We have always been told that applying sunscreen before a long day in the sun is the best way to prevent skin cancer. However, sunscreens have been getting a lot of bad press lately – reports that sunscreen may actually accelerate skin cancer have been surfacing.

Were we wrong all along? Do sunscreens cause more harm than good?
 
In spite of everything you have read or heard, sunscreens are not dangerous. In fact they are good for your health. Since sun exposure is the most preventable factor for skin cancer, there is a lot you can do to help protect yourself. Lower your risk of skin cancer by following these simple rules:

So what is all the controversy about?
 
SPF – It only tells you half the story
SPF is an accurate measure of how well a sunscreen blocks UVB rays, harmful ultraviolet rays that cause sunburns and DNA damage. It is this DNA damage that eventually leads to the development of skin cancer. The SPF rating does not indicate how well a sunscreen protects against UVA rays, which are not as dangerous but much more abundant in the atmosphere. UVA rays cause premature aging and age spots and will also damage DNA, which may also lead to the development of skin cancer. Most new sunscreens are broad-spectrum and protect against both UVB and UVA rays.
 
Chemical sunscreens – A case of mistaken identity
Sunscreens can be made of elements that scatter the UV rays like zinc or titanium, or chemicals that absorb the UV rays. Some of these chemicals have been negatively portrayed. Two of the most controversial ingredients are Oxybenzone and Methyparaben.  
 
Most chemical sunscreens contain Oxybenzone, a chemical used as an ingredient because it absorbs UVB and short-wave UVA rays. Oxybenzone is a by-product of benzophenone, which can attack DNA when illuminated. It has been theorized that if oxybenzone acts like benzophenone it may make this substance a photocarcinogen – a substance that causes cancer following illumination.    

Methylparaben, part of the paraben chemical class, is found in numerous sunscreens and face lotions. Parabens have received a lot of publicity regarding breast cancer because of their estrogen-like activity. However, Methlyparaben is non-toxic and is naturally occurring in blueberries.
 
Nanoparticles are finely ground up particles of zinc oxide or titanium dioxide. The white stuff lifeguards put on their noses has become cosmetically elegant and is now clear and smooth. Because of their small size some have theorized nanoparticles of zinc or titanium may migrate into the body. Of 15 scientific studies conducted by government, industry and independent researchers over the past decade, not one has detected human skin penetration.
 
Do sunscreens cause cancer?
Although the rates of skin cancer are rising, there is no evidence that sunscreens cause cancer. A more plausible explanation is that more people have more leisure time and spend more time outside. Most people do not use enough sunscreen to adequately cover their skin and most people forget to reapply. Sun exposure is the leading cause of skin cancer and premature aging.

You can have fun in the sun, just be smart about it. Wear sunscreen!     

 

 

Sources:

[i] Knowland, John; McKenzie, Edward A.; McHugh, Peter J.; Cridland, Nigel A. (1993). "Sunlight-induced mutagenicity of a common sunscreen ingredient". FEBS Letters 324(3): 309–313.

[ii] Al-Shamma A, Drake S, Flynn DL, Mitscher LA, Park YH, Rao GSR, Simpson A, Swayze JK, Veysoglu T, Wu STS (1981). "Antimicrobial Agents From Higher Plants. Antimicrobial Agents From Peganum harmala Seeds". J Nat Prod 44 (6): 745–747.

[iii] www.scientificamerican.com/article.cfm?id=do-nanoparticles-and-sunscreen...

[iv] Dennis LK, Beane Freeman LE, VanBeek MJ (December 2003). "Sunscreen use and the risk for melanoma: a quantitative review". Ann. Intern. Med. 139 (12): 966–78.