Lack of Photo Adaptation of the Skin to Sun Exposure
Updated: May 2, 2022
Although denied by dermatologists and most of the medical establishment, a tan provides very good protection against sunburn. Melanoma, to the extent it is related at all to sun exposure (some melanomas have nothing to do with sun exposure), is related only to severe sunburns, and a good tan provides protection against sunburns. Reducing your risk of sun-related melanoma requires avoidance of severe sunburns, so having a good tan reduces your risk of melanoma. Unlike chemical sunscreens, a tan is not subject to washing off, incorrect application or failure to reapply.
Some medical authorities deny that a tan provides any protection against sunburn at all, while others say it provides protection in the range of 2-3 times (SPF of 2-3). Amazingly, no scientific study on the protection afforded by tan has ever been published in the entire history of the world. The probable reason for this is that, given the medical establishment’s longstanding and incorrect exaggerations of the harms of sun exposure, it is considered unethical to do a scientific study that involves intentionally exposing a human being to the sun or a sunlamp.
However, these ethical considerations do not apply to exposing yourself to the sun or a sunlamp, so an individual could theoretically do such a study on themselves. Allen Miller, the President of the Sunshine Health Foundation, did such a study on himself in the summer and early fall of 2021. The result showed that his tan had an SPF of 24.
Click below to download the official report of his experiment.
Risks of Sun Exposure
In obtaining the sun exposure you need for good health, it is important to keep in mind the risks of sun exposure and take precautions to minimize them. The risks associated with sun exposure are skin cancer, eye damage and skin ageing.
Skin Cancer. There are three types of skin cancer: melanoma, squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). Of the three, melanoma is by far the most serious.
Melanoma. The relationship between sun exposure and melanoma is unusual. Severe sunburns causing pain lasting 48 hours, blistering or peeling increase the risk of melanoma, but nonburning sun exposure even in very large amounts reduces or has a null effect on the risk of melanoma. Five severe sunburns per decade of life compared to no severe sunburns increase the risk of melanoma by 224% (Dennis et al., Annals of Epidemiology 2008; 18:614-627. http://doi.org/10.1016/j.annepidem.2008.04.006).
Many severe sunburns compared to few severe sunburns increase the risk of melanoma by 83% (Caini et al., European Journal of Cancer 2009; 45:3054-3063. Http://doi. org/10.1016/j.ejca.2009.05.009), Highest quartile of nonburning sun exposure compared to lowest quartile reduces the risk of melanoma by 22% (Vuong et al., International Journal of Cancer 2014; 134:2735-2741.; http://doi.org/ 10.1002/ijc.28603). Nonburning sun exposure in childhood reduces the lifetime risk of melanoma (Kaskel et al., British Journal of Dermatology 2001; 145:602-609. https://doi.org/10.1046/j.1365-2133.2001.04432.x). High occupational sun exposure compared to low reduces the risk of melanoma by 14% (Armstrong et al., Journal of Photochemistry and Photobiology 2001; 63:8-18. http://doi.org/10.1016/s1011-1344(01)00198-1). Other studies have found that outdoor workers have lower risk of melanoma than indoor workers. Pukkala et al., Acta Oncologica 2009; 48:646-790. http://doi.org/10.1080/02841860902913546.
Consistent with these findings, the eminent melanoma cellular physicist/biologist Dr. F.R. de Gruijl of Leyden University in The Netherlands discovered in 2005 that melanocytes, unlike most other cells in the body, are not replicating cells, and severe sunburn or other trauma is required to stimulate their replication (van Schanke et al., Journal of Investigative Dermatology 2005; 124:241-247; https://doi.org/10.1111/j.0022-202X.2004.23551.x ). It is only when cells divide and replicate that cancer can occur. Dr. A.C White of Cornell University confirmed Dr. de Gruijl’s discovery in 2017 (Moon et al., Cell Stem Cell 2017; 21:665-678; http://doi.org/10.1016/j.stem.2017.09.001).
It should be noted that some types of melanoma have nothing to do with sun exposure. These melanomas occur on the palms of the hands, the soles of the feet, or under the nails. The most common place is under the nail of the big toe. The famous musician Bob Marley died from melanoma under the nail of his big toe.
SCC. Severe sunburns also increase the risk of SCC. Six to ten severe sunburns in childhood increase the lifetime risk of SCC by 132% (de Vries et al., British Journal of Dermatology 2012; 167:Suppl 2:1-13. http://doi.org/10.1111/j.1365-2133.2012.11081.x. 167); severe sunburn at any age increases the risk of melanoma by 23% (Armstrong et al., Journal of Photochemistry and Photobiology 2001; 63:8-18. http://doi.org/10.1016/s1011-1344(01)00198-1). In contrast to melanoma, however, nonburning sun exposure increases the risk of SCC. However, the amounts of cumulative sun exposure needed to increase the risk for SCC are very large indeed: 20,000 hours for persons with light skins like residents of The Netherlands and 70,000 hours for persons with darker skins like residents of southern Europe (Kennedy et al, Journal of Investigative Dermatology 2003; 120:1087-1093. http://doi.org/ 10.1046/j.1523-1747.2003.12246.x). Since almost all sun-related SCCs occur on the face and neck, persons who expect to have a large amount of sun exposure in their lifetimes can cover their faces with a white towel when sunbathing to get the sun exposure they need for good health.
BCC. Severe sunburns also increase the risk of BCC. More than three lifetime severe sunburns compared to none increase the risk of BCC by 142% (Rosso et al., Tumori 1999; 85:435-442. https://doi.org/10.1177%2F030089169908500603); six to ten severe sunburns in childhood increase the lifetime risk of BCC by 133% (Rosso et al., British Journal of Cancer 1996; 73:1447-1454. http://doi.org/ 10.1038/bjc.1996.275); severe sunburn at any age increases the risk of BCC by 40% (Armstrong et al., Journal of Photochemistry and Photobiology 2001; 63:8-18. http://doi.org/10.1016/s1011-1344(01)00198-1). Nonburning sun exposure in large amounts increases the risk of BCC, more than 20,000 lifetime hours for light-skinned persons (Kennedy et al, Journal of Investigative Dermatology 2003; 120:1087-1093. http://doi.org/ 10.1046/j.1523-1747.2003.12246.x) and more than 8,000 lifetime hours for darker-skinned persons with a decrease in risk at 200,000 lifetime hours (Rosso et al., British Journal of Cancer 1996; 73:1447-1454. http://doi.org/ 10.1038/bjc.1996.275). Most BCCs also occur on the face and neck, so persons can protect themselves from BCC risk by covering their faces when sunbathing.
Eye Damage. This principal risk of sun exposure regarding the eyes is cataracts (Lucas et al., Photochemical and Photobiological Sciences 2019; 18:641-680. https://doi.org/10.1039/C8PP90060D). This risk can be mitigated by wearing sunglasses or keeping eyes closed when sunbathing.
Skin Ageing. Skin Ageing risk from the sun occurs mostly on the face, so this risk can be mitigated by covering the face when sunbathing.