High SPF sunscreen and sun exposure

People using sunscreens with a high sun protection factor (SPF) do not necessarily spend more time in the sun than those who use sunscreens with a lower SPF. Sun exposure is an important environmental factor, which increases a person's risk of skin cancer. While daily sunscreen use has been shown to protect against skin cancer, some research also suggests that it may put sunbathers at risk of the condition. Sunbathers who use sunscreens with a higher value SPF may get a false sense of security from the increased protection against harmful UV rays and consequently spend even more time in the sun. Researchers from the Hôpital Saint-Louis in Paris, France did not support the hypothesis that a higher SPF induces a higher exposure by delaying the alarm signs or the hypothesis that mentioning 'high protection' on the label may induce longer exposure by giving an impression of safety. The study logically confirms that the use of higher-SPF sunscreens does reduce the number of sunburns in real life. Researchers investigated sun-exposure behaviour among 367 healthy women, with an average age of 39 years, at four French seaside resorts during the summer of 2001. The adults were offered free sunscreens and randomly divided into groups based on whether they were given SPF 40 sunscreens, labeled as "high protection," SPF 40 sunscreens labeled as "basic protection" or SPF 12 sunscreens labeled as "basic protection." The subjects were not told the actual SPF value of the sunscreen they received. However, neither the sunscreen label nor the SPF value appeared to influence the amount of time the study participants spent in the sun. Adults given "high protection" SPF 40 sunscreens spent an average 14.2 hours a week sunbathing, those given "basic protection" SPF 40 sunscreens spent 12.9 hours sunbathing and those given "basic protection" SPF 12 spent 14.6 weekly hours sunbathing. Sixty-three adults experienced sunburn, including six who had severe sunburns that caused pain for more than two days or blistering. The "high protection" or "low protection" labels did not seem to have an effect on the study participants' sunscreen use or whether they experienced any sunburns. Overall, adults who used the higher value SPF 40 sunscreens got fewer sunburns and used less sunscreen than those who used the SPF 12 sunscreen. The researchers conclude that public health recommendations should stress wearing clothing and hats and limiting midday exposures, but should not be reluctant to promote high-SPF rather than low-SPF sunscreens.