Circadian Biology
& Light

Circadian Biology And Light



The way you use light can affect your health

There has been explosion in the amount of research into light, both natural light and artificial light and its effect on physiology and health.

The research comes from various areas including myopia control, chronobiology, photobiomodulation, circadian dysfunction, delayed sleep wake phase disorder, mental health, cardiovascular, vitamin D and auto immunity to name a few.

An assumption has been made that living indoors under artificial light and disregarding daily and seasonal light patterns does not come at a cost to your health. Another assumption being made via the successful “slip, slop, slap and wrap” campaigns is that any amount of direct sunlight exposure is bad for you. Can you suffer from a lack of good light?

Obviously, there is a fine line and balance between the harms and benefits of sun exposure as described by the Cancer Council Australia. Energy from the sun is expressed as the visible light spectrum as well as the non visible such as UVA, UVB and infra red light.

This is not only discussed in the context about the benefits and dangers of UV radiation, but the dual action of light is also noted in the debate about the potential benefits and dangers of blue light. Time of day matters!

This is a complex area and it is important to talk to your health care practitioner for specific advice. Light absorption depends on your age, skin colour, metabolism, latitude, the amount of exposure and the time of day.

Shift work has been linked to various health conditions over the years and it does not take much artificial light at night to affect melatonin levels in some individuals (Phillips 2019).

NB: Light therapy and/or natural light exposure is not a replacement for any medical, pharmacological treatment or lifestyle recommendation as directed from your personal physician.

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