A new study published in the Journal of Investigative Dermatology suggests that common moisturizers may increase the rate of tumor formation in mice with an increased risk for skin cancer. As can be imagined, the study has provoked fierce criticism by the manufacturers of creams used in the study.
Study Results
The study was conducted by a team of scientists at Rutgers State University in New Jersey. It concluded that a number of widely used moisturizing creams – Dermabase, Eucerin, Dermovan or Vanicream – applied to the skin of mice who were exposed to UVB rays (to increase their risk for developing skin cancer) increased the rate of tumor formation.
30 mice were irradiated with UVB rays twice weekly for 20 weeks in order to increase their risk for tumor formation. After the end of the radiation period, mice were treated with 100mg of the creams, once daily, 5 days a week for 17 weeks.
The formation and size of tumors were measured throughout the study period. At the end of the study the number of mice with tumors was not statistically different in the treated groups in comparison to the control groups, but there was a significant increase in both the rate of tumor formation and the total number of tumors.
Study Criticized
Scientists from the the manufacturers of the creams have responded with complaints focusing on the way the study was designed, the statistical treatment of the results and the relevance of these findings for humans.
In particular, critics have taken issue with the sample size of 30 mice claiming that it wasn’t large enough to make any relevant conclusions. As well, others complained about the study author’s link to human relevance in trying to compare the model using UVB-pretreated high risk mice as resembling humans who had undergone UV exposure early in life.
What Does This Mean For You?
As with any study, it’s important to consider who conducted the study, it’s design and the interpretation of the results along with the actual results.
In this particular study, cream manufacturers and the study authors are still at odds over the study itself and the results. The study team maintains that they cannot be held responsible for the interpretations of their work by others. Further, industry experts agree that more tests are necessary in order to investigate the human relevance of the work. And, others agree that the UVB-pretreatment of the mice is a poor surrogate for human sun exposure, especially given that mice and humans are not very similar when it comes to skin cancer.
Given all the disagreements and inconclusive study results, a lot of research still needs to be conducted before arriving at any conclusion. Moisturizers deliver significant benefit to skin, especially if you suffer from dry skin. My take – keep using them. And if you’re concerned, check with your physician.
