In case you re still wondering whether you really need to have someone rub sunscreen on your back at the beach, new evidence for the benefits of sun block have been published in the Journal of the American Medical Association. Researchers from the departments of dermatology at Northwestern University, Harvard Medical School, and Beth Israel Deaconess Medical Center in Boston ran the first randomized controlled study on the effects of sunscreen use in melanoma prevention, and their findings support what should already be common sense.
Dr. June K. Robinson and Dr. Michael Bigby randomly assigned over 1,600 adults to regular sunscreen use or as a control group discretionary sunscreen use, during a five-year treatment period. While both groups had similar risk factors, one group was asked to apply a broad-spectrum sunscreen with sun protection factor (SPF) of 16 every morning, and to reapply it as necessary, while the discretionary group s use ranged from sporadic to none at all. As recorded in a 10-year follow-up period, among those who regularly applied sunscreen, there was a 50 percent reduction in the incidence of primary melanoma and a 73 percent decline in invasive melanoma.
While these rates of prevention may not seem as high as already diligent sunscreen users might expect, ACSH's Dr. Gilbert Ross notes that this is most likely due to the relatively small study size. Also, perhaps using a sunscreen with an SPF of 30 would have resulted in even higher prevention rates, he says. The 68,000 diagnoses of melanoma in the past year, he points out, should persuade everyone to heed this study s recommendation to wear sunscreen. Exposure to UV radiation is the only contributing factor to melanoma that we can control.
People at high risk for skin cancer include those with fair skin, freckling, and tendency to sunburn. Anyone with these risk factors should thoroughly apply sunscreen before venturing out into the sun, and should reapply it every few hours, especially after swimming.