Employees that work in offices which are naturally lit enjoy better physical and mental health than those that work in artificially lit offices, a new study finds.
There's a reason why health officials often recommend spending time outdoors instead of being cooped up inside the house! Natural light is good for health. Supporting this theory, a new study found that employees with more light exposure at the office had longer sleep duration, better sleep quality, more physical activity and better quality of life compared to office employees with less light exposure in the workplace.
"There is increasing evidence that exposure to light, during the day, particularly in the morning, is beneficial to your health via its effects on mood, alertness and metabolism," said senior study author Phyllis Zee, a Northwestern Medicine neurologist and sleep specialist, in a press statement. "Workers are a group at risk because they are typically indoors often without access to natural or even artificial bright light for the entire day. The study results confirm that light during the natural daylight hours has powerful effects on health."
The study included 49 day-shift office workers. Among them, 27 worked in windowless offices and 22 in offices with window. Using self-reported forms and the Pittsburgh Sleep Quality Index (PSQI), researchers measured health-related quality of life and sleep quality. Researchers also used a device called actigraphy to measure light exposure, activity and sleep.
"Light is the most important synchronizing agent for the brain and body," said Ivy Cheung, co-lead author and Ph.D. candidate in neuroscience in Zee's lab at Northwestern. "Proper synchronization of your internal biological rhythms with the earth's daily rotation has been shown to be essential for health."
Researchers found that employees working in offices with windows received 173 percent more white light exposure during work hours and slept an average of 46 minutes more per night than employees who did not have the natural light exposure in the workplace. There also was a trend for workers in offices with windows to have more physical activity than those without windows. Workers without windows reported poorer scores than their counterparts on quality of life measures related to physical problems and vitality, as well as poorer outcomes on measures of overall sleep quality and sleep disturbances.
"Architects need to be aware of the importance of natural light not only in terms of their potential energy savings but also in terms of affecting occupants' health," said co-lead author Mohamed Boubekri, an associate professor of architecture at the University of Illinois at Urbana-Champaign. "A simple design solution to augment daylight penetration in office buildings would be to make sure the workstations are within 20 to 25 feet of the peripheral walls containing the windows. Daylight from side windows almost vanishes after 20 to 25 feet from the windows."
A previous study also highlighted the benefits of exposure to daylight in the mornings to lose weight. The researchers found that people who had most of their daily exposure to even moderately bright light in the morning had a significantly lower body mass index than people who were exposed to sunlight later in the day.
The Correlations Between Light Exposure And Lower BMI
Insufficient exposure to morning de-synchronizes an individual's internal body clock. This alters metabolism and leads to weight gain.
"We focus on how too much light at night is bad; it's also bad not to get enough light at the appropriate time during the day," health experts say, according to Los Angeles Times.
500 lux of light is the minimum threshold to maintain a lower BMI. Owing to the American lifestyle, which is predominantly indoors, people get about 200 to 300 lux of light daily. However, outdoor light is more than 1,000 lux of brightness even on a cloudy day.
Since most offices and schools are poorly lit, researchers recommend that these buildings should consider having more widows that allow natural light to enter the rooms. Indoor lighting should also be improved and employees and students should be encouraged to go outdoors for breaks.
Night Shift Workers Are At A Higher Risk of Obesity
A previous study found that people who work night shifts are at a higher risk of obesity and diabetes. While the study highlighted lack of sleep as the main cause of weight gain, this study can help throw more light on the subject.
"Since night workers often have a hard time sleeping during the day, they can face both circadian [body clock] disruption working at night and insufficient sleep during the day," Dr Orfeu Buxton, lead researchers of the previous study said, according to BBC News. "The evidence is clear that getting enough sleep is important for health, and that sleep should be at night for best effect."
People who work night shifts are generally sleeping through the day. Hence, there are lesser chances that they get adequate exposure to natural morning light.
Another benefit of being exposed to morning light is that it enhances sleep quality, eradicating obesity problems yet again. The light regulates a person's biological clock and keeps it on track, according to a health report.
The current study was published online in the Journal of Clinical Sleep Medicine in June. The research was funded by the National Heart, Lung and Blood Institute and the National Institute on Aging, of the National Institutes of Health.
