Moisturizing lotions such as Eucerin and Dermabase may raise the risk of skin cancer, according to a study that tested the products on mice.
Skin tumors grew faster and in greater numbers in mice that were exposed regularly to ultraviolet light and rubbed with the creams than in nonmoisturized animals, a study released today by the Journal of Investigative Dermatology found. The lotions Dermovan and Vanicream showed similar effects.
Cellular damage caused by ultraviolet light from the sun is linked to about 1 million cases of skin cancer in the U.S. annually, said the study's authors, led by Yao Ping-Lu, a cancer researcher at Rutgers University in New Jersey. Moisturizers, used by many people around the world to protect their skin, should be tested for cancer risk, the study said.
“Further studies are needed to determine the effects of the widespread use of moisturizing creams on the risk of sunlight-induced skin cancer in humans,” the authors concluded.
Mineral oil, a familiar ingredient in skin creams, has been linked to tumor formation, and sodium lauryl sulfate, another common ingredient, has been tied to irritation. The researchers also tested a lotion, prepared for them by Johnson & Johnson, that didn't contain those two ingredients. The cream wasn't linked to an increase in tumor risk or growth, the authors said. Telephone calls to the Rutgers researchers weren't immediately returned.
Vanicream has been used safely for 30 years, said Brian Leary, vice president of marketing for closely held Pharmaceutical Specialties, based in Rochester, Minn., in an e-mailed statement. The number of mice that developed tumors after Vanicream treatment wasn't significantly different from the number that grew cancers in the comparison group, he said.
The company is reviewing the study, which is “of doubtful significance given the small number of samples and statistical methods used,” he said.
In the study, hairless mice were exposed to ultraviolet light twice a week for 20 weeks, which increased their rate of developing tumors. They were then rubbed with skin creams once a day, five days a week, for 17 weeks. In some cases, moisturized mice had twice as many tumors.
The study received funding from the National Institutes of Health.