MSNBC Health says slathering on shiny lip glosses that don't have SPF in them could make the sun's rays hit harder and increase the risk of skin cancer. The story says:
"[Shiny] lip glosses can make more of the light
rays penetrate directly through the skin instead of getting reflected
off of the skin's surface," says Dr. Christine Brown, a dermatologist
at Baylor University Medical Center in Dallas. (You're covered,
however, if you wear lip gloss with SPF.)
At
worst, say some dermatologists, the resulting sun damage can lead to
potentially fatal forms of skin cancer. An estimated 3,500 new cases of
skin cancer of the lips are diagnosed each year, and 90 percent of
those cancers are squamous cell carcinoma. While that form of cancer
isn't usually particularly serious, it can be more aggressive on the
lips than on other parts of the skin. If left untreated, it can cause
disfigurement, and in very few cases, it can spread to other organs and
become deadly.
