Light-emitting diodes (LEDs) have become quite popular in recent years since they can provide better lighting are more energy efficient, compared with incandescent bulbs, but even though they are helpful, there is also a downside: they affect sleep.
In a new study – published the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism – the researchers found that all artificial light – fluorescent bulbs, LEDs and incandescent bulbs – can have a negative effect on sleep and they interrupt regular sleep patterns.
The circadian rhythm, which can be defined as the body’s biological clock that displays an endogenous oscillation of about 24 hours, plays an important role in the timing of various physiological processes. These include: feeding and sleeping patterns, cell regeneration, brain activity, and hormone production.
Natural sunlight makes the hypothalamus area of the brain sets its sleep patterns. According to the National Sleep Foundation, when it starts getting dark outside, signals sent by the retina to the hypothalamus are then sent to the body, which in turn starts releasing sleep hormones, such as melatonin (hormone which in animals anticipates the daily onset of darkness). In the morning, the body is told to produce hormones, like cortisol.
Circadian rhythms become confused when humans are exposed to artificial light as well. No matter what time of the day it is, the retina is still able to receive light, which makes the body not known when to get ready for sleep, according to the researchers.
Researchers have found that melatonin production was suppressed by 85 percent due to exposure to room light during the night. Moreover, the blue lights from LEDs boost mood, attention, and reaction times, which could be great during daytime, but not at night when the body needs to rest, experts at Harvard Medical School said.
Blue light hindered melatonin production more than any other type of light, according to the researchers. The shorter wavelengths in blue light might be the reason why the body produces less melatonin.
David Earnest, a professor and circadian rhythms expert at the Texas A&M Health Science Center College of Medicine, said that the human circadian system can be impacted by a spectrum of wavelengths and blue lights appears to be the most sensitive side of that spectrum.
Another study that was conducted by researchers at the University of Toronto found that people who wore glasses – that were able to block blue light wavelengths – during night shifts, produced more melatonin, compared to those who did not. Other researchers have also found that blue light wavelengths increase alpha waves, which generate alertness, and they suppress delta brain waves, which are known to induce sleep.
Dr. Robert Oexman, director of the Sleep to Live Institute, said that to prevent sleeping problems, people should avoid exposure to blue light – from tablets, computers, TVs, laptops or smart phones – thirty to sixty minutes prior to going to bed.
Andrew Simon, a naturopathic physician at the Bastyr Center for Natural Health, stated that to help encourage the body’s natural sleep/wake cycle, people could get new smart home tech solutions that are able to make the lights around the house turn off gradually or at a certain time.
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