Dear B.K.: There were a flurry of media reports to this end about a year ago. Two studies of sunscreen use reported a higher incidence of melanoma in sunscreen users than in non-sunscreen users. There are two good reasons not to rely on these reports.

 

The first is that the investigators did not ask about skin type, only about sunscreen use. The people who are most likely to use sunscreen are those most susceptible to sunburn. These are fair skinned individuals who are most likely to develop skin cancer with or without the use of protective agents.

 

The second reason to question the validity of the reports is that older sunscreens blocked uV B but not uV A waves. UV A waves, which do not typically cause sunburn actually go deeper and do more damage to cellular DNA than the uV B waves. People who were using the sunscreen may have stayed out in the sun for longer periods, mistakenly believing that they were no longer at risk of solar damage.

 

I recommend staying out of the sun in the early afternoon when it is directly overhead, wearing a broad brimmed hat and protective clothing, and using sunscreen as a “back-up” for exposed areas. –Dr. Peterson