A press release from the Environmental Working Group says the chemical retinyl palmitate, found in many sunscreens, accelerates the development of skin tumors when it is applied to skin exposed to sunlight, and that this relationship has been confirmed.
“The NTP assessment, confirmed by its advisory board of 11 scientists from leading academic medical and industry research groups, found that when test animals coated with a mix of retinyl palmitate and skin cream are exposed to ultraviolet light, a major component of sunlight, the cream with retinyl palmitate has the perverse effect of stimulating the growth of skin tumors.” (Source: EWG)
The NTP referred to in their quote is the National Toxicology Program and it is made of up of three federal agencies:
* National Institute of Environmental Health Sciences
* National Institute for Occupational Safety and Health
* National Center for Toxicological Research
Sunscreen is supposed to prevent the development of skin tumors, not stimulate them, so this news is probably shocking to many who have used popular brands such as Banana Boat, Coppertone, Hawaiian Tropic, and Panama Jack which sell products containing retinyl palmitate. Actually the Environmental Working Group conducted a survey of sunscreens and found over 200 contain the chemical.
If you want to see their guide to the best sunscreens, visit their site. They also have a list of the worst sunscreens, and say about one out of every eight do not block UVA rays which can cause skin damage and skin cancer.
Critics of the research using mice and retinyl palmitate combined with ultraviolet exposure say the results of the animal study can’t yet be generalized to humans. They also say the study used retinyl palmitate only, but in sunscreen it is blended with other chemicals so the effects are different.
If you want to read the whole study, it is in PDF format on the National Institutes of Health website. The title is “NTP Technical Report On The Photococarcinogenesis Study of Retinoic Acid and Retinyl Palmitate.”