Your thin American Apparel tee is sufficient sun block, and other sunscreen myths

Note: Author not depicted in this photo.

Note: Author not depicted in this photo. (from Flickr by Brave Heart.)

Growing up in a small town I had the image of city folk as soft pasty-white people whose only glimpse of the outdoors was gained by peering over their window-mounted air conditioners. But anyone who has lived for even a minute in New York City knows this is untrue. New Yorkers walk. We gotta. And walking means that we spend more time outside than non-New Yorkers give us credit for. I have a truly decent farmer’s tan despite this rainy summer. So why is it that my impending trip to Tucson has made me think of nothing but sunscreen? Tucson in August is like a ghost town, where you only get brief flashes of people out of doors as they dash from their car to the box store.  But I am obsessed with keeping my skin protected (I’m not getting any younger, and this kind of stuff has started to occupy my day), but when I really thought about how to properly use sunscreen, I realized that I have collected a bunch of notions that may not be steeped in fact. So, on with my research hat (and apparently off with my dunce cap).


I’m just gonna wear SPF 1,000,000 and I will be fine… WRONG. The SPF, or sun protection factor, number is an indicator of the percentage of UV rays that are absorbed, scattered, or reflected by the product. An SPF of 15 filters approximately 92% of the UV rays, or put another way, with an SPF of 15 your skin can be exposed to 15 times the amount of UV exposure that it would normally take to burn. An SPF of 30 protects your skin from 97% of UV rays, and there is some debate about whether or not products with higher SPF numbers provide significantly better protection than 15. The majority of recommendations state that wearing products with an SPF of at least 15 is sufficient to prevent burns. So I probably wasted money on that SPF 95 I just bought.

I needn’t bother applying sunscreen to areas that are covered by my clothes… WRONG. While tightly woven fabrics block most of the sun’s rays, your average t-shirt has an SPF of less than 10. Apparently, there are clothing manufactures that are producing clothes with higher UVA/UVB blocking ability, and there are products that you can use on your clothes to increase their SPF (I’ll let you google that stuff if you’re interested).

I put on a moisturizer with SPF 15 everyday, and when I use make-up that also has SPF rating, I like to pretend that I am more protected… WRONG. SPF ratings are not additive. 15 + 15 = 15 However, it is important to apply sufficient amounts of the product to achieve the full effect. A study published by some dermatologists in Denmark indicated that the quantity of product applied is exponentially related to the SPF. So apply well and often.

UV can’t get through glass, and since I will be hunched over my computer all day, I needn’t bother applying sun screen… WRONG. I was told by my high school science teach that you cannot get a sunburn from sun filtered through glass. And this is true! Sunburn causing UVB rays cannot penetrate glass. However, most glass does not filter UVA rays, which do affect your skin’s health. So while I may not burn while sitting indoors, the sun is still causing my skin to age (crap!). And of course, I am being exposed to the sun when I pop out to the deli for coffee, or move my car on alternate side parking days.

So, this post started innocently enough. I felt I may have collected some preconceived notions about sunscreen usage and I did a little research to educate myself on the topic. Who knew I would stumble into a whole new field of woo and conspiracy! It appears that there are those who believe that sunscreen usage is a scheme made up by doctors and corporations to make money, and that sunscreen use actually causes harm, not good. When I googled “sunscreen myths” this was the second hit, “Sunscreen Myths: How Sunscreen Products Actually Promote Cancer.” The thesis of this article is that rampant sunscreen use interferes with our ability to make vitamin D, and we know that sun exposure is important for vitamin D production from the interpretative dance I blogged about last week, so this is absolutely true. There is also growing evidence that vitamin D may influence the risk of certain types of cancer. The slant the “Myth” article gives this evidence is:

The scientific evidence, however, shows quite clearly that sunscreen actually promotes cancer [emphasis theirs] by blocking the body’s absorption of ultraviolet radiation, which produces vitamin D in the skin.

After a recent and quite thorough review of the literature conducted by researchers around the world, the Office of Dietary Supplements at the NIH published this statement:

Laboratory and animal evidence as well as epidemiologic data suggest that vitamin D status could affect cancer risk… Further research is needed to determine whether vitamin D inadequacy in particular increases cancer risk, whether greater exposure to the nutrient is protective, and whether some individuals could be at increased risk of cancer because of vitamin D exposure.

So while would have us believe that increasing levels of vitamin D is inversely related to your chances of cancer, the research indicates that it is not at all clear how or in what quantity vitamin D might affect cancer risk. But ok. Let’s review. Sunscreen prevents vitamin D production, but most of us (well, at least me) are not applying sunscreen as thoroughly as we think, are getting sun exposure through our clothes, and are getting some vitamin D in our diets. Are we being conspired against by “commercially influenced” doctors to buy massive quantities of sunscreen? I’ll just point out that the “Myth” article also claims that UV exposure doesn’t actually cause sunburn and that a high berry diet would protect our skin as effectively as sunscreen. And then I will leave you with a list of heavy organizations that all promote the use of sunscreen (I suppose they could ALL be in cahoots, but the gain to each individual organization is ambiguous):

American Academy of Dermatologists

American Cancer Society

Center for Disease Control and Prevention

Environmental Protection Agency, they sing a song about it

World Health Organization


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One Response to “Your thin American Apparel tee is sufficient sun block, and other sunscreen myths”

  1. Mary mary Says:

    my mom used to always make me swim in a t shirt. child abuse!

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