While Ben Franklin’s adage, “Early to bed, early to rise, makes a man healthy, wealthy and wise,” may be sage advice, it is not a possibility for the more than 7 million shift workers in the United States. These workers, who are caring for hospital patients, maintaining our infrastructure and keeping planes in the air, among other key jobs in our 24/7 world, are unfortunately at risk for health issues.
Shift work disrupts the body’s circadian rhythm, which is responsible for maintaining our roughly 24-hour cycle of drowsiness and alertness. Light impacts this rhythm, which is why we are generally alert in the daytime and sleepy at night, when darkness signals the brain to release melatonin. In a typical circadian rhythm, daylight stimulates peak cognitive and physiological performance and darkness triggers sleep, a time for cell repair and growth and memories consolidation among other functions – so a disruption of melatonin and lack of sleep can cause a host of problems.
In fact, being out of synch with the natural sleep/wake cycle has caused shift workers to experience a chronic condition termed circadian rhythm sleep disorder by the International Classifications of Sleep Disorders, making it hard for these workers to fall asleep and get the shut-eye that their bodies need as well as remain alert when they need to. Rotating shift workers, whose wake/sleep schedule is continually changing, are particularly hard hit by this condition.
Studies show the deleterious effects of shift work on workers, include increased risk of cancer, cardiovascular disease, metabolic syndrome and other physical conditions as well as increased depression and other mental health issues. For example, since sleep affects hormones that regulate appetite and metabolism, lack of sleep can lead to type 2 Diabetes, obesity and related conditions. In addition, fatigue-related accidents are higher for these sleep-deprived shift workers.
How artificial light impacts circadian rhythms
While the natural light/dark cycle of daytime and nighttime acclimates our body to circadian rhythms, artificial light interferes with this natural process. Light is comprised of electromagnetic particles, which range in length and strength and create different colors. Shorter wavelengths emit more energy that longer ones, and blue light, which is the shortest wavelength in the visible spectrum (between 400 and 500 nm) emits a lot of energy.
Businesses, workplaces and institutions of all kinds are embracing blue light for its environmental efficiency. It is most commonly found in compact fluorescent bulbs and LED lights, which emit more blue light than any other artificial light and can reduce energy usage by 75 percent more than traditional incandescent bulbs. Given concerns about global warming and climate change, many municipal and state governments as well as countries around the world are mandating the move from incandescent bulbs to LEDs, making this type of lighting even more prevalent.
With the increased use of LED lights comes increased exposure to blue light. While we need some blue light to facilitate memory, promote healthy cognitive function, and keep us alert during the daytime, we often get enough of that naturally through sunlight. With so much blue light from all of our laptops, mobile phones and other devices – as well as artificial lighting – we are over exposed to blue light.
Because blue light suppresses more melatonin than any other light in the visible spectrum, too much of it can be harmful. While we are all at risk, exposure to blue light at night increases the degree of melatonin suppression, placing shift workers at greater risk for health issues.
Recognizing these issues, hospitals and other organizations are trying to mimic the natural circadian rhythm by recreating lighting that typically occurs over a 24-hour period. Studies have shown that light therapy can help workers remain alert when they need to be by delaying the production of melatonin.
Reducing the harmful effects of blue light
Light therapy experiments use bright light at different intensities and times in an attempt to re-balance circadian rhythms. They aim to delay the circadian rhythms so nighttime shift workers are most tired during the day. Some therapies administer light intensities between 1200 lux and 10,000 lux for of 3-6 hours at night. Another approach uses bright lights for 20 minutes per hour to acclimate the body to the right circadian rhythm and help keep people alert during work hours. Some night workers use blue light filtering glasses to avoid light during their morning drive home. Another study demonstrated the benefits of staying on a sleep/wake schedule even on days off, including the days off and using bright light therapy at different intervals during the night shift.
Lighting manufacturers are trying to develop human-centric (or biofriendly) lighting to align with the body’s circadian rhythms. While some companies are trying to filter out blue light, none of the currently available solutions are able to do this effectively yet. Their solutions are typically more expensive and reduce energy efficiency.
Aurea takes a unique approach by converting traditional low-cost high efficiency blue LEDs into light that is perfectly in sync with the body’s circadian rhythms. It’s the same energy input … only with healthier output, that meets both the mood-based psychological and biological needs of the human body.
To accommodate our needs in today’s 24/7 world the number of shift workers will increase. While they will not be able to follow Ben Franklin’s advice about going to bed and rising early, they can take advantage of new lighting technologies that mimic nature to get their circadian rhythms in balance. That way they can still achieve part of Franklin’s goal and become “healthy and wise.”