Surprised? We were too, so we examined the medical research in greater detail. The majority of publications suggest that sunscreen use is linked to increased melanoma risk. This paper in particular presents compelling data.
it is important that you as a label reader undertand that this is not the same as saying "Sunscreens cause melanoma." Medical research largely finds a positive correlation with sunscreen use and melanoma, with certain types of people at higher risk. The well-controlled research paper linked above determined that people with the highest increased risk (up to 8x) are people with light complexions, blonde or red hair, who do not tan well and use higher SPF (high petrochemical content) sunscreens frequently.
Why might this be?
The paper proposes the following:
1. People who use sunscreen most frequently are often the most UV sensitive,
2. High sunscreen users also spend significantly more time outside and accumulate more UV damage.
3. Increased risk may be related to particular wavelength damage that results from UVB-only sunscreens.
Kabana adds two more possibilities:
4. Mass-market sunscreen manufacturers use misleading marketing terms on their labels, such as 'waterproof,' 'sweatproof,' 'sunblock,' and 'all-day protection.' None of these claims accurately represent a sunscreen's capacities, and all of them were effectively made illegal through exclusion in the 1999 Final Sunscreen Monograph, published by FDA in the Federal Register, precisely because they inaccurately describe the UV protection afforded by sunscreen products. This false sense of security effectively elevates skin cancer risk because consumers don't reapply sunscreen properly.
5. The studies do not control for the TYPE of sunscreen used - mineral or petrochemical. Petrochemical sunscreens are inherently toxic and also damage DNA, particularly when UV light breaks their chemical bonds and creates free radicals. The highest risk group uses sunscreens with the highest levels of petrochemical active ingredients. It is reasonable to think that they trade UV-caused DNA damage for chemical-caused DNA damage of the type that causes melanoma preferentially over other skin cancers. We'd like to see a study that controls for this possible effect.
Regardless, both UV and chemical exposures will damage your DNA and elevate skin cancer risk. You need to minimize both. Kabana has always advocated shade as the best possible UV protection, but where that's impossible, Green Screen® Organic and Natural Sunscreens are the healthiest broad spectrum UV protection products available to you and your family.
A great deal of additional information about sunscreens useful for the label reader can be found on Wikipedia.
