In a breakthrough study, office workers 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 workers with less light exposure in the workplace.
The study highlights the importance of exposure to natural light to health, and stresses the need to switch the workplace lighting with the equivalence of natural daylight exposure for workers.
Seasonal affective disorder (SAD) is associated with winter depression and feeling “normal” or very happy in the summer. Typically, individuals with SAD feel depressed and generally slow down, oversleep, overeat, and crave carbohydrates in the winter. In the summer, these same people feel elated, active, and energetic.
Although many variables may be responsible for SAD, lack of exposure to full-spectrum natural light appears to be the most logical explanation. Full-spectrum light therapy, designed to replicate natural sunlight, has been used to treat both seasonal affective disorder as well as clinical depression.
These benefits may not be limited to SAD and depression. There is a growing body of data showing that exposure to full-spectrum natural light may help anyone feel better. The explanation given is that without natural light exposure, there is a reduced secretion of melatonin by the pineal gland, and an increased secretion of cortisol by the adrenal glands. These hormonal changes are associated with poor sleep quality, stress, and an increased appetite.
In a study conducted by researchers from the University of Illinois and Northwestern University, the impact of daylight exposure on the health of office workers from the perspective of subjective well-being and sleep quality, as well as nighttime activity and sleep-wake patterns were examined.
Participants included 27 workers working in windowless environments and 22 comparable workers in workplaces with significantly more daylight. Windowless environment is defined as one without any windows or one where workstations were far from windows and without any exposure to daylight. Employees with windows in the workplace received 173 percent more natural light exposure during work hours.
Workers in windowless environments reported poorer scores than their counterparts on physical activity and vitality, as well as poorer overall sleep quality. In contrast, workers with windows at the workplace had more physical activity and better sleep quality. Employees with windows in the workplace slept an average of 46 minutes more per night, than employees who did not have the natural light exposure in the workplace.
The researchers concluded that the architectural design of office environments should place more emphasis on sufficient daylight exposure of the workers in order to promote office workers’ health and wellbeing.
Another option for the workplace (and home) is to replace typical lighting with full-spectrum alternatives. The latter is a bit more expensive, but the payoff in health benefits, especially mental health and physical energy, appears to be worth it.
Boubekri M, Cheung IN, Reid KJ, Wang CH, Zee PC. Impact of Windows and Daylight Exposure on Overall Health and Sleep Quality of Office Workers: A Case-Control Pilot Study. Journal of Clinical Sleep Medicine, 2014; DOI: 10.5664/jcsm.3780