Use moisturizers but avoid excessive sun exposure

Popular moisturizers frequently applied to the skin of laboratory mice appeared to promote the emergence and growth of skin tumors, according to a study by researchers at Rutgers University.

The team used four brands of moisturizers to test whether there is a link between the use of such products and cancer. First they shaved off some hair in mice and exposed them to ultraviolet radiation twice a week for 20 weeks, to simulate exposure to the sun. After irradiation, they treated the exposed skin with the moisturizers, five days a week for 17 weeks.

The results showed that mice receiving the moisturizer treatments developed more and larger skin tumors than the untreated mice.

The researchers said their study should indicate the need for epidemiologists to study whether these products can cause tumors in people. Their study does not really prove that because it only evaluated mice … and human skin is different from mouse skin.

The American Cancer Society estimates close to 60,000 people are diagnosed with melanoma each year. Melanoma is the most malignant type of skin cancer and about 8,400 people die from it each year. Incidence of skin cancers is trending upwards, particularly for young women ("More Young Women Getting Melanoma", safetyissues.com).

Some dermatologists warn that moisturizers should not be blamed for skin cancer, saying there is no evidence that it causes such problems in human skin.

Still, there are experts who point out that baby oil, which is widely used in place of tanning oil, enhances the capacity of the skin to absorb sunlight. It is possible that some skin moisturizers have similar properties. They insist that moisturizers increase the skin’s ability to absorb ultraviolet radiation. And, it is absorbed UV light that can induce changes in the skin.

A noted dermatologist believes the study should alert companies to subject their moisturizing creams to tests and assays. The FDA classifies moisturizers as cosmetics, and therefore does not require the stringent safety and efficacy tests imposed on drugs.

He notes that UV radiation already caused damage to the skin of the mice prior to application of the moisturizers. This could be the factor underlying the tumor-enhancing effect of the moisturizers. The creams did not cause the cancers; it was the radiation exposure. But once the cancers had developed, the moisturizers somehow enhanced their growth.

But all the experts did say consumers should not stop using moisturizers. They are necessary, for as people get older their skins become drier.

Safety Tip:

* Avoid excessive sun exposure. It is the exposure to ultraviolet radiation that increases risk of skin cancer.