Tanning

Getting a tan or experiencing an alien abduction?

I had an uncle who died of skin cancer when I was a kid.  I didn’t get to see him after he got sick, but I know it’s a pretty nasty way to go.

Thinking about tanning makes me think about the risks associated with it, so I’ve been reading about skin cancer and the relative benefits of suntanning and sunless tanning (that is, tanning by applying a cream or spray instead of using light to burn your skin).  I’m very glad the idea we’re working with is sunless tanning.

Apparently skin cancer is by far the most common form of cancer, affecting more people than all other forms of cancer combined.  A fifth of Americans will develop some form of skin cancer during their lifetime.  That’s pretty startling.  Only a small fraction of those cases are fatal.  Skin cancer is far more common than lung cancer, but far less likely to be fatal.  The American Cancer Society says (PDF) that “an estimated 12,650 [skin cancer] deaths will occur in 2013.”  (By contrast, lung cancer killed nearly 159,000 Americans in 2008 and breast cancer kills about 40,000 annually, almost all women).

Oncologists are pretty critical of suntanning.  A couple years ago I listened to an episode of the  Diane Rehm Show where she interviewed experts on skin cancer about its relationship to sunscreen and UV exposure.  I got the impression that sun exposure was surprisingly dangerous and that the only non-cosmetic benefit of tanning with light is that ultraviolet radiation causes your skin to produce vitamin D.  Yet vitamin D is widely available in supplements and included in products like milk, so the consensus is strongly against suntanning.

I’ve always thought that getting a light “base suntan” was a good way to protect against sunburns (and therefore against skin cancer), yet I’ve just learned that the Mayo Clinic says otherwise:

Tanning under the sun or a sunlamp gives protection that is equivalent to a sun protection factor (SPF) of 4 or less, which translates into a little extra time in the sun before you start to burn. But the larger issue is that any change in skin color is a sign of damage from ultraviolet (UV) radiation. Repeated exposure to UV radiation — whether from the sun or a tanning bed — increases your risk of premature skin aging and skin cancer.

When Cristina pitched her business plan, I asked her if sunless tanning might offer some of the same protection from sunburns that I had always thought getting a natural suntan offered.  She didn’t seem to think so.

But the above quotation from the Mayo Clinic indicates that tans (natural tans, at least) do give a slight sun-protection benefit.  And having darker skin generally does offer some protection from sunburns and skin cancer.  The previously linked document from the American Cancer Society says that “melanoma is rare among African Americans; the lifetime risk of developing melanoma is 23 times higher among whites than among African Americans.”  Since some sunless tanning products use dihydroxyacetone to cause a chemical reaction with amino acids in the skin to darken the skin itself rather than just dyeing it a darker color, it still seems possible that sunless tanning could provide a small SPF benefit.  I wish there was some ongoing scientific research to answer that question, but I can’t find any real evidence to support the idea of an SPF benefit from sunless tanning.  The protection would be miniscule anyway.  Too bad; I was hoping I was on the trail of an underreported benefit of sunless tanning.

Nevertheless, the superiority of sunless tanning is obvious.  Doctors say that any darkening of the skin due to exposure to light is a sign of incipient UV damage.  The International Agency for Research on Cancer added tanning beds to its list of known carcinogens a few years ago.  If light-skinned people want darker skin, sunless tanning is clearly the safest and best option.

(There seems to have been less scientific research on testing the safety of sunless tanning, but at least one recent study (PDF) pronounced it safe.)

I’m convinced that Cristina’s sunless tanning idea is a project I can totally get behind.

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