Fear of skin cancer leads a lot of people to hide inside. And if they venture out, use sunscreen, clothing, gloves, hats and sunglasses to “protect” themselves. The official story is that ultraviolet light, in particular UVB light, causes the deadly form of skin cancer, aka melanoma. Before we unpack this story, let’s look at some numbers:

• • Overall number of deaths in the US in 2023 is expected to be around 3.4 million
  • 8000 people are expected to die from melanoma in the US in 2023; that is 0.02% of all deaths
  • The risk for all leading causes of death (except accidents/injury) are lowered by sunlight exposure

So even if the sun can cause melanoma, the proposed risk/benefit ratio does not make any sense. Even the WHO shared in a 2006 report that the risk/benefit ratio of UV avoidance is 60:1. They obviously did not state this publicly, but compare the numbers in the report on pages 76 and 78, and you can see it for yourself. Do you really want to gamble with your health when the odds are that bad? And that is only a small part of the story. In other words…

If the sun causes skin cancer, than spoons do make people fat.

– Dr Leland Stillman

Here are some key facts

• • UVB light does not increase skin cancer risk [1]
  • UVB light significantly decreases the risk for cardiovascular and cerebrovascular events (heart disease, blood clots, stroke etc) [2]
  • indoor workers get 3-9 times less solar ultraviolet light exposure than outdoor workers, yet only indoor workers show increasing rates of melanoma [3]

How is this possible? Well, being inside stops any UVB from reaching you, but you still get UVA through glass. Further, red and infrared light are pretty much absent indoors (not part of LED/fluorescent lighting and largely blocked by windows). And you are bathing in excessive blue light all day/night.

• • blue light triggers apoptosis and some of its effects are similar to those of ultraviolet radiation [4]
  • blue light induces oxidative stress in human skin [5]
  • blue light disrupts circadian clocks and causes inflammation and DNA damage in the skin [6]
  • red light curtails melanoma by preventing tumor growth and improving immune response [7]
  • infrared light protects skin cells against damage [8] and promotes healing and repair [9]

Blue and red light in the sun are like predator and prey…they each perfectly balance one another. But modern artificial light has 4x the amount of blue and no red. This destroys the coupled cycle.

– Dr Jack Kruse

The natural light spectrum is balanced and complementary. UVB and UVA light are yoked. UV is balanced by infrared, and blue is balanced by red. All of these relationships are broken when you live under artificial light. Then there are other factors that can drive (skin) cancer that no one is talking about. Here are just two examples: stress [10] and shift work [11] significantly increase your skin cancer risk!

What happens when you break the balance?

Above is a famous image of a truck driver with severe skin damage from 28 years of being on the road, with his left side having faced the window. Is it sun damage? Yes, but the damage is driven by behaviour and a completely altered light spectrum.

1. 1. 8-10hrs every day inside aka hardly any time outside
   2. UVB: no
   3. UVA: yes
   4. blue: yes
   5. red: hardly
   6. infrared: hardly
   7. possible shift work
   8. other lifestyle factors unknown

In other words, the light spectrum he lived under was mainly composed of short-wavelength stressors and deprived of long-wavelength repair. Do not make the same mistake and then blame the sun.

Be smart and behave accordingly

Make sure to read the chapter on smart sun exposure in the learn section of the Circadian app. The short of it is:

1. 1. Get natural light in your eyes and on your skin every morning
   2. Expose your skin to the sun every day for brief periods (focus on morning and late afternoon exposure first, middle of the day second)
   3. Gradually increase your exposure over time
   4. Make sure not to burn

All living beings are adapted to sunlight. If sunlight does not promote health, but harms it, the reason is that we handle sunlight incorrectly

– Dr Alexander Wunsch

Keep in mind that intermittent sun exposure (aka hitting the beach on the weekend while spending all day in an office during the week) increases melanoma risk, while consistent sun exposure decreases it [12]. And remember that you need the natural composition found in sunlight, not some altered spectrum. 

Mind your rhythm, mind your light ☀️

References

[1] Y.‐H. Wu and others, Risk of skin cancer after ultraviolet phototherapy in patients with vitiligo: a systematic review and meta‐analysis, Clinical and Experimental Dermatology, Volume 47, Issue 4, 1 April 2022, Pages 692–699, https://doi.org/10.1111/ced.15010

[2] Bae, J M et al. “Both cardiovascular and cerebrovascular events are decreased following long-term narrowband ultraviolet B phototherapy in patients with vitiligo: a propensity score matching analysis.” Journal of the European Academy of Dermatology and Venereology : JEADV vol. 35,1 (2021): 222-229. doi:10.1111/jdv.16830

[3] Godar, Dianne E et al. “Increased UVA exposures and decreased cutaneous Vitamin D(3) levels may be responsible for the increasing incidence of melanoma.” Medical hypotheses vol. 72,4 (2009): 434-43. doi:10.1016/j.mehy.2008.09.056

[4] Nishio, Takashi et al. “Blue light exposure enhances oxidative stress, causes DNA damage, and induces apoptosis signaling in B16F1 melanoma cells.” Mutation research. Genetic toxicology and environmental mutagenesis vol. 883-884 (2022): 503562. doi:10.1016/j.mrgentox.2022.503562

[5] Nakashima, Yuya et al. “Blue light-induced oxidative stress in live skin.” Free radical biology & medicine vol. 108 (2017): 300-310. doi:10.1016/j.freeradbiomed.2017.03.010

[6] Dong, K et al. “Blue light disrupts the circadian rhythm and create damage in skin cells.” International journal of cosmetic science vol. 41,6 (2019): 558-562. doi:10.1111/ics.12572

[7] Austin, Evan et al. “Red Light Phototherapy Using Light-Emitting Diodes Inhibits Melanoma Proliferation and Alters Tumor Microenvironments.” Frontiers in oncology vol. 12 928484. 24 Jun. 2022, doi:10.3389/fonc.2022.928484

[8] Menezes, S et al. “Non-coherent near-infrared radiation protects normal human dermal fibroblasts from solar ultraviolet toxicity.” The Journal of investigative dermatology vol. 111,4 (1998): 629-33. doi:10.1046/j.1523-1747.1998.00338.x

[9] Avci, Pinar et al. “Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring.” Seminars in cutaneous medicine and surgery vol. 32,1 (2013): 41-52. PMCID: 4126803

[10] E. de Vries and others, Known and potential new risk factors for skin cancer in European populations: a multicentre case–control study, British Journal of Dermatology, Volume 167, Issue s2, 1 August 2012, Pages 1–13, https://doi.org/10.1111/j.1365-2133.2012.11081.x

[11] Yousef, Einas et al. “Shift work and risk of skin cancer: A systematic review and meta-analysis.” Scientific reports vol. 10,1 2012. 6 Feb. 2020, doi:10.1038/s41598-020-59035-x

[12] Elwood, J M, and J Jopson. “Melanoma and sun exposure: an overview of published studies.” International journal of cancer vol. 73,2 (1997): 198-203. doi:10.1002/(sici)1097-0215(19971009)73:2<198::aid-ijc6>3.0.co;2-r