The impact of topical photoprotectants intended for daily use on lifetime ultraviolet exposure

Background Exposure to solar ultraviolet (UV) radiation is believed to be an important contributor to facial photoaging. Daily application of topical photoprotectants is thought to mitigate this process. Objectives To examine the importance of a number of independent factors in reducing the lifetime UV exposure of facial skin achieved by daily use of photoprotective products. Methods A behavioral model of solar UV exposure to the face is incorporated with the spectral profile of two different candidate topical products, the age at which regular photoprotection begins, the SPF of the products, and whether the product is applied year-round or just in the summer months to examine the reduction in lifetime UV exposures achieved by daily use of photoprotective products. Results The results show that regular use of topical photoprotective agents reduces significantly lifetime UV exposure to the face compared with nonuse. Analysis of variance shows that the most important factor is to begin regular daily use early in life. The SPF and spectral profile of the product is of lesser importance, as is whether daily use is confined to the summer months rather than year-round. Conclusions While it remains unproven and speculative, there is good reason to suppose that regular use of daily facial topical products containing UV filters, particularly if started early in adult life, will be translated into fewer visible signs of aging later in life.