LIGHT THERAPY
Can be used any time, including night time.
Can be used indoors, in privacy.
Initial cost and electricity costs
Healthy spectrum of light
Intensity can be varied
No harmful UV light
No vitamin D
Potentially improves energy production
Reduces pain significantly
Does not lead to a sun tan
NATURAL SUNLIGHT
Not always available (weather, night, etc.)
Only available outside
Natural, no cost
Healthy and unhealthy spectrum of light
Intensity cannot be varied
UV light can lead to skin damage etc
Helps vitamin D production
Reduces pain moderately
Leads to a sun tan
Red light therapy is a powerful and versatile tool, but is it better than simply going outside into the sun?
If you live in a cloudy, northern environment without consistent access to the sun, then red light therapy is a no-brainer – red light therapy can make up for the low amount of natural light available. For those that live in tropical or other environments with almost daily access to strong sunlight, the answer is more complicated.
Key differences between sunlight and red light
Sunlight contains a broad spectrum of light, all the way from ultraviolet light to near-infrared.
Contained within the sunlight spectrum are the healthy wavelengths of red and infrared (which enhance energy production) and also UVb light (which stimulates vitamin D production). However there are wavelengths within sunlight that are harmful in excess, such as blue and violet (which reduce energy production and damage eyes) and UVa (which causes sun burn/sun tan and photoaging/cancer). This broad spectrum may be necessary for plant growth, photosynthesis and various effects on pigments in different species, but is not all beneficial for humans and mammals in general. This is the reason why sunblock and SPF sunscreens are necessary in strong sunlight.
Red light is a narrower, isolated spectrum, roughly ranging from 600-700nm – a tiny proportion of sunlight’s. Biologically active infrared ranges from 700-1000nm. So the wavelengths of light that stimulate energy production are between 600 and 1000nm. These specific wavelengths of red and infrared have exclusively beneficial effects with no known side effects or harmful components – making red light therapy a worry free type of therapy compared to sunlight exposure. No SPF creams or protective clothing are required.
Summary
The optimal situation would be to have access to both natural sunlight and some form of red light therapy. Get some sun exposure if you can, then use red light after.
Red light is studied is regards to sunburn and speeding up healing of UV radiation damage. Meaning that red light has a protective effect on the potential harm of sunlight. However, red light alone won’t stimulate vitamin D production in the skin, which you need sunlight for.
Receiving moderate skin exposure to sunlight for vitamin D production, combined with red light therapy in the same day for cellular energy production is perhaps the most protective approach.