Several years ago, I did a 2-part blog on the dangers of sunscreens. They have some good information, and the links are below.
The Dangers of Commercial Sunscreens, Part 1 https://www.donnieyance.com/the-dangers-of-commercial-sunscreens/
The Dangers of Commercial Sunscreens, Part 2 https://www.donnieyance.com/the-dangers-of-commercial-sunscreens-part-2/
Skin cancer is the most commonly diagnosed cancer in the US. Despite decades of widespread use of sunscreen and sunblock, the rates of the three main types of skin cancer—basal cell carcinoma, squamous cell carcinoma, and melanoma—are on the rise.[1]This concerning trend raises questions about the effectiveness of current sun protection methods and the factors contributing to skin cancer.
The concept of topical photoprotective products dates back to ancient Egypt in 4000 BC, but commercial sunscreens only became available in the 1920s–1930s.[2]Various methods exist to shield the skin from harmful UV radiation. The most common approach is to apply sunscreen products containing UV-absorbing or reflecting active molecules.[3] The US Food and Drug Administration (FDA) regulates sunscreens as over-the-counter drugs.[4]
Sunscreens can be chemical (organic UV absorbers) or physical (inorganic UV absorbers). Important considerations include the sunscreen’s formulation, stability when exposed to light, preservatives, and potential for skin reactions. The skin’s epidermis predominantly absorbs UVB radiation. At the same time, UVA penetrates deeper into the dermis and significantly contributes to photoaging (Photoaging is the premature aging of skin caused by prolonged exposure to ultraviolet (UV) radiation from the sun or artificial sources like tanning beds or sun lamps ).[5]
However, recent evidence suggests that visible and infrared light may play a role in photoaging and should be considered when choosing sunscreen.
- Visible light has a wavelength range of 390–750 nanometers (nm) and is what humans can see with their eyes.
- Infrared (IR) has a wavelength range of 750 nanometers to 1 millimeter (mm), which is longer than visible light but shorter than microwaves. IR is invisible to the human eye, but humans can feel it as heat. As an object’s temperature increases, it radiates more IR energy.
Currently, many US FDA-approved filters provide protection against long UVA (> 370 nm) but none against visible light.[6]
The Controversy Surrounding Sunscreen and Skin Cancer
Many chemical sunscreens contain benzophenone as an active ingredient. This ingredient is known for generating free radicals when exposed to UV light, which can potentially lead to melanoma and other skin cancers, raising concerns about the safety of protective products. This initiates a chain reaction that could ultimately lead to melanoma and other skin cancers.
A recent study published in the Journal of the American Medical Association found elevated levels of four sunscreen ingredients in blood samples, prompting concerns about their systemic absorption and long-term health effects.[7]
As more and more people use sunscreen, rates of melanoma and other skin cancers are going up.
The statistics on all types of skin cancer do not support the use of sunscreens and sunblocks demonstrating any protection whatsoever from skin cancer and may increase the risk:
- Melanoma cases were diagnosed annually from 1982-2019.[8]
Data from AIHW Cancer Data in Australia 2023 web report and supplementary data tables.
- According to one estimate, about 5.4 million basal and squamous cell skin cancers are diagnosed each year in the US (occurring in about 3.3 million people, as some people have more than one).[9]
- Increasing incidence rates of BCC have been reported worldwide for decades. The prognosis for Europe is an increasing incidence rate of 5.5 % per year.[10]
- Even cases of Merkel cell carcinoma (MCC), a rare and aggressive skin cancer that caused the recent death of singer Jimmy Buffet, are projected to jump to over 3,200 cases per year over the next two years.[11] From 2000-2013, the number of reported solid cancer cases increased by 15%, melanoma cases increased by 57%, and MCC cases increased by 95%. In 2013, the MCC incidence rate was 0.7 cases/100,000 person-years in the U.S., corresponding to 2488 cases/year. MCC incidence increased exponentially with age, from 0.1 to 1.0 to 9.8 (per 100,000 person-years) among age groups 40-44 years, 60-64 years, and ≥85 years, respectively. Due to the aging of the Baby Boomer generation, US MCC incident cases are predicted to climb to 2835 cases/year in 2020 and 3284 cases/year in 2025.[12]
Despite being a cornerstone of skin cancer prevention campaigns, the efficacy of sunscreen has been called into question. A comprehensive review and meta-analysis of epidemiological studies found no significant association between sunscreen use and skin cancer risk in the general population.[13] The cumulative evidence before the 1980s showed a relatively strong positive association between melanoma and sunscreen use. This study did not find the expected protective benefits of sunscreen against skin cancer in the general population.
