Sunbathers wearing sunscreen labeled as "high protection" did not spend more time in the sun during a week-long vacation compared to those wearing "basic protection" sunscreen, according to an article in the August issue of Archives of Dermatology.
"Sun exposure is the most important environmental factor involved in the development of skin cancer," according to background information in the article. Melanoma has had one of the greatest increases in incidence among solid tumors in the past three decades and accounts for the vast majority of skin cancer deaths. Although daily sunscreen use has been shown to prevent squamous cell skin carcinoma, several studies suggest that sunscreen use may be a risk factor instead of a protective one for melanoma. Some believe that higher protection by stronger sunscreens may encourage more time in the sun by delaying warning signs such as sunburn, giving one a false sense of safety.
Alain Dupuy, M.D., M.P.H., from the Hospital Saint Louis, Paris, and colleagues, conducted a week-long, randomized, controlled trial during the summer of 2001 to determine the effect of sunscreen protection on sun-exposure behavior. Three hundred sixty-seven vacationers from four French seaside resorts were given one of three sunscreens: SPF 40 labeled as "high protection," SPF 40 labeled as "basic protection," and SPF 12 labeled as "basic protection." No mention of actual SPF was made on the labels. Participants were given an initial questionnaire about general sun-exposure behavior and completed self-administered questionnaires each evening, detailing their sun exposure and protection for every half-hour period during the day. Eighty percent of the participants were women, with an average age of 39 years.