Researchers conducted a weeklong study tracking the sun exposure of vacationing sunbathers who used sunscreen with higher and lower levels of sun protection factor (SPF), finding sunbathers who routinely use a high-protection sunscreen are not necessarily more likely to spend longer periods of time in the sun than those favoring sunscreens offering only basic protection.

The findings appeared in the August issue of Archives of Dermatology, but the researchers’ conclusion contradicts previous studies suggesting sunscreen use might be a risk factor for melanoma.  The rate of skin cancer continues to increase, despite public health policies stressing the dangers and advocating preventative measures by minimizing sun exposure, wearing protective clothing and using sunscreen.

Skin cancer is the most common of all cancers, accounting for nearly half of all cancers in the United States.  Most of the 1 million cases of nonmelanoma skin cancer diagnosed every year are sun related, according to the American Cancer Society, and sun exposure has been shown to be the single most important environmental factor in the development of skin cancer. 

The ACS says that while the cause of melanoma skin cancer is not known, there are several risk factors, including too much exposure to UV radiation, and the main source comes from sunlight.  Studies have suggested higher protection from sunlight by using a more potent sunscreen may induce longer sun exposure by postponing warning signs such as sunburns or by providing a false impression of safety in the sun, but in this study, 367 vacationers from four French seaside resorts were given one of three sunscreens: SPF 40 - labeled “high protection”, SPF 40 – labeled “basic protection” and SPF 12 labeled “basic protection”. 

Participants were asked to complete questionnaires detailing their sun exposure and protection at half hour intervals throughout the day, and the researchers wrote neither SPF nor labeling was associated with differences in durations of sunbathing during the week.  Based on the population surveyed – 80 percent of the participants were women and the average age was 39 – the researchers said their findings did not support the hypothesis that a higher SPF induces a higher exposure by delaying the alarm signs nor the hypothesis that mentioning “high protection” on the label may induce longer exposure by giving an impression of safety.

The best offense to suffering skin damage, including skin cancer, is to use sunscreen with an SPF of at least 15 liberally.  Many people fail to adequately apply and reapply suntan lotion, especially after swimming, toweling dry or perspiring.