Sunscreen and Skin Cancer

 

What Doctors Don't Tell You E-News have just published some controversial research on sunscreens and skin cancer.  As many of us prepare for holidays in the sun, or wait for some warmer weather to arrive in the UK, we want to be sure that  we are protecting skin as safely as possible. Sunscreens that contain zinc oxide are generally termed 'mineral' as opposed to 'chemical'. The main difference is that a chemical sunscreen contains UV filtering ingredients that are absorbed by the skin, whereas a mineral sunscreen contains inert UV protective ingredients, such as zinc oxide or titanium dioxide, which sit on top of it. Mineral sunscreens therefore provide a barrier to the sun, which those with sensitive skin may find less irritating.  However, it is the use of zinc oxide that is the topic of this review:

 

Far from protecting you from skin cancer, many popular sunscreen products directly cause it. Zinc oxide in the sunscreen reacts to direct sunlight, damaging cells and increasing the risk of skin cancer.

Ultraviolet light from the sun starts a chemical reaction in the zinc oxide that releases free radicals – unstable molecules – that interfere with the DNA in cells. This, in turn, makes them more vulnerable to skin cancer and other diseases.

Researchers from Missouri University of Science and Technology estimate that the zinc oxide begins to react within an hour of being exposed to the sun.  In one laboratory test, half the cells in a zinc oxide solution had died after three hours’ exposure to UV light, and 90 per cent had died after 12 hours.

However, say the researchers, it’s still better to wear sunscreen than to go out into the sun without protection – or, perhaps, buy a sunscreen that doesn’t contain zinc oxide.

(Source: Toxicology and Applied Pharmacology, 2012; publication date to be decided).
 
Some companies state that it is the size of the zinc oxide particle that is significant, a larger particle being safer to use. However, for the time being it would seem a good idea to use as natural a sunscreen as possible, that does not use zinc oxide. The Green People sell a natural-based sunscreen, without zinc oxide, in a variety of sizes, including handbag and trial size and also one suitable for children. I haven't yet used this but the reviews sound encouraging. 
The always-changing information that we hear regarding sun and skin cancer needs to be balanced with the fact that we need some exposure to sunshine to encourage the manufacture of vitamin D in our bodies, so it seems to me that we need to learn a new kind of responsibility in the sun, which may include wearing hats and lightweight clothes when we have extended periods in the sun.