Sun used to be our main source of lighting and our evenings were spent in relative darkness. However the invention of artificial lighting sees our evenings being illuminated and we take the access to those lumens for granted.
Artificial Light
All artificial light can interrupt sleep patterns. The body's biological clock works in rhythms. The circadian rhythm is set by the amount of light and dark the body is exposed to. When artificial light is added to your day the body's natural rhythms become disorientated.
Light is detected to the retina. This sends signals to the hypothalamus and when it starts getting dark outside this signals to the body to start creating sleep hormones like melatonin to prepare the body for sleep. However the retina can receive light no matter what time of day it is, so the body doesn't know when to get ready to sleep if we are exposed to this artificial light.
Circadian Rhythms
Each individual has a different circadian rhthym. The average length of these rhythms is 24 and one quarter hours. People who stay up late have a slightly longer circadian rhythm, while the rhythms of early birds fall shorter of 24 hours. According to Dr. Charles Czeisler daylight keeps the body's internal clock aligned with the environment.
The Power of Blue Light
While any light can suppress the secretion of melatonin, blue light at night does this more powerfully. According to research at Harvard blue light suppresses melatonin for twice as long and green light and it also shifts circadian rhythms twice as much.
The Health Risks
Light at night is partly the reason that so many people have disturbed sleep. Even dim light can affect those circadian rhythms and melatonin secretion. Research have link short sleep patterns to increased risk for depression and cardiovascular problems.
Many studies have linked working night shifts and exposure to light at night to cancer, diabetes, heart disease and obesity. It is not exactly sure why it is so bad for us. But we know that exposure to light suppresses the secretion of melatonin that influences the circadian rhythms, and there is some evidence that these low melatonin levels might explain the association with cancer.
What can you do?
To get better sleep the obvious solution is to stop using artificial light altogether. However that isn't possible in modern times, but there are some solutions top help.
- Avoid looking at bright screens 2 hours before bed time
- Expose yourself to lots of bright natural light during the day.
- Use dim red lights for nightlights as this has the least power to disrupt circadian rhythm
- If you work a night shift consider blocking glasses or installing an app that will filter the blue wavelengths at night.
- Dim the brightness on your phone in the evening to prepare your body for sleep
- Avoid looking at your phone in bed.
- Read paper books before bed instead of using a kindle or phone
Bye for now
-Riadh X