The Relationship Between Sunscreen and Melanoma
Studies examining the link between sunscreen use and melanoma—a highly aggressive form of skin cancer—have produced conflicting results. A recent meta-analysis of 28 studies spanning from 1979 to 2018 found varying conclusions regarding the protective benefits of sunscreen.[14]
The study included 21,069 melanoma cases from 28 studies published 1979-2018: 23 case-control (11 hospital-based, 12 population-based), one ecological, 3 cohort, and one randomized controlled trial.
The figure shows the forest plot for melanoma risk comparing ever‐ vs. never‐use of sunscreen for all studies that reported a minimally adjusted estimate stratified by study design.
Potential Risks of Sunscreen
One potential reason why sunscreen might increase the risk of skin cancer is that heavy use of sunscreen encourages excessive exposure to the sun and may increase the risk of skin cancer.
Another is the emerging evidence that suggests that some chemical sunscreen ingredients are systemically absorbed.[15]
In the USA, most broad-spectrum sunscreens protect against ultraviolet B (UVB) radiation and short-wavelength ultraviolet A (UVA) radiation. Evidence suggests that visible and infrared light may play a role in photoaging and should be considered when choosing sunscreen.[16]
Environmental Impact
The environmental impact of sunscreen use is also a growing concern. Certain chemicals in sunscreens, particularly those in aerosolized products, can contribute to air pollution and harm marine ecosystems, including coral reefs.
Many pristine waters worldwide now post signs that people should not use sunscreens or wash off before entering the water. Even the little bit of sunscreen that ends up in the lagoons and lakes impacts the life of the fish and vegetation. in a review looking at all 32 published studies until June 2020, 14 different organic UV filters in seawater near coral reefs were detected in the nanograms per liter range, in contrast to toxic levels in the micrograms per liter to milligrams per liter range reported in nine papers. This puts the toxic levels of organic UV filters at 1000- to 1 million-fold higher concentrations than currently reported.[17]
The National Oceanic and Atmospheric Administration identified ten sunscreen ingredients as toxic to coral and marine life: oxybenzone, benzophenone-1, benzophenone-8, PABA, methyl benzylidene camphor, 3-benzylidene camphor, nano-titanium dioxide, nano-zinc oxide, octinoxate, and octocrylene.[18]
Aerosolized sunscreens are the worst; often, more end up in the atmosphere, and they are also highly flammable. Many people develop rashes from the chemicals; the most commonly implicated allergenic ingredients are octocrylene, oxybenzone, and octyl methoxycinnamate.[19]
Sun exposure carries both harms and benefits. One of the most well-established benefits of exposure to ultraviolet (UV) radiation is vitamin D production. Australia has the highest incidence of skin cancer in the world, but despite the high ambient UV radiation, approximately one-quarter of the population is estimated to be vitamin D deficient. Balancing the risks and benefits is challenging and requires effective communication.[20] Enter hormesis – gradually slow exposure, allowing your skin to build a tan and not burn naturally, is the safest and most natural way to adapt to the sun.
Less sun exposure is equally as harmful. Too much sun exposure can and will damage the skin, while too little sun is associated with numerous diseases and vitamin D deficiency. Sun exposure in moderate amounts triggers hormesis. When you get the correct dose of UV rays, sun exposure is incredibly healing and vital for optimal health.
Mechanisms of UVB-induced skin aging. Summary of the main pathways affected by chronic exposure to UVB and their impact on the appearance of the tissue.[21]
Sunlight in the correct dose makes your cells more robust. It can even protect you from cancer – “Sunlight may reduce the risk of non-Hodgkin lymphoma (NHL) and may be associated with increased survival rates in patients with early-stage melanoma. In a large population-based case-control study of more than 3700 patients with incident lymphoma and nearly 3200 control subjects in Sweden and Denmark, Smedby et al. reported a 20% to 40% reduction in the risk of this cancer. The risk reduction was dose-related with increasing indices of prior sun exposure.”[22]
You need a specific amount of sunlight, depending on how much melanin you have in your skin.[23] The darker the skin, the more sunlight you need for vitamin D absorption and overall health.[24] Common sense tells us people should stay in the sun for half as long as it takes their particular skin type to burn before covering up and retiring to the shade.
If you are searching for a clean, organic sunscreen, find one that only uses titanium dioxide and zinc oxide as active ingredients. Although too much zinc oxide will leave your skin white, it is the safest and best natural sunscreen.
