The U.S. National Cancer Institute — in bold type on an a section added to its web site in June 2010 — admits that there is no evidence that avoiding sunlight or sunbeds actually decreases the risk of skin cancer.

“It is not known if protecting skin from sunlight and other UV radiation decreases the risk of skin cancer,” the NCI writes in an advisory titled “Skin Cancer Prevention.” The article continues, “Sunscreen may help decrease the amount of UV radiation to the skin. One study found that wearing sunscreen can help prevent actinic keratoses, scaly patches of skin that may become squamous cell carcinoma. However, the use of sunscreen has not been proven to lower the risk of melanoma skin cancer.”

The NCI couches its recommendations about sun exposure and UV light with the words “may” and “suggest” — showing that the agency and others continue to blur the line in public health recommendations, encouraging people to avoid UV and mid-day sun even though they do not have cause-and-effect evidence to say that UV “will” cause skin cancer.

“Being exposed to ultraviolet radiation is a risk factor that may increase the risk of skin cancer,” the agency writes in the same advisory. “Studies suggest that being exposed to ultraviolet (UV) radiation and the sensitivity of a person’s skin to UV radiation are risk factors for skin cancer.”

What’s it mean?

“The difference between advising people to avoid sunburn based on what studies suggest and blurring the line to still make it appear that any and all UV exposure is harmful — when evidence does not support that statement — is the wrong way to approach this” Smart Tan Vice President Joseph Levy says. “You keep reading items like this from so many agencies and the inferences all seem to point in the same direction, benefiting the $6 billion chemical sunscreen pharmaceutical market. Still, this article is quite clear: Dermatology leaders need to stop saying point blank that avoiding sun will decrease the risk of cancer. The government does not support that claim.”

To read the NCI advisory click here.