Excerpt from Science correspondent Sarah Knapton, the Telegraph, August 2014
Workers who struggle to get to sleep at night often blame the office. But rather than the stress and strain of the workplace, their insomnia might be more closely linked to the position of their desk.
Sitting too far from a window in an office can knock 46 minutes off a normal night’s sleep, a study has found. Researchers discovered that workers forced to toil in windowless rooms had a poorer quality of life and more erratic sleep patterns, compared with those with access to daylight. The findings, published in the Journal of Clinical Sleep Medicine, suggest the working environment may be crucial in setting the body’s internal clock.
Dr Neil Stanley, an independent sleep expert, said “Light is essentially the thing that tells our bodies to be awake and dark tells them to go to sleep. The problem with office lighting is that it is not made up of ‘blue’ light, which is the wavelength of light you get from the sun and which controls your body clock. So you could have a very well-lit office but it does not have the same effect because it’s artificial and does not contain blue light”.
Better designed offices could boost the physical and mental health of workers, researchers said. “We suggest that architectural design of office environments should place more emphasis on sufficient daylight exposure for workers in order to promote health and well-being”, said Dr Ivy Cheung, of the department of neurology, Northwestern University, Chicago. “Office workers with more light exposure at the work place also tended to have better activity and a better quality of life”.
The scientists said that a sunny day provided a light intensity of about 10,000 lux, a unit of illuminance. However, indoor office lighting typically provides only about 300 to 500 lux.
One in three Britons suffers from poor sleep, with stress, computers and taking work home often blamed for the lack of quality slumber.
However, the cost of all those sleepless nights is more than just bad moods and a lack of focus. Regular poor sleep raises the risk of serious medical conditions such as obesity, heart disease and diabetes, and it can shorten life expectancy.
Scientists recruited 49 office employees, just over half of whom spent the day in mostly windowless environments. Each one was questioned on sleeping patterns, physical activity and general lifestyle. Some of the volunteers wore high-tech watches around the clock for a fortnight to measure their light exposure, levels of physical activity and sleep times.
Those with the most work-time light exposure slept an average of 46 minutes more per night than their light-deprived colleagues. They also scored better on a sleep quality scale and reported fewer night time disturbances.