Sunscreen Ingredient Linked to Endometriosis
Study Ties a Common Ingredient in Sunscreens, Nail Polishes, and Lotions to Endometriosis
"We find it to be a very weak study and quite unconvincing," says Linda Loretz, PhD, director of safety and regulatory toxicology for the Personal Care Products Council, a group that represents the interests of the cosmetics industry.
Loretz points out that researchers had no information about whether the women used sunscreen or how much they used, which makes it impossible to know how they were exposed to the chemicals.
"I don't think consumers should be concerned," she says. "I think safe sun practices are much more important."
Women in the study who lived in California had higher benzophenone concentrations in their urine if they were tested during the summer months.
That suggests that sunscreen is playing a role in exposure, says Sonya Lunder, MPH, a senior analyst with the Environmental Working Group (EWG) in Washington, D.C.
A separate study by the CDC also found "higher concentrations in lighter-skinned people and also in the summertime, which points to the role of sunscreen in the measurement in our bodies," Lunder says.
The Environmental Working Group publishes its own guide to sunscreen safety, and they have flagged oxybenzone, a chemical that's found in half of all sunscreens, as an ingredient that people should avoid.
"We have raised concerns about it over the past couple of years as these kinds of studies come out -- our concern level matches up with it," Lunder tells WebMD.
"The studies in people are still pretty small, pretty limited, but they are backed up by a series of laboratory studies finding that this chemical and this whole family of chemicals, really, has estrogenic effects," she says.
In addition to acting like estrogen in the body, Lunder says many people are simply sensitive to oxybenzone and that it can cause skin irritation.
The EWG says safer sunscreens are those that are mineral-based with ingredients zinc oxide or titanium dioxide as natural UV blockers.