I have never used sunscreen but am primarily of southern European and Italian descent. Some good brands of sunscreens do not contain any harsh chemicals, but I recommend gradual exposure to the sun and allowing your body to build up a tan, which provides natural protection. I also recommend skin care products that contain herbal and nutritional compounds that have been shown to protect the skin from sun damage, skin cancer, and aging. I only use “SKIN-PROTECT,” made at the Mederi Center, on my skin. Skin Protect supports the body’s innate ability to adapt to the sun and mitigate oxidative and inflammatory aspects caused by sun exposure.
Skin protective herbs and herbal compounds include for topical and internal use:
Sea Buckthorn Oil has been shown to prevent UV-induced skin damage. It is one of the richest and most diverse sources of carotenoids. Carotenoids are important for human health as they are present in high concentrations in the human retina, where they work as antioxidants that protect human eyes from damage caused by sunlight.[25]
Several years ago, I did a blog on Sea Buckthorn entitled, “The Unique Health Benefits of Siberian Sea Buckthorn Oil”
Green tea (Centella Asiatica) Extract is moisturizing and anti-inflammatory and has redox/anti-oxidant effects on the skin.[26]
Milk thistle seed (Silybum marianum) extract protects against skin cancer: anti-inflammatory, antioxidant, and immunomodulatory effects.[27]
Topical botanical redox/antioxidants polyphenols and carotenoids are emerging as potential topical and non-topical photoprotection agents.
[28] A Diagram of Skin Cancer
Many botanical compounds, known as natural biologic compounds (NBC), provide network interactions based on their known activity towards many biomarkers and pathways in the skin. They reveal the capacity to inhibit both bystander signaling and cell cycle/DNA damage molecules while increasing the expression of various redox/antioxidant enzymes.
This is a schematic of the proposed capacities of the NBC in the context of protection against UVR-induced DNA damage in the skin. UVB and UVA affect the DNA either directly to induce a range of photo products or indirectly through non-DNA chromophores and ROS, leading to DNA oxidization.[29]
Many botanical compounds are secondary metabolites that can modulate redox signaling and protect against oxidative damage. They are abundantly found in plant tissue, where they play an essential role in the defense system and tolerance to a range of environmental stresses that can lead to excessive production of free radicals. Plant polyphenols inhibit inflammatory and metabolic responses to solar-simulated UV irradiation in normal primary human epidermal keratinocytes.[30]
For example, polyphenols from green tea (Camellia sinensis) extract compounded with the polyphenol resveratrol provided SPF protection independent of physical and chemical UV filters. Still, additional in vivo studies must be performed to assess its effectiveness fully.[31] Resveratrol enhances the skin protective and anti-skin cancer effects of ursolic acid in sage and basil.[32] The anti-photoaging effects of tea from green tea have been proven in many studies.[33]
Niacinamide (Nicotinamide) is the active amide form of niacin (vitamin B3). Unlike niacin, niacinamide does not cause cutaneous flushing. Early studies have shown that nicotinamide enhances DNA repair and decreases the formation of cyclobutene pyrimidine dimers in human keratocytes.[34] In one phase III RCT, which has not been replicated, nicotinamide 500 mg twice daily was associated with a decreased rate of development of both actinic keratoses and nonmelanoma skin cancers over 12 months.[35]
Other suggestions for protecting the skin include wide-brimmed hats, eye protection (e.g., “wrap-around” sunglasses with ultraviolet radiation protection), and seeking shade when the ultraviolet index is above 3 (usually 11 am–3 pm, April to September in Canada). Typically, thicker clothing with tighter weave fabrics and darker colors offers greater protection.[36],[37]
About the Author:
Donald R. Yance is the founder of the Mederi Center. A Clinical Master Herbalist and Certified Nutritionist, Donnie is renowned for his extraordinary knowledge and deep understanding of the healing properties of plants and nutrition, as well as of epigenetics, laboratory medicine, oncologic pathology, and molecular oncology. He is a professional member of the American Herbalists Guild, National Association of Nutrition Professionals, Academy of Integrative Health and Medicine, and the Society for Integrative Oncology.
[1] Davis, Kyleen E. MSN, FNP-BC, DCNP, Skin Cancer Rates Rising, Journal of the Dermatology Nurses’ Association 12(3):p 113-114, 5/6 2020. | DOI: 10.1097/JDN.0000000000000543
[2] Guan LL, Lim HW, Mohammad TF. Sunscreens and Photoaging: A Review of Current Literature. Am J Clin Dermatol. 2021 Nov;22(6):819-828. doi: 10.1007/s40257-021-00632-5. Epub 2021 Aug 13. PMID: 34387824; PMCID: PMC8361399.
