Light and darkness are signals that regulate biological clocks to coordinate changes in your body that collectively are called “circadian rhythm”. The most obvious light influenced circadian rhythm is our sleep and awake cycle. The biological clocks are composed of specific molecules in all parts of your body that independently can respond and regulate physiology in response to light or darkness. The master clock is a center in your brain called the Suprachiasmatic Nucleus (SCN) and it integrates various other clocks in the human body. This biological clock can be altered in certain situations as “jet lag” and it can take a few days to reset it.

Melatonin – an important hormone for good sleep

The cycle of light and darkness controls the release of the hormone melatonin in the brain. The levels of melatonin are low during the daytime and rise before sleep to promote calm and quietness. The natural cycle of melatonin is disturbed by artificial lighting from above and electronic devices like computers and smartphones. The blue and green light lowers the levels of the hormone and will make it harder to fall and stay asleep during the night. Disturbing the natural sleep cycle has very detrimental effects and will, for example, have direct negative effects on your metabolism and eating behavior. 

Promoting melatonin and good sleep

Melatonin can be taken as a supplement but is only recommended for short periods if you are struggling with falling asleep or correcting a jet lag. There are some key behaviors to long term boost your natural melatonin. 

  • Get some sunlight during day time. Keeping the natural cycle of daylight stimulates melatonin release in the evening. Combining this with a workout or maybe just a walk outside is very beneficial. 
  • Turn off bright lights 1-2 hours before sleep. Avoiding bright lights from above or bright electronic screens will allow the natural melatonin cycle to occur. Most smartphones now have a “night mode” you can activate where the green/blue light is reduced to avoid disturbing the sleep cycle.
  • Try to follow the natural light/dark cycle by getting ready for sleep when it gets dark. This can help you to more often wake up earlier with sunrise and avoid alarms more often.
  • Lower temperature where you sleep. One of the actions of melatonin is to lower your body temperature which induces drowsiness. Keeping your bedroom cool promotes better sleep.