Keep Your Skin Safe This Summer
About half of young adults report getting at least one sunburn per year.1 As we plan to spend time outdoors this summer, we must remember to also avoid excessive sun exposure to protect ourselves from free radical damage and skin cancer. Recurrent sunburn may result in later life skin cancer.
Melanoma, the deadliest form of skin cancer, has been steadily on the rise since the 1970s and since 2000, melanoma incidence has risen at a rate of 1.9% per year.2 It is essential to protect your skin from the sun’s rays.
To keep our skin healthy, we must seek shade often, wear protective clothing, and avoid mid-day sun or too much time in the sun. Also, when choosing a sunscreen, it is important to use the safest and most effective methods of sun protection.
What about vitamin D?
Under our present atmospheric conditions, unprotected sun exposure for extended periods is not safe. We should not rely on the sun to provide all our needs for vitamin D because it needlessly increases the risk of skin cancer and premature aging of the skin. Supplementation is the safest method of obtaining sufficient vitamin D.
UVB rays cause sunburn; both UVA and UVB rays contribute to skin cancer. Many sunscreens do not protect against UVA rays. The SPF listed on sunscreens refers only to UVB protection.
Chemical sunscreen absorbs and deflects the sun’s rays away from the skin through a chemical reaction. Sunscreens vary in their ability to protect against UVB and UVA rays depending on the ingredients used.
Physical (mineral) sunscreen creates a physical barrier between the UVA and UVB rays and the skin. Physically blocking sunlight from penetrating the skin is the most effective way to block UVA and UVB radiation.
Sunscreen ingredients to avoid
Vitamin A is often listed on sunscreen labels as an antioxidant that can fight skin aging. Vitamin A is an antioxidant, but in isolation it could be dangerous, both in supplements and for the skin. However, according to animal studies, sunscreens may actually promote the progression of skin cancer if they contain vitamin A.3
Chemical sunscreen ingredients are absorbed into the blood following application to the skin and it is not yet known whether this causes adverse health effects.4 Chemical sunscreen ingredients, such as oxybenzone and OMC, are also endocrine disruptors — chemicals that have the ability to mimic, inhibit or alter the action of the body’s natural hormones. Exposure to endocrine disruptors, for example BPA and DDT, have been linked to early puberty in children and hormonal cancers in adults.5 Endocrine disrupting effects of chemical sunscreens have been reported in animals, and they are likely to affect human health as well.6 Oxybenzone has been detected in human urine samples, suggesting that this sunscreen chemical is absorbed into the blood.7 In addition, a number of studies have linked allergic reactions to chemical sunscreens, particularly oxybenzone.8
Mineral sunscreens are safer than chemical sunscreens, but some mineral sunscreens are safer than others
Mineral sunscreens most commonly contain either titanium dioxide or zinc oxide or a combination of these two, and these are preferable to chemical sunscreens. These minerals do not penetrate as deeply into the skin as chemical sunscreens. They lie on top of the skin and penetrate only into superficial layers, absorbing UV rays before they can damage the skin beneath. Zinc oxide has been found to be superior to titanium dioxide in absorbing UVA rays.9
Certain products use nanoparticles of titanium dioxide and zinc oxide to make the sunscreen more easily absorbed by the skin and therefore more transparent — but this might allow the small particles to penetrate the skin and enter the bloodstream. The studies done so far suggest that these nanoparticles have a limited ability to penetrate the skin, but they can cause oxidative stress and DNA damage to skin cells.10 Also, inhaled nanoparticles may damage lung tissue and also enter the bloodstream and reach other organs.11 Additional studies are needed in order to definitively determine whether these products are safe.
Mineral sunscreen without nanoparticles is the safest choice
Non-micronized titanium dioxide or zinc oxide sunscreen is the safest choice for protecting against UVA and UVB rays. Unfortunately, sunscreen labels most often do not disclose whether the product contains nanoparticles.
I recommend and make available a safe and effective sunscreen line that uses nonmicronized zinc oxide. Green Screen Organic sunscreen protects against both UVA and UVB without the use of nanoparticles or harmful chemicals, and is made from all natural and edible grade organic ingredients. Kabana’s Green Screen Organic sunscreen is on the Environmental Working Group’s list of Best Sunscreens and meets their criteria for safety and efficacy. Of all the physical sunscreen products that receive the highest Environmental Working Group rating, Green Screen is one of the very few that does not contain nano- or micro-sized particles. We have contacted and communicated with the technical departments of many sunscreen companies to find a product that does not contain nanoparticles. Green Screen® does leave a tint on your skin when applied — that’s why it is available in both white and flesh tone. The advantage is that you can easily see if you are protected or not and whether it is time to reapply the sunscreen if need be.
