TAGS: Sun Care
A pilot study conducted by the Center for Drug Evaluation and Research, an arm of the US Food and Drug Administration found that several common sunscreen ingredients enter the bloodstream at levels high enough to trigger a government safety investigation. This study was published in JAMA journal also found that these ingredients continued to rise as daily use continued and then remained in the body for at least 24 hours after sunscreen use ended.
The Harmful Chemicals
The four chemicals studied -- avobenzone, oxybenzone, ecamsule and octocrylene -- are part of a dozen that the FDA recently said needed to be researched by manufacturers before they could be considered "generally regarded as safe and effective."
"Studies need to be performed to evaluate this finding and determine whether there are true medical implications to absorption of certain ingredients," said Yale School of Medicine dermatologist Dr. David Leffell, a spokesman for the American Academy of Dermatology. He added that in the meantime, people should "continue to be aggressive about sun protection."
The New Sunscreen Study
The new FDA study enrolled 24 healthy volunteers who were randomly assigned to a spray or lotion sunscreen that contained avobenzone, oxybenzone or octocrylene as ingredients or a crème sunscreen that contained the chemical ecamsule.
The volunteers were asked to put their assigned sunscreen on 75% of their bodies four times each day for four days. Thirty blood samples were taken from each volunteer over seven days.
Of the six people using the ecamsule cream, five had levels of the chemical in their blood considered statistically significant by the end of day one. For the other three chemicals, especially oxybenzone, all of the volunteers showed significant levels after the first day.
"Looking through the results tables of the study, one thing about oxybenzone stood out," Andrews said. "Oxybenzone was absorbed into the body at about 50 to 100 times higher concentration than any of these other three chemicals they tested."
In 2008, the US Centers for Disease Control and Prevention analyzed urine samples collected by a government study and found oxybenzone in 97% of the samples. Since then, studies have shown a potential link between oxybenzone and lower testosterone levels in adolescent boys, hormone changes in men, and shorter pregnancies and disrupted birth weights in babies, but researchers caution about assuming association.
The European Union has mostly replaced oxybenzone in its sunscreen products with newer, more protective substances that block out more of the dangerous UVB and UVA rays. But those newer products have not passed the safety tests needed for FDA approval. So oxybenzone remains in use.
Research Urgently Needed
In an editorial accompanying the new study, former FDA Chairman Dr. Robert Califf assured readers that just because the research found chemical levels "well above the FDA guideline does not mean these ingredients are unsafe."
Califf said next steps would be appropriately designed clinical trials by industry to test safety and determine the optimal dose to prevent skin cancer while balancing risk and benefit. In addition, he said, "an urgent question involves absorption in infants and children, who have different ratios of body surface area to overall size and whose skin may absorb substances at differential rates."
The Personal Care Products Council's statement said the industry has offered "state-of-the-art toxicological safety approaches as alternatives" to the FDA's testing method. "We look forward to our continued work with the FDA to ensure that consumers have access to products containing a broad variety of sunscreen active ingredients," Kowcz said.
While science continues to answer questions about sunscreen, Califf and other experts call for the public to continue to protect their skin from the dangerous rays of the sun.
This study was published in the
medical journal JAMA.
Source: JAMA