When we were hunter gatherers, we would rise at dawn and be outdoors. We would bed down at sunset or just after. After sundown our only light source was fire.
While society has changed vastly since then, our bodies have not, and the importance of having a day/night pattern is still paramount for our mental and physical wellbeing.
Our bodies have an internal master clock called a circadian rhythm which runs constantly in the background to carry out essential processes in the body. The word circadian comes from the Latin “circa diem” which means “around the day”. Our master clock is directly influenced by cues such as temperature, exercise, social activity, but light is the most powerful influence. All living species have a circadian rhythm. It is what makes flowers open and close, it is what makes certain animals be nocturnal, or hibernate.
When our body clock is in harmony with our environment, we get regular and restorative sleep. However, when we are out of sync, it can cause significant sleep problems. This has a knock on effect on our physical and mental health. While artificial light has been revolutionary for many things, it’s overuse, especially during evening and night can cause havoc to our bodies as our brain starts to release the wrong chemicals at the wrong time.
So how can we address this? Here are five ways:
1) Get daylight exposure in the morning.
It has been shown that if we can get at least 30 minutes of daylight exposure in the morning, (even if it’s cloudy), this helps to synchronise our internal clocks. The sunlight hits light receptors at the back of our eyes. These receptors send a signal to our brain to tell us it is morning and generates alertness. Our brain then synchronises our internal biological rhythms. A perfect way to do this is a morning walk.
2) Bright light therapy
For the winter when mornings are still dark, and/or if you are unable to go for a morning walk, consider investing in a bright light therapy lamp. Bright light therapy (BLT) was initially used for treating Seasonal Affective Disorder (SAD) which is a type of depression linked to the change in season. Treatment has shown to be effective within a few days. It is now also being used for general depression and other conditions with good results. BLT lamps are widely available and affordable nowadays.
3) Blue blocking glasses:
Blue blocking glasses are glasses that can be worn day and night to block out “junk light”. They are useful if you are in front of a screen for several hours a day or to block out artificial light in the evening. There are several companies selling them now. Do your research and buy from a reputable company.
3) Limit light before bed.
As sunset comes and night falls, the darkness tells our master clock to start producing melatonin – a hormone that promotes sleep. Artificial light exposure at night interferes with our circadian rhythm. A reduction in melatonin has been shown to increase hunger and weight gain. Dim your house lights in the evening or use candles instead.
3) Put down devices at night.
The light emitted from devices such as smart phones and computer screens also affects our body clock. In the evenings use the “night shift” on your smartphone. The colour balance of the screen can be altered to warmer more orange colours (like sunset!) Turn them off completely an hour before bed and keep them out of the bedroom.
Wishing you all health and happiness,
Dr Maria Amasanti