Massachusetts General Hospital | Cancer Center

Avoiding the dangers of sun exposure

Dr. David Fisher on sun safety and cancer protection

13/Jul/2009

There are consequences to unprotected sun exposure

Summer may have taken awhile to emerge in New England this year, but the sun’s ultraviolet (UV) rays are as strong as ever. Although it’s tempting to run out and hit the beach without any coverage, there are consequences to unprotected sun exposure – one of the most significant being skin cancer. Dr. David Fisher, chief of Dermatology at Massachusetts General Hospital, offers advice on how to make this your safest summer yet.

When your skin is exposed to the sun, “there is a short-term cosmetic change with long-term photo damage,” says Fisher. Sun exposure accelerates the skin’s aging process, which contributes to an increase in wrinkles and moles. It also increases one’s risk of developing skin cancers.

While the best way to protect oneself from UV radiation is to stay out of the sun, Fisher describes a “middle ground” for those who want to be outdoors. This consists of avoiding peak hours (12 – 2 pm) and prolonged sun exposure, and being judicious about wearing a hat and covering the skin. Of course, sunscreen should be used – and the fairer the skin tone, the more vulnerable one is to burning.

“It’s important to apply sunscreen thoroughly and frequently, such as after swimming or sweating,” says Fisher. “If you must be outside during peak hours, apply every two hours or less.” He notes that many people forget to reapply, getting sidetracked by their outdoor activity or thinking that one coat was enough.

Cancer risk

Fisher stresses that sun protection factor (SPF) is not cancer protection factor or what he calls “CPF.” He says there is a clear lowered risk of certain types of skin cancer, such as Squamous cell carcinoma, in those who use sunscreen. The magnitude of the protection provided by sunscreen for other types of skin cancers, such as melanoma, is still being studied.

“From what we know currently, sunscreen does not assure protection from skin cancer, though it’s excellent at preventing sun burning and certain forms of skin cancer,” says Fisher. “Therefore it’s certainly important to use it but to also remain cautious overall about sun exposure.”

Fisher warns that the risk for developing skin cancer even if you don’t burn is very real. He cites indoor tanning salons, where clients do not burn or else they wouldn’t remain in business, as an example. Large studies have shown a link between indoor tanning and the development of skin cancers. With this knowledge, people should remain cautious about sun exposure beyond avoiding sunburn. Fisher suggests taking a break from the sun to complement the protection provided by your sunscreen.

“Look for shade; shade is your best friend,” he says, adding that, “Hats are great. It shouldn’t be a straw hat with giant holes in it that will let sun in, and the same goes for clothing.”

Viable vitamin D

Some people argue that sun exposure is a good way to get vitamin D. Some even go so far as using tanning salons to get it. While Fisher confirms that vitamin D is “unequivocally a crucial element of the human body,” he argues that there are simple ways to get it aside from ultraviolet radiation, such as taking a daily vitamin D pill.

“There is an advantage to taking a pill rather than getting vitamin D through UV radiation and that advantage is that you know how much you have taken,” says Fisher. “If you go into the sun, you don’t know the strength of the UV radiation for that day, you don’t know how it penetrates your skin pigment – you don’t really know how much vitamin D your skin is producing. The only thing you can be confident of is that you’re increasing your risk for skin cancer”

Fisher says getting Vitamin D through a supplement is getting it “clean” whereas getting it through UV exposure is getting it “with a carcinogen.”

“The tanning industry has been distorting the message on UV and vitamin D to imply that there’s something unique about ultraviolet radiation as a “natural” means to get it, whereas the vitamin D you take in a vitamin pill achieves the identical medical benefits, to the best of our knowledge – but without the cancer-causing risk of radiation exposure.”

He says the best medically advisable way of being healthful with respect to vitamin D is to ask your doctor to check your vitamin D level and if you are deficient, your doctor can easily recommend a daily supplement.

Learn more about the Dermatology Service and the Cancer Center at Mass General.