How light affects our sleep cycle
Why is it so hard to get a good night’s sleep? To wake up rested and ready for another day? We have learned how important sleep is for our brain, memory, immune system, and for our mental and physical health, but if it is so important, why is it often so difficult to get?
Today, I wanted to take some time to focus a bit on how much light affects our natural circadian rhythm and our sleep cycle!
The Dangers of Blue Light
As we learned in our last blog, the SCN, or suprachiasmatic nucleus in our brain, is very sensitive to light. Before the invention of electricity, our sleep/wake cycles were bound by the sun and moon. While we lengthened the day by using candlelight, the amount of lumens projected by candlelight is so small that it really doesn’t affect our retina or change our bodies’ response. Research suggests that the retina of the eye is most sensitive to the UV light or blue light in the light spectrum. When we are exposed to natural light from the sun, the balance includes the full spectrum of light. Exposure to this bright light for at least 2 hours per day helps to set our internal circadian rhythm and can boost our ability to concentrate, improve our reaction times, and positively affect our moods.
However, recent research focused on the effects of blue light (emitted from our electronic devices and other LED lights) suggests that this light is concentrated in the blue zone. The retina is more sensitive to the blue light spectrum so concentration can interfere with our circadian rhythm. Too much blue light may contribute to other health-related maladies such as damage to the retina. Blue light stimulation tricks our brain into thinking that it is still daytime thus delaying the normal release of hormones associated with sleep, specifically melatonin.
The Magic of Melatonin
Melatonin is produced in the pineal gland deep in the center of the brain. Proper nutrition and hormones such as serotonin and melatonin are what help regulate sleep. It helps to regulate our sleep patterns by starting to release the hormone about 2 hours before bedtime and ramping up the release to produce sleep. Later, melatonin reduces to bring you back to alertness.
This process is interrupted by artificial sources of light. When our brains are stimulated with the artificial blue light, melatonin isn’t released in the normal time frame, thereby directly affecting our ability to go to and stay asleep.
In addition to regulating sleep, according to Dr. Neil Nedley in his book “Proof Positive, Melatonin” has the following potential effects on the body
Providing some protection against free radicals that produce cancer
May delay aging
Improves and supports the immune system
Helps the body to cope with stress and fight depression
Positively regulates our cholesterol levels
Lowers the risk of osteoporosis.
As you can see, sleep regulation is closely tied to our body’s circadian rhythm, the amount of daylight exposure as well as chemical processes in the brain that occur both during daylight and during our sleep time.
What to Do
Blue light has a negative effect on our quality of sleep. If you feel that you’re doing everything right to get a good sleep but still struggle with blue light, here are a few suggestions to reduce blue light exposure:
Try out a pair of glasses that block blue light
Consider shutting off any electronic light source such as TV or computer 1-2 hours before bedtime
Use a red light — consider changing the night lights or lights used in bedrooms from LED to a red light bulb which doesn’t affect the production of melatonin or affect circadian rhythms as much as blue light can.
What Else?
In addition to reducing blue light exposure, we need to consider how our lifestyle choices affect our ability to have a healthy brain and body. The food that we choose to eat, the regular exercise we engage in, the habits of both the use and time of electronic usage, our sleep habits and use of artificial sleep/wake aids. If you consider all of these, you can make a true difference in your health!
Need help with learning new habits? Contact CoreFit Sports Fitness and ask about our wellness program!
Photo by Jonah Pettrich on Unsplash