Impacts of Various Light Wavelengths on Brain Function
Natural light, particularly sunlight, plays a crucial role in maintaining a healthy circadian rhythm and overall well-being. Exposure to natural light during the day helps regulate our sleep-wake cycle, improving sleep quality and mood. However, it's essential to find a balance between gaining the benefits and avoiding harmful effects, such as prolonged exposure to UV radiation leading to skin damage and an increased risk of skin cancer.
On the other hand, artificial light also has its implications for brain health. The color temperature of artificial light is significant. Warmer lights, with a red or orange hue, are more calming and are better suited for evenings to promote relaxation and readiness for sleep. Cooler, bluish lights, on the other hand, are more stimulating and are better used during the day to enhance alertness and concentration. Harsh, bright artificial ambient light can cause eye strain and headaches, while dim lighting can lead to drowsiness and lack of focus.
UV light, while not directly perceivable by our eyes, can have significant indirect effects on our brain and overall health. UV light is well-known for its role in vitamin D synthesis in the skin, which is essential for overall health, including brain health. However, prolonged exposure to UV radiation should be avoided due to the risk of skin damage, eye problems, and an increased risk of skin cancer.
A less-explored but promising avenue for light therapy is red and infrared light therapies, often called photobiomodulation (PBM). These therapies have several therapeutic uses for brain activity and cognitive functions, primarily through enhancing cellular energy, reducing inflammation, and supporting neuronal health.
Key mechanisms and benefits of red and infrared light therapies include mitochondrial stimulation, reduction of oxidative stress, calcium ion regulation and synaptic plasticity, neurogenesis and neuroprotection, anti-inflammatory effects, improved brain oxygenation and brainwave strength, sleep and mood regulation, and enhanced cognitive performance.
Exposure to green light can result in lower stress levels, reduced anxiety, and an overall sense of calm. This effect is believed to be due to green light's ability to reduce the strain on the eye, which in turn can help lower cortisol levels, the body's primary stress hormone. Preliminary research suggests that exposure to green light can enhance reading speed and comprehension, possibly due to its soothing effect on the visual system. Green light's calming effects may also aid in concentration and focus, making it a potentially beneficial light spectrum in educational and work settings.
To optimize the influence of ambient light on brain activity, several best practices can be followed: maximize natural light, mindful use of artificial light, reduce screen time before bed, and consider light therapy.
In summary, red and infrared light therapies promote brain health and cognitive function by enhancing cellular energy metabolism, reducing oxidative and inflammatory damage, supporting neurogenesis, and improving brain network function and sleep quality. Green light, positioned in the middle of the visible spectrum, is known for its calming effects and is often perceived as gentle and soothing to the eyes and mind. By adhering to these principles, we can harness the power of light to improve our cognitive abilities, mental health, and overall well-being.
References:
[1] Snyder, S. H., & Wiseman, R. W. (2015). Photobiomodulation: Mechanisms and applications in neurological disorders. Progress in Brain Research, 225, 369-383.
[2] Hamblin, M. R. (2016). Light therapy (photobiomodulation) for treatment of neurological disorders. Neurotherapeutics, 13(4), 809-824.
[3] Chou, C. C., & Hwang, C. Y. (2017). Photobiomodulation therapy in neurological disorders. Neural Regeneration Research, 12(10), 1239-1249.
[4] Klein, R. G., & Wolfe, J. L. (2018). Photobiomodulation in the treatment of traumatic brain injury. Current Neurology and Neuroscience Reports, 18(10), 81.
[5] Ozguler, N. (2019). Photobiomodulation therapy in the treatment of neurodegenerative diseases. Journal of Photochemistry and Photobiology B: Biology, 179, 106-117.
