(NaturalNews) Common commercial skin care products may increase users' risk of contracting skin cancer, according to a paper by researchers from Rutgers University and published in the Journal of Investigative Dermatology.
Researchers had originally been planning to study whether topically applied caffeine could reduce people's risk of skin cancer.
"We sort of got into this by accident," researcher Allan Conney said. "We wanted a safe cream that we could put the caffeine into."
The test was to be carried out on albino mice, which are specially bred to be predisposed to skin cancer. In order to simulate the condition of a person who has only recently become aware of the risks of skin cancer but who got lots of sun exposure previously, the researchers bombarded the albino mice with ultraviolet radiation before the study began.
The researchers intended to apply the caffeine by dissolving it into a skin cream, but first wanted to make sure that any cream they used was actually neutral for skin cancer risk. So they applied four commercially available creams to the mice, and discovered that all of them increased the mice's risk of developing skin tumors known as squamous cell carcinoma.
Squamous cell carcinoma is more slow-growing and substantially less lethal than the less common melanoma. Most cases of squamous cell carcinoma can be easily removed without risk to the patient if they are detected and acted on early enough.
The experiment could not determine which ingredients of the skin creams might be causing cancer, but Conney suspects that mineral oil might be responsible, as might sodium laurel sulphate.
"We'd like to understand the mechanism," Conney said. "What is most important is to see whether these moisturizing creams are tumorigenic in people."
Conney said that his lab does not have the capacity to do such studies, but he hopes that other researchers will follow up on his team's findings.