being shift workers. Most worked rotating shifts with varying schedules.
“Circadian rhythms reflect our body’s internal clocks that control the activity and timing of bodily functions, including our sleep-wake cycle,” Flinders University sleep researcher Hannah Scott said.
“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 Flinders University trial is said to be amongst the first tightly controlled in-laboratory studies to have simultaneously evaluated circadian-lighting effects on markers of body-clock timing, work-shift cognitive performance, and sleep following an abrupt transition to night shift work.
The study was supported by the Defence Science and Technology Group because the findings are of particular interest for shift workers in enclosed environments such as submarines.
“Given the complete lack of normal day-night lighting, shift work on submarines maybe be particularly challenging for the body clock to adjust to,” Dr Scott said.
“We wanted to explore the unique challenges posed by night shifts, particularly the disruption to sleep-wake schedules, which can lead to impaired mental and physical performance, poorer sleep and health issues.
“We found that the use of circadian-informed lighting promoted better improved job performance and sleep for those working irregular hours.”
Nineteen adults participated in the study, which took place in FHMRI Sleep Health’s laboratory under tightly controlled conditions that simulated night work environments.
Participants were exposed to two different lighting scenarios for a period of eight days to compare how their body clock adjusted and how they performed in a series of tasks.
A circadian-informed lighting intervention accelerates circadian adjustment to a night work schedule in a submarine lighting environment has been published in the journal Sleep.
