The American Association of Dermatology (AAD) has just issued a statement saying that “no evidence that the inclusion of retinyl palmitate in sunscreens can cause cancer in humans”.

This conclusion was made by a team led by Steven Q. Wang, MD, FAAD, director of dermatologic surgery at Memorial-Sloan Kettering Cancer Center in New York after looking at data from various studies conducted since 2002.

Concerns about retinyl palmitate in sunscreen were ignited by the Environmental Working Group (EWG), which earlier this year said that when retinyl palmitate is exposed to UVA radiation, it can result in the generation of harmful 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.

Dr Wang’s rebuttal of the EWG concerns is based on three things: the studies were conduction on animals, not humans; the mice (according to Wang) are “highly susceptible to the effects of UV radiation and can develop skin cancer or other skin abnormalities within weeks of UV exposure, even in the absence of retinyl palmitate”; and in the studies retinyl palmitate was used on its own, not with other antioxidants.

At this stage, I don’t feel that the AAD or the EWG make a watertight case one way or the other. The FDA has still not published its own assessment of the available research data.