Debunking the Myths of Sunscreen

Curtis Cole, PhD

Dr Cole, VP of R&D at Johnson and Johnson Consumer Products reviewed some of the facts and myths about the use of sunscreen.

Currently, there is lots of confusion about the use of sunscreen. Many believe that sunscreen use is doing more harm than good due to hormone disruption, “nano” materials, and organic versus inorganic filter-based products.

We know that ultraviolet radiation from the sun is the major cause of skin cancer and sunscreens diminish the amount of UV rays that are exposed to the skin.

Common Questions

Are physical blockers really different from chemical filters? It’s important to know that ZnO and TiO₂ have a semiconductor energy band gap and really act as absorbers and work like chemical filters.

What about sunscreen re-application? Do they need to be applied every two hours? Sunscreens will keep working indefinitely as long as they are photostable; however, re-application does help increase the protection and it is mandatory labeling by the FDA.

“Broad spectrum” is determined by critical wavelength. What do critical wavelengths really mean? Dermatologists should remember that critical wavelength does not necessarily imply protection. The new FDA labeling has changed what critical wavelength actually means.

Do SPFs greater than 50 provide more protection? Dr Cole reminds us that protection is directly proportional to the SPF number. Therefore, a higher SPF number is better protection for many conditions. Additionally, he presented data demonstrating that sunscreen application of a higher SPF  (SPF 85) provided superior protection when applied sparingly compared to lower SPF (SPF 30) sunscreens.

Summary

• Sun protection has improved immensely over the last ten years
• Sunscreens are only part of a multi-layer defense
• Sunscreen use will do far more good than harm