The Museum’s Health Sciences Department is partnering with the University of Colorado Anschutz Medical Campus to publish a monthly series on the Museum blog called “Know Health”. The articles focus on current health topics selected by CU’s medical and graduate students in order to provide both English and Spanish speaking communities with current, accurate information. The posts in the “Know Health” series are edited versions of articles that first appeared in Contrapoder magazine. Thank you to the students at the University of Colorado Anschutz Medical Campus for bringing these stories to life.
(aka Dr. Nicole Garneau, chair and curator, Health Sciences Department)
The dark side of blue light: How electronics affect our sleep
By Christy Beitzel, University of Colorado School of Medicine
Since Thomas Edison developed the light bulb in 1879, our world has been flooded with artificial light. This exposure continues to grow as our reliance on smart phones, tablets and TVs increase. Although Edison himself once said light “does not affect the soundness of sleep,” but this may not be true. Electronics emit blue light, which our brains interpret as daylight. During the day, exposure to blue light is fine but before bedtime can significantly impact our sleep. People with disrupted sleep cycles are significantly more likely to use sleep aids, have poor cognitive functioning, and poorer health outcomes.
Natural Sleep/Wake Cycles
Our body’s natural cycle of fluctuating between sleep and wakefulness is called our circadian rhythm. This ‘master-clock’ is controlled by a part of the brain called the hypothalamus, which sends signals that keep your body doing all the things it needs to survive. The cells that keep the master-clock ticking in the hypothalamus respond to a hormone called melatonin, which is sensitive to light coming in from the eyes. Melatonin is at its highest at night when you feel sleepy, and lowest at mid-day when you feel most awake.
Why Screen Time Is Keeping You Up
Blue light has a profound influence on our circadian rhythm. Exposure to blue light at night resets your brain cells by changing how much melatonin is made in your brain. This tricks your brain into thinking its daytime and that you should be awake. Scientists aren’t exactly sure why increased light exposure is so harmful, but some studies suggest longer exposure to blue light causes a continual decrease in hormone release, leading to poor sleep habits. And sleep disorders have been long known to associate with many psychological and physical ailments such as obesity and depression.
So how can we get back to our natural brain rhythms? A study from the University of Colorado-Boulder suggests ditching the electronics and getting outside can help. Researchers conducted an experiment where 8 campers went into the Rocky Mountains for one week with only natural light sources. By the end, all campers had reset their circadian rhythm and found they naturally fell asleep when the sun went down and awoke when the sun came up. This study suggests that to get better sleep, people need more time outside and fewer hours around artificial lighting from electronics.
Now you may not be able to live your life without artificial light, and probably none of us are going to move into the wild, but we can take some notes from scientists to get a better night’s sleep. Here are a few ways we can keep our clocks ticking more naturally:
- Shut down electronics 1-2 hours before bed, or at least turn down the brightness of your screen.
- Increase the amount of sunlight we are exposed to during the day, a great way is to get a walk at lunchtime when alertness is at its peak.
Clearly technology has offered us many benefits, but like most things, moderation is key. Millions of years of evolution have trained our internal clocks to be set by the natural world around us. So if you’re feeling worn down maybe it’s time to get out and explore the great outdoors!