[3] Saewan N, Jimtaisong A. Natural products as photoprotection. J Cosmet Dermatol. 2015 Mar;14(1):47-63. doi: 10.1111/jocd.12123. Epub 2015 Jan 12. PMID: 25582033.
[4] Over-the-Counter Monograph M020: Sunscreen Drug Products for Over-the-Counter Human Use (Posted September 24, 2021), https://dps-admin.fda.gov/omuf/omuf/sites/omuf/files/primary-documents/2022-09/Final%20Administrative%20Order%20OTC000006_M020-Sunscreen%20Drug%20Products%20for%20OTC%20Human%20Use.pdf
[5] Battie C, Jitsukawa S, Bernerd F, Bino SD, Marionnet C, Verschoore M. New insights in photoaging, UVA induced damage and skin types. Exp Dermatol. 2014;23:7–12. doi: 10.1111/exd.12388.
[6] Guan LL, Lim HW, Mohammad TF. Sunscreens and Photoaging: A Review of Current Literature. Am J Clin Dermatol. 2021 Nov;22(6):819-828. doi: 10.1007/s40257-021-00632-5. Epub 2021 Aug 13. PMID: 34387824; PMCID: PMC8361399.
[7] Matta MK, Zusterzeel R, Pilli NR, et al. Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial. JAMA. 2019;321(21):2082–2091. doi:10.1001/jama.2019.5586
[8] https://www.canceraustralia.gov.au/cancer-types/melanoma/statistics
[9] https://www.cancer.org/cancer/types/basal-and-squamous-cell-skin-cancer/about/key-statistics.html
[10] Seidl-Philipp M, Frischhut N, Höllweger N, Schmuth M, Nguyen VA. Known and new facts on basal cell carcinoma. J Dtsch Dermatol Ges. 2021 Jul;19(7):1021-1041. doi: 10.1111/ddg.14580. PMID: 34288482; PMCID: PMC8361778.
[11] https://www.health.harvard.edu/blog/rare-and-often-aggressive-merkel-cell-cancer-is-best-caught-early-202310162982
[12] Paulson KG, Park SY, Vandeven NA, Lachance K, Thomas H, Chapuis AG, Harms KL, Thompson JA, Bhatia S, Stang A, Nghiem P. Merkel cell carcinoma: Current US incidence and projected increases based on changing demographics. J Am Acad Dermatol. 2018 Mar;78(3):457-463.e2. doi: 10.1016/j.jaad.2017.10.028. Epub 2017 Nov 2. PMID: 29102486; PMCID: PMC5815902.
[13] Silva ESD, Tavares R, Paulitsch FDS, Zhang L. Use of sunscreen and risk of melanoma and non-melanoma skin cancer: a systematic review and meta-analysis. Eur J Dermatol. 2018 Apr 1;28(2):186-201. doi: 10.1684/ejd.2018.3251. PMID: 29620003.
[14] Caroline G. Watts, MPH, PhD; Martin Drummond, MBiost; Chris Goumas, MPH; et al , Sunscreen Use and Melanoma Risk Among Young Australian Adults, JAMA Dermatol. Published online July 18, 2018. doi:10.1001/jamadermatol.2018.1774.
[15] Sander M, Sander M, Burbidge T, Beecker J. The efficacy and safety of sunscreen use for the prevention of skin cancer. CMAJ. 2020 Dec 14;192(50):E1802-E1808. doi: 10.1503/cmaj.201085. PMID: 33318091; PMCID: PMC7759112.
[16] Guan LL, Lim HW, Mohammad TF. Sunscreens and Photoaging: A Review of Current Literature. Am J Clin Dermatol. 2021 Nov;22(6):819-828. doi: 10.1007/s40257-021-00632-5. Epub 2021 Aug 13. PMID: 34387824; PMCID: PMC8361399.
[17] Mitchelmore CL, Burns EE, Conway A, Heyes A, Davies IA. A critical review of organic ultraviolet flter exposure, hazard, and risk to corals. Environ Toxicol Chem. 2021;40:967–88.
[18] US Department of Commerce NO and AA. Sunscreen chemicals and marine life [Internet]. [cited 2021 Mar 27]. Available from: https://oceanservice.noaa.gov/news/sunscreen-corals.html.
[19] Rodríguez E, Valbuena MC, Rey M, et al. Causal agents of photoallergic contact dermatitis diagnosed in the national institute of dermatology of Colombia. Photodermatol Photoimmunol Photomed 2006;22:189–92.
[20] Tran V, Janda M, Lucas RM, McLeod DSA, Thompson BS, Waterhouse M, Whiteman DC, Neale RE. Vitamin D and Sun Exposure: A Community Survey in Australia. Curr Oncol. 2023 Feb 18;30(2):2465-2481. doi: 10.3390/curroncol30020188. PMID: 36826149; PMCID: PMC9955356.
