Using the Power of Sunlight for a Healthier You Aetas Protocols

The Science behind Sun Exposure

Exposure to the sun – and therefore ultraviolet (UV) light – is essential for maintaining many aspects of human health. UVB rays convert to a precursor molecule into vitamin D3 which is then transported to the liver and kidneys, where it undergoes further processing to become the active form of vitamin D, regulating calcium and phosphate metabolism and impacting various tissues throughout the body ^{2Holick, M. F. (2007). Vitamin D deficiency. New England Journal of Medicine, 357 (3), 266-281}.

Similarly, photoreceptors in the eyes respond to UV exposure and influence the regulation of our internal body clock. Several studies in the past decade show that insufficient sun exposure can be the reason for an increased incidence of breast cancer, colon cancer, high blood pressure, multiple sclerosis, cardiovascular diseases, Alzheimer’s, autism, asthma, and type 1 diabetes^{3,University of Southampton. (2014, January 17). Here comes the sun to lower your blood pressure. Science Daily.4Alfredsson, L., Armstrong, B. K., Butterfield, D. A., Chowdhury, R., de Gruijl, F. R., Feelisch, M.,Garland, C. F., Hart, P. H., Hoel, D. G., Jacobsen, R., Lindqvist, P. G., Llewellyn, D. J., Tiemeier, H.,Weller, R. B., & Young, A. R. (2020). Insufficient Sun Exposure Has Become a Real Public Health Problem. International journal of environmental research and public health, 17(14), 5014.}.

Studies have also shown that sunlight causes our bodies to produce serotonin and nitric oxide – a chemical that helps protect our cardiovascular system as well as being proven to boost our libido and overall mood^{5Sansone, R. A., & Sansone, L. A. (2013). Sunshine, serotonin, and skin: a partial explanation for seasonal patterns in psychopathology?. Innovations in clinical neuroscience, 10(7-8), 20–24.}.

One of the reasons why light has such a large effect on so many different aspects of our biology is that it can be converted into electrical signals in our brain and body, as well as cascades of biological pathways. In other words, light can actually change how the genes of cells are expressed. It depends on the absorption or reflection of light in a cell, as well as the wavelength of light.

What are wavelengths and how does this matter?

Well, all light has energy, regardless of wavelength. Although we can only see some wavelengths, light affects us at many different levels in the body. It can be direct (on the skin) or indirect (through signals to other organs in the body), but in all cases it starts with how the different wavelengths of light are absorbed. When we are exposed to direct light, we are also hit by short and long wavelengths.

Different wavelengths of light have varying effects on the body^{6Andrew Huberman. (2022, April 18). Using Light (Sunlight, Blue Light & Red Light) to Optimize Health | Huberman Lab Podcast #68}. Long wavelengths, like infrared light, can impact the skin and body by changing how cells and organs function. Red light for example has long wavelengths and can increase blood circulation, alleviate pain^{7Tsagkaris, C., Papazoglou, A. S., Eleftheriades, A., Tsakopoulos, S., Alexiou, A., Găman, M. A., & Moysidis, D. V. (2022). Infrared Radiation in the Management of Musculoskeletal Conditions and Chronic Pain: A Systematic Review. European journal of investigation in health, psychology and education, 12(3), 334–343.}, help with arthritis, and promote sleep by releasing melatonin. In comparison short wavelengths, like UV and blue light, can increase mental performance, affect how alert you are, your concentration, the regulation of hormones and boost your mood by increasing serotonin^{8Alkozei, A., Dailey, N. S., Bajaj, S., Vanuk, J. R., Raikes, A. C., & Killgore, W. D. (2021). Exposure to Blue Wavelength Light Is Associated With Increases in Bidirectional Amygdala-DLPFC Connectivity at Rest. Frontiers in Neurology, 12.}. It can also disrupt sleep cycles, cause eye strain and headaches, and increase the risk of cataracts^{9Wong, N. A., & Bahmani, H. (2022). A review of the current state of research on artificial blue light safety as it applies to digital devices. Heliyon, 8(8), e10282.}.

To minimise the negative effects of blue light from screens, you should reduce your exposure to blue light in the hours around bedtime, and use blue light glasses that filter out blue light if you use screens later in the evening.

Light can also affect our circadian rhythm through melatonin^{10Blume, C., Garbazza, C., & Spitschan, M. (2019). Effects of light on human circadian rhythms, sleep and mood. Somnologie : Schlafforschung und Schlafmedizin = Somnology : sleep research and sleep medicine, 23(3), 147–156.} which is a hormone that your brain produces in response to warm light and darkness. It helps with the timing of your circadian rhythm and your sleep. The hormone works by affecting our sense of wakefulness or fatigue.

