Skin moisturizers are usually considered completely safe and healthy products. But a shocking study from Rutgers University suggests that some common moisturizers actually may promote skin cancer and lead to the development of aggressive, fast-growing tumors.
The incidence of non-melanoma skin cancers in the United States has drastically increased in recent years to more than 2 million cases per year, more than all other cancers combined.
“There’s been a lot of speculation about why the incidence is going up,” says the study’s lead author Allan H. Conney, director of the Rutgers’ Susan Lehman Cullman Laboratory for Cancer Research. “It may be because people are going outside more than they used to, wearing less clothes than they used to, or the depletion of the ozone layer. But I think moisturizing creams are also a possible factor.”
Dr. Conney said his work linking skin moisturizers and cancer was a byproduct of unrelated research he was doing on topical caffeine, which has been found to prevent skin cancer. In the course of their work, Conney’s team decided to test the carcinogenic activity of a common skin cream, Dermabase. Because it is unethical to do such tests in humans, they used an animal model of skin cancer: hairless mice which are exposed to UVB radiation early in life to simulate the heavy sun exposure many people receive in childhood. After the mice were pre-treated with UVB radiation, they were treated with topical Dermabase once a day, five days a week for 17 weeks.
The result: an increased rate of skin cancer in mice treated with Dermabase compared to mice not treated with a moisturizer.
Surprised by this finding, Dr. Conney and his team performed new animal tests with Dermabase and three other moisturizers: Eucerin Original Moisturizing Cream, Vanicream, and Dermovan (a wholesale-only product discontinued in 2006). Their study was published in an issue of the “Journal of Investigative Dermatology” and showed that all four moisturizers increased the total number of tumors by the following percentages:
• Dermovan, 95 percent
• Dermabase, 69 percent.
• Vanicream, 58 percent
• Eucerin, 24 percent
The researchers were careful to point out that early-life UVB exposure was the actual cause of the skin cancer in mice and that moisturizer use seemed only to hasten its development. They also pointed out that mouse skin is much thinner and more permeable than human skin, and concluded that more research is needed “to determine the effects of the widespread use of moisturizing creams on the risk of sunlight-induced skin cancer in humans.”
Dr. Conney tells Newsmax Health: “Our studies don’t say anything as to what happens in humans, and I think that’s an important point.” Human studies, he says, “are very badly needed.”
Predictably, moisturizer manufacturers were horrified by Conney’s study and point out that millions of people have used their products for decades with no ill effects. Even Conney says that people who need moisturizers should continue to use them pending further research.
“If people have skin problems that could lead to infection, it’s important for them to use moisturizers,” he says.
If people want to make absolutely sure they are safe, Dr. Conney recommends avoiding two moisturizing ingredients, sodium lauryl sulfate and mineral oil, which may cause inflammation and therefore promote cancer.
In the meantime, Dr. Conney and his team have applied for a government grant for further study.