[21] Cavinato M, Waltenberger B, Baraldo G, Grade CVC, Stuppner H, Jansen-Dürr P. Plant extracts and natural compounds used against UVB-induced photoaging. Biogerontology. 2017 Aug;18(4):499-516. doi: 10.1007/s10522-017-9715-7. Epub 2017 Jul 12. PMID: 28702744; PMCID: PMC5514221.
[22] Kathleen M. Egan and others, Sunlight and Reduced Risk of Cancer: Is The Real Story Vitamin D?, JNCI: Journal of the National Cancer Institute, Volume 97, Issue 3, 2 February 2005, Pages 161–163, https://doi.org/10.1093/jnci/dji047
[23] Brenner, M., & Hearing, V. J. (2008). The protective role of melanin against UV damage in human skin. Photochemistry and photobiology, 84(3), 539–549. https://doi.org/10.1111/j.1751-1097.2007.00226.x
[24] Harris, S. S. (2006). Vitamin D and African Americans. The Journal of Nutrition, 136(4), 1126-1129. https://doi.org/10.1093/jn/136.4.1126
[25] Pongcharoen S, Warnnissorn P, Leŗtkajornsin O, et al. Protective effect of silk lutein on ultraviolet B-irradiated human keratinocytes. Biol Res. 2013;46(1):39–45. doi: 10.4067/S0716-97602013000100006.
[26] A. Ratz-Łyko, J. Arct, K. Pytkowska Moisturizing and Antiinflammatory Properties of Cosmetic Formulations Containing Centella asiatica Extract, Indian J Pharm Sci. 2016 Jan-Feb; 78(1): 27–33.
[27] Katiyar SK. Silymarin and skin cancer prevention: anti-inflammatory, antioxidant and immunomodulatory effects (Review). Int J Oncol. 2005 Jan;26(1):169-76. PMID: 15586237.
[28] Gupta S, Mukhtar H. Chemoprevention of skin cancer through natural agents. Skin Pharmacol Appl Skin Physiol. 2001 Nov-Dec;14(6):373-85. doi: 10.1159/000056371. PMID: 11598437.
[29] Markiewicz E, Idowu OC. DNA damage in human skin and the capacities of natural compounds to modulate the bystander signalling. Open Biol. 2019 Dec;9(12):190208. doi: 10.1098/rsob.190208. Epub 2019 Dec 18. PMID: 31847786; PMCID: PMC6936251.
[30] Kostyuk V, Potapovich A, Albuhaydar AR, Mayer W, De Luca C, Korkina L. Natural Substances for Prevention of Skin Photoaging: Screening Systems in the Development of Sunscreen and Rejuvenation Cosmetics. Rejuvenation Res. 2018 Apr;21(2):91-101. doi: 10.1089/rej.2017.1931. Epub 2017 Aug 28. PMID: 28661208; PMCID: PMC5910042.
[31] Bhattacharya S, Sherje AP. Development of resveratrol and green tea sunscreen formulation for combined photoprotective and antioxidant properties. J Drug Deliv Sci Technol. 2020;60:102000.
[32] Junco JJ, Mancha A, Malik G, Wei SJ, Kim DJ, Liang H, Slaga TJ. Resveratrol and P-glycoprotein inhibitors enhance the anti-skin cancer effects of ursolic acid. Mol Cancer Res. 2013 Dec;11(12):1521-9. doi: 10.1158/1541-7786.MCR-13-0237. Epub 2013 Sep 26. PMID: 24072817; PMCID: PMC3869897.
[33] Lim J-YY, Kim O-KK, Lee J, et al. Protective effect of the standardized green tea seed extract on UVB-induced skin photoaging in hairless mice. Nutr Res Pract. 2014;8:398. doi: 10.4162/nrp.2014.8.4.398.
[34] Lim HW, Arellano-Mendoza M-I, Stengel F. Current challenges in photoprotection. J Am Acad Derm 2017;76(3S1):S91–9.
[35] Chen AC, Martin AJ, Choy B, et al. A phase 3 randomized trial of nicotinamide for skin-cancer chemoprevention. N Engl J Med 2015;373:1618–26.
[36] Marrett LD, Chu MBH, Atkinson J, et al. An update to the recommended core content for sun safety messages for public education in Canada: a consensus report. Can J Public Health 2016;107:e473–9.
[37] Sarkar AK. An evaluation of UV protection imparted by cotton fabrics dyed with natural colorants. BMC Dermatol 2004;4:15.