Why is light important?
Since time began, humans have responded to their natural environments & internal bodyclocks, dictated primarily by the transition of light and dark. We often feel happier in summer months and our skin is healthier when the sun is out for longer and there is more natural daylight available. When there is strong and regular light available, the cells in our brain regulate our bodyclocks by controlling the correct levels of hormones that manage our waking and sleeping patterns, our mind, mood and wellbeing.
As we have reached the 21st century, our busy lives mean that working shifts, working in falsely lit office environments and being outdoors less can negatively impact our internal bodyclock function which is dictated by light, especially during the winter months. This internal bodyclock is known as our circadian rhythm. Regular volumes of light at strong levels are important in order to maintain the regulation of this internal biological clock, which if disrupted can cause a number of symptoms that can affect our health and wellbeing.
The circadian rhythm
The Circadian Rhythm is an internal 24 hour bodyclock that regulates the biochemical, physiological or behavioural processes of humans, plants and animals - or any living organism for that matter. This 24 hour cycle synchs with light and dark, or wake and sleep, and allows the cyclical release of hormones that affect our mood, energy levels and general bodily functions.
As the key environmental factor that affects our inbuilt human bodyclock is daylight, when the seasons change and less light is available (combined with our hectic 21st century jobs and lives), this can cause our circadian rhythm to become imbalanced. An imbalanced circadian rhythm can cause a whole host of issues, ranging from mood swings, irritability and over-eating, to sleep disorders, jet lag and tiredness.
When we wake naturally to daylight and without a shrill alarm to shock us, our bodies have already started to produce cortisol. It is the production of cortisol that tells our body it’s time to wake up – and so we wake naturally, keeping our bodyclock in synch. Similarly, when it’s dark and time to go to bed, our bodies produce the sleep hormone melatonin, which signals our body to fall asleep – again keeping our human bodyclock in synch.
It is when we work in falsely lit offices, wake up when it is still dark outside (during winter months or for shift workers) and to a loud alarm which shocks our system that our circadian rhythm can become out of check, which can cause some or all of the symptoms described above.