Report: Sunscreen ingredient does not cause cancer

SCHAUMBURG — An independent analysis published online in the Journal of the American Academy of Dermatology (JAAD) has determined that there is no evidence that the inclusion of retinyl palmitate in sunscreens can cause cancer in humans.

“Earlier this year, the Environmental Working Group issued a health warning that sunscreens containing retinyl palmitate could pose a cancer risk,” said dermatologist Dr. Henry W. Lim, chairman of the department of dermatology at Henry Ford Hospital in Detroit. “This warning garnered significant media attention and caused considerable confusion among the public. Our report should help dismiss the misinformation that sunscreens are not safe, as sunscreens are vitally important in reducing your risk for skin cancer, not causing it.”

Retinyl palmitate is approved by the Food and Drug Administration (FDA) for use in over-the-counter and prescription drugs, and it is also used as a food additive (e.g., to fortify low-fat milk, dairy products and breakfast cereals with vitamin A).

When used in sunscreen, retinyl palmitate is not an active drug ingredient (unlike sunscreen filters), but rather a cosmetic ingredient. In sunscreen, it can serve as an antioxidant to improve product performance against the aging effects of UV exposure or to enhance the aesthetic qualities of sunscreen.  

In the commentary published in JAAD entitled “Safety of retinyl palmitate in sunscreens: A critical analysis,” lead investigator and dermatologist Dr. Steven Q. Wang, director of dermatologic surgery at Memorial-Sloan Kettering Cancer Center in New York, explains that although retinyl palmitate was selected for testing by the National Toxicology Program (NTP), mere selection does not mean that the chosen compounds are dangerous or unsafe.

He explained that retinyl palmitate was mainly selected because of its widespread use in cosmetic and sunscreen products. Many common ingredients, such as aloe vera, nanoscale titanium dioxide, and zinc oxide are currently under review by the NTP.

One of the primary concerns about retinyl palmitate cited by the Environmental Working Group in its annual sunscreen report is that when the compound is exposed to ultraviolet A (UVA) radiation, it can result in the generation of oxygen radicals, or free radicals.

Since 2002, there have been eight in vitro (test tube) studies using mouse lymphoma cell and human skin Jurkat T-cell cultures demonstrating that retinyl palmitate can produce free radicals, which can disrupt cell function.

“Despite the concerns raised by these non-human studies, retinyl palmitate operates within the skin as only one component of a complex antioxidant network,” said Dr. Wang. “For example, when a sunscreen with retinyl palmitate is applied to the skin, a number of antioxidants work together to alleviate the risk of free radical formation seen in these in vitro experiments. If studied on its own — outside of this environment — its antioxidant properties can rapidly be exhausted, allowing the production of oxygen radicals.

“In these non-human studies, retinyl palmitate was the only compound studied — making the biological relevance of these findings to humans unclear.”

Source: American Academy of Dermatology on PRNewswire-USNewswire