When the photoreceptors in your eyes are exposed to blue light, they signal to your brain to stop releasing melatonin, which makes you wake up. On the other hand, red light signals the brain to begin releasing melatonin. The less blue light there is around you, the greater the amount of melatonin released, and the more tired you become.

On short days (in winter months), the duration of melatonin release will be much longer, and on long days (in summer months), it will be shorter. This is why it is important to have a consistent sleep schedule, as it helps regulate the production of melatonin and your sleep-wake cycle.

Benefits behind Sun Exposure

1. Boosts Vitamin D Production

Sunlight is the most natural and abundant source of vitamin D. Vitamin D is essential for our health and helps our body absorb calcium, strengthen our bones, and support our immune system. It even reduces the risk of certain diseases like osteoporosis, heart disease, and some types of cancer.

A lack of vitamin D can cause soft bones, bone fractures, infections, heart disease, diabetes, cancer, and other degenerative diseases. We get vitamin D from sunlight, so not getting enough sun or outdoor activity can lead to a deficiency. This is common in countries with little sun exposure, like Denmark. Even people who spend a lot of time outside might not get enough vitamin D. It can be helpful to measure your vitamin D levels via a blood test and take supplements. Vitamin D supplements can improve immune defence, bone health, and well-being.

The official recommended daily dose of vitamin D is 400-800 IU/day, but that might not be enough for many adults, especially in northern countries^{11Pfiffner, M. M. S. & Examine.com. (2022, September 28). Vitamin D.}. Aetas recommends 2,500 IU per day for people that live in the Northern Hemisphere.

2. Enhances Mood and Fights Depression

Ever noticed how spending time outdoors on a sunny day instantly uplifts your spirits? Sunlight has a profound effect on our mood and mental well-being. Exposure to sunlight stimulates the production of serotonin, a neurotransmitter known as the “happy hormone,” which helps regulate mood, sleep patterns, and appetite^{12Alfredsson, L., Armstrong, B. K., Butterfield, D. A., Chowdhury, R., de Gruijl, F. R., Feelisch, M., Garland, C. F., Hart, P. H., Hoel, D. G., Jacobsen, R., Lindqvist, P. G., Llewellyn, D. J., Tiemeier, H., Weller, R. B., & Young, A. R. (2020). Insufficient Sun Exposure Has Become a Real Public Health Problem. International journal of environmental research and public health, 17(14), 5014.}. Adequate sunlight has been linked to alleviating symptoms of depression, reducing stress, and boosting overall mental health.

3. Improves Sleep Patterns

The natural exposure to sunlight during the day helps regulate our internal body clock, known as the circadian rhythm. This synchronisation is crucial for maintaining healthy sleep patterns. Exposure to sunlight in the morning or early afternoon helps signal to our bodies that its daytime, thus promoting alertness and wakefulness. A well-regulated circadian rhythm enhances the quality and duration of our sleep, leading to improved cognitive function, increased productivity, and a better overall sense of well-being. To read more on how to improve your sleep check out our article here.

4. Strengthens the Immune System

Sunlight exposure has been found to have a positive impact on our immune system. Research suggests that moderate sun exposure can enhance the function of white blood cells, which play a crucial role in defending our bodies against infections and diseases. Additionally, vitamin D produced by sunlight stimulates the production of antimicrobial peptides, which possess antimicrobial properties and aid in fighting off pathogens^{13González Maglio, D. H., Paz, M. L., & Leoni, J. (2016). Sunlight Effects on Immune System: Is There Something Else in addition to UV-Induced Immunosuppression?. BioMed research international, 2016, 1934518.}.

5. Supports Skin Health

While excessive sun exposure can damage the skin, moderate and responsible exposure to sunlight can actually benefit its health. Sunlight helps stimulate the production of melanin, the pigment responsible for giving our skin its colour and protecting it from harmful UV rays. Additionally, sunlight has been associated with improvements in skin conditions such as psoriasis, eczema, and acne^{5Sansone, R. A., & Sansone, L. A. (2013). Sunshine, serotonin, and skin: a partial explanation for seasonal patterns in psychopathology?. Innovations in clinical neuroscience, 10(7-8), 20–24.}. However, it’s important to strike a balance and always take appropriate sun protection measures to avoid sunburn and long-term damage.