I think there is way too much hype about SPF. More important to me is getting plenty of vitamin D (the sunshine vitamin), which you can only get from the sun. Wearing SPF blocks the absorption/creation of vitamin D, and there are very few dietary sources of this really important vitamin that is crucial for bone health (among other things like cancer prevention). I think it's important for people to limit excessive tanning (from the sun and from beds), but what they are never told related to SPF is that wearing it all the time also hurts their health in other ways related to this defeciency. To get your daily quota, you need 15 minutes of full sun exposure to the arms and legs each day--without SPF--which likely will not increase your risk of skin cancer. Outside of that, be careful the rest of the time.

I find that if i don't wear sunscreen on my face I am pink in 15 minutes. Just my face though, not my chest arms or legs.

The actual SPF number refers to a factor by which the time it takes you to burn is multiplied by when wearing the sunscreen. So if you normally take 10 minutes to get a sunburn you will have 150 minutes before a burn in SPF 15 sunscreen. Or to put it another way, You'll be getting the equivalent of 1 minute of unprotected exposure in 15 minutes. UVB is more directly related to skin cancer because it directly damages the DNA, but UVA can still contribute because it penetrates deeper into the skin (being a shorter wavelength) and while it's there it goes nuts knocking electrons of things (ie, creating free radicals) which then run around and pluck electrons off of other things to make up for it, which can also damage the DNA.

PHEW. Well. I'm a gigantic nerd.

ACTUALLY, UVA has a longer wavelength than UVB, which has a shorter wavelength, higher frequency and has more energy, which means it penetrates skin more deeply and does greater damage to cells in the dermis. UVB is associated with melanoma, UVA is associated with basal and squamous cell carcinomas.

As this article correctly describes, (which is so nice to see for a change in editorial media!) SPF 30 is not twice the protection of SPF 15 - it is only ~4% more protection. SPF is a very poor way to describe a sunscreen for this reason. The mass sunscreen marketeers have established this number because it helps them sell sunscreen, (people think it's linear protection, which it isn't) but the American Academy of Dermatology recommends using SPF 15 or higher sunscreen and REAPPLYING every 2 hours because sunscreen simply doesn't stay on your skin for much longer than this period when you're outside, and disappears more quickly if you're swimming, sweating, diving in the sand or just rolling over on your towel. All these activities remove sunscreen and reduce the protection level. Not to mention the fact that petrochemical sunscreens are toxic in themselves, are associated with estrogenic effects and many don't biodegrade.

Additionally, terms that were made illegal to use on sunscreen labels as of FDA's 1999 (yes, 8 years ago!) OTC monograph are; "sunblock" "waterproof" "sweatproof" and "all day protection" precisely because no such product exists. It's all marketing smoke and mirrors that put you as a consumer at higher risk for skin cancer, YET all mass marketed sunscreens still use these terms because FDA doesn't regulate it and changing to the approved terms "water resistant" and "sunscreen" are deemed to reduce competitive advantage. It's not surprising that skin cancer is on the rise. Search 'Lerach' (the law firm) and 'Sunscreen' on google and you'll discover a consumer fraud lawsuit filed against the big five sunscreen manufacturers precisely for this reason. I hope Lerach and Co. sock it to them.

thanks for the info fit

I hardly wear SPF - only during swimming and at the beach. During walks and outings, I tend to wear a hat and put sunscreen only on exposed parts of my upper body and neck because I don't like the feel of it on my face - is that bad?

nikolem2 - I thought vitamin D comes from cod liver oil and some other types of fish and a whole bunch of other food sources too.

I spoke to my dermatologist about the best sunscreen to use and he recommended a brand called Blue Lizard, he uses it on his family (which I think says a lot). He said that you really need to make sure there are PHYSICAL barriers (yes, it acts as a chemical barrier on the skin that prevents the absorption of the rays) in the sunscreen to protect from the UVB rays. It only has a physical barrier if it has the ingredients of zinc oxide or titanium oxide. If it doesn't have those ingredients, he told me I was literally wasting my money on sunscreen. Figured I'd pass that on to y'all.

You are welcome, mandiesoh, info fits are my specialty, particularly about sunscreen as I've been in the business and dermatology drug development for over a decade.

Regarding the vitamin D issue and that sunscreen prevents vitamin D production, this is entirely scientifically unfounded. The necessary vitamin D that one needs is produced in a matter of minutes of sun exposure. The American Academy of Dermatology also debunks this myth here: http://www.aad.org/public/News/NewsReleases/Press+Release+Archives/Skin+...

The only way to determine whether a skin care product is natural and good for you it so read the ingredient lists. If I can't understand the labels, its very difficult to determine whether or not a formula is good for me. How does it make you feel?

Thanks for the article! It helped clarify some stuff I was wondering about.

what a great article. and i'm learning so much about sunscreens and what not from this article and the responses. thanks everyone who has contributed. being very(VERY) fair myself, i need to be informed because i've lost a relative to cancer that began as skin cancer and spread.

I think sunscreens are a scam. They make money on fear to support their product.