1. U.S. Centers for Disease Control and Prevention. Sunburn and Sun Protective Behaviors Among Adults Aged 18–29 Years — United States, 2000–2010. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6118a1.htm?s_cid=mm6118a1_w
U.S. Centers for Disease Control and Prevention. Use of Indoor Tanning Devices by Adults — United States, 2010. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6118a2.htm
2. National Cancer Institute. Surveillance Epidemiology and End Results: Fast Stats. http://www.seer.cancer.gov/faststats/index.php
U.S. Centers for Disease Control and Prevention. Skin Cancer Trends. . 2013. http://www.cdc.gov/cancer/skin/statistics/trends.htm.
3. Environmental Working Group. http://breakingnews.ewg.org/2011sunscreen/sunscreens-exposed/the-problem-with-vitamin-a/
4. Janjua NR, Kongshoj B, Andersson AM, Wulf HC. Sunscreens in human plasma and urine after repeated whole-body topical application. J Eur Acad Dermatol Venereol. 2008 Apr;22(4):456-61.
Hayben H, Cameron, M. Roberts H, et al. "Systemic Absorption of Sunscreen after Topical Application." The Lancet 1997;350:9081.
Gustavsson G, Farbrot A, Larko O. "Percutaneous Absorption of Benzophenone-3, a Common Component of Topical Sunscreens." ClinExp Dermatol 2002;27(8):691-4.
5. Cohn BA, Cirillo PM, Christianson RE: Prenatal DDT exposure and testicular cancer: a nested case-control study. Arch Environ Occup Health 2010;65:127-134.
Cohn BA, Wolff MS, Cirillo PM, et al: DDT and breast cancer in young women: new data on the significance of age at exposure. Environ Health Perspect 2007;115:1406-1414.
Maffini MV, Rubin BS, Sonnenschein C, et al: Endocrine disruptors and reproductive health: the case of bisphenol-A. Mol Cell Endocrinol 2006;254-255:179-186.
Roy JR, Chakraborty S, Chakraborty TR: Estrogen-like endocrine disrupting chemicals affecting puberty in humans--a review. Med Sci Monit 2009;15:RA137-145.
6. Schlumpf M, Schmid P, Durrer S, et al. Endocrine activity and developmental toxicity of cosmetic UV filters--an update. Toxicology. 2004 Dec 1;205(1-2):113-22.
Schlumpf M, Cotton B, Conscience M, et al. In vitro and in vivo estrogenicity of UV screens. Environ Health Perspect. 2001 Mar;109(3):239-44.
7. Calafat AM, Wong L, Ye X, et al. Concentrations of the Sunscreen Agent, Benzophenone-3, in Residents of the United States: National Health and Nutrition Examination Survey 2003–2004. Environ Health Perspect. 2008 Jul;116(7):893-7.
8. Szczurko C, Dompmartin, Michel M, et al. "Photocontact Allergy to Oxybenzone: 10 years of Experience." Photodermatol PhotoimmunolPhotomed 1994;10(4):144-7.
Schauder S, Ippen H. "Contact and Photocontact Sensitivity to Sunscreens: Review of a 15-year Experience and of the Literature." Contact Dermatitis 1997;37(5):221-32.
9. Pinnell SR, Fairhurst D, Gillies R, et al. Microfine zinc oxide is a superior sunscreen ingredient to microfine titanium dioxide. Dermatol Surg. 2000 Apr;26(4):309-14.
10. Filipe P, Silva JN, Silva R, et al. Stratum corneum is an effective barrier to TiO2 and ZnO nanoparticle percutaneous absorption. Skin Pharmacol Physiol. 2009;22(5):266-75.
11. Liu R, Zhang X, Pu Y, et al. Small-sized titanium dioxide nanoparticles mediate immune toxicity in rat pulmonary alveolar macrophages in vivo. J Nanosci Nanotechnol. 2010 Aug;10(8):5161-9. Tang M, Zhang T, Xue Y, et al. Dose dependent in vivo metabolic characteristics of titanium dioxide nanoparticles. J Nanosci Nanotechnol. 2010 Dec;10(12):8575-83.