Moisturizers Up Skin Cancer in Mice
4 Commonly Used Moisturizing Creams Promote Tumors in UV-Exposed Mice
Aug. 14, 2008 -- Four commonly used moisturizers promoted skin cancers in mouse studies.
Mice are not men. But the unexpected finding suggests that these -- and perhaps other products -- may not be as safe as they're thought to be.
The moisturizers tested in the study were Dermabase, Dermovan(a wholesale-only product discontinued in 2006), Eucerin Original Moisturizing Cream, and Vanicream.
In a mouse model of sun-related skin cancer, frequent application of each product resulted in more skin tumors and faster tumor growth, says study leader Allan H. Conney, PhD, director of the Susan Lehman Cullman Laboratory for Cancer Research and professor in the school of pharmacy at Rutgers University in Piscataway, N.J.
"This was unexpected. We really did not expect to see the tumor-promoting activity of these creams," Conney tells WebMD.
In fact, Conney and colleagues were getting ready to use one of these moisturizers -- Dermabase -- in human clinical trials of topical caffeine, which prevents skin cancer in animal studies.
"We thought it would be prudent to test Dermabase by itself to see if it had tumor-promoting activity," Conney says. "We did not think it would. But lo and behold, to our surprise we got an increased rate of skin cancer."
This led to new tests of Dermabase and the three other moisturizers, which the Conney team hoped to use in their human study. For these new animal studies, the researchers used hairless mice irradiated with ultraviolet light twice a week for 20 weeks. With no further irradiation, such mice eventually develop skin cancer -- very much like humans overexposed to sunlight early in life.
Five days a week, for 17 weeks, the researchers rubbed moisturizer into the animals' skin. The result:
- Dermabase increased the total number of tumors by 69%.
- Dermovan increased the total number of tumors by 95%.
- Eucerin increased the total number of tumors by 24%.
- Vanicream increased the total number of tumors by 58%.
"The multimillion-dollar question is, what about humans?" Conney asks. "The answer is, we don't know. Our study raises a red flag and points out the need for epidemiologists to take a look at people who use moisturizing creams. And the companies that market these products should take a look at animal models and see if their products promote tumors."