Your master biological clock can be found inside the suprachiasmatic nucleus or the SCN of your brain. This is a part of your hypothalamus. Depending on the signals of light and darkness, the SCN dictates to your pineal gland when it is actually time to secrete melatonin and when to stop doing so.
In short, your melatonin levels increases and decreases with light and darkness. Tied to this rhythm of light and dark are your physical health and mental health.
Not many people know that when it gets dark, the levels of your melatonin increase, which results to you being tired when the sun begins to set. On the contrary, when you are exposed to artificial lighting at night (including light emitted by electronic gadgets and TV screens) you may find it quite difficult to fall asleep. This is because of suppressed melatonin levels.
Simply put, a lot of sleep problems can be solved by just making sure that you avoid light exposure when it is bedtime and choosing to sleep in complete darkness.
You may be wondering, “What about dim lighting?” It’s understandable because a lot of people are uncomfortable with the idea of sleeping in total darkness. But you should know that being exposed to very dim light while sleeping (although you may argue that it does not impair your sleep at all) actually affects your brain function as well as its cognition during daytime.
A study was conducted to check the effects of minute amounts of light when one sleeps and how it relates to one’s cognition. In the study, 20 healthy men slept in complete darkness (in a laboratory) for two consecutive nights. On the third night, they were exposed to a dim light of five or 10 lux.
In the working memory tests conducted while undergoing fMRI or functional Magnetic Resonance Imaging, exposure to five lux lighting showed no significant effects on the brain’s activity. However, sleeping under 10-lux conditions decreases activation in an area of your brain that is involved in attentional control, response inhibition, and detection of relevant cues during a task.
This means that past a specific point of very dim lighting, exposure to nighttime light can directly affect your brain function, especially your cognition and working memory.
JUST BECAUSE THERE ARE NO SYMPTOMS DOESN’T MEAN YOU’RE NOT AFFECTED
You may be thinking, “I am not affected by this”, simply because you are not noticing any problems and you believe your brain is working as it should. However, as the study discovered, despite the lack of manifestation of changes, your brain is still not working optimally. One suspected cause is the possibility that light exposure during sleep induces cognitive dysfunction.
The study also shows that nighttime exposure to light of even just 5-lux inhibits an important brain rejuvenator, which causes shrinkage of neurons in the hippocampus, a region of your brain involved in the storage of long-term memory as well as emotional regulation.
How do you protect your brain health?
Practice sleeping in total darkness. That’s a good start! You can also visit Sloan Natural Health Center for a consultation. We have programs that would greatly benefit your brain and your overall health!
