Recently, an article published in the Journal of the American Medical Association (JAMA) demonstrated that significant amounts of common chemical sunscreens are absorbed into the bloodstream. This finding gained widespread attention and generated a lot of questions from patients and the public about sunscreen safety.
In this study, researchers tested four sunscreen ingredients: avobenzone, oxybenzone, octocrylene and ecamsule. Twenty four (24) healthy volunteers were asked to apply one of these four sunscreens to 75% of their bodies four times per day for four days, and 30 blood samples were collected for 7 days. Researchers found that sunscreen absorption was “significant” for all four sunscreen ingredients. But what constitutes significant? The way that media outlets announced it, you would assume that the levels in the bloodstream were known to be dangerous or harmful. This news was definitely relayed in an alarmist fashion. However, upon close inspection of the article, “significant” in this case means higher than a very low number chosen by the FDA to denote when chemicals need extra testing.
Interestingly, the FDA assumes that chemicals present at concentrations less than 0.5ng/mL in plasma are below the “Threshold of Toxicological Concern.” According to the FDA, the chance of an unknown compound causing cancer when the compound is at levels below 0.5ng/mml in plasma is less than 1 in 100,000 in a single dose. As a result, the FDA decided not to require extra testing and safety studies for compounds expected to be present below this level. In the past, many sunscreens have fallen under that exemption. This article, however, now supports that many chemicals in sunscreen might no longer be exempt from further testing and research. But that this article was published is, in my opinion, actually a good thing. Don’t we want to know more about that with which we are basting ourselves?
Sunscreens are getting ever more popular, and the general populations is no longer using a little sunscreen for only those few days spent on a beach trip. In fact, sunscreen ingredients can now be found in a variety of every day products such as make-up, moisturizers, lip balms, hair spray etc. So besides the use of sunscreen during our hobbies, exercise and recreation, we are now using sunscreens as a part of our go-to daily regime, sometimes without even realizing it.
This JAMA sunscreen study simply proved that certain chemical sunscreens used extensively and frequently are being absorbed at levels higher than the FDA’s limit for when an ingredient doesn’t need safety data. This study is very useful because it prompts the FDA and other public-interest groups to ensure that safety data be collected about chemicals formerly thought to be likely present in miniscule levels. This study is important for helping ensure that we will have more knowledge in the future.
But what do we do now? Well the answer to that is simple, use sunscreen regularly and stay tuned! Sunscreen consumers should be aware that the two major types of sunscreen are “physical blockers” which are zinc oxide or titanium dioxide and “chemical blockers” which include chemicals like those tested in this study. The physical blockers reflect the sun away from the skin, and the chemical blockers absorb UV rays like a sponge, mopping up ultraviolet rays before they can damage the skin. In general, there is good safety data for the physical blockers, but both types have been used for decades with few safety concerns ever arising. Currently, there is a very small amount of data that support that chemical sunscreens might affect certain hormone levels or otherwise be harmful to humans. But most importantly, studies have continuously shown that sunscreen use is associated with lower skin cancer risk and reduced photoaging (looking old because of sun exposure). So even if certain sunscreens might carry certain risks, the known benefits of sunscreen currently outweigh the unknown potential risks of sunscreen use. If someone is nervous about the chemical sunscreens, he or she can always use zinc oxide or titanium dioxide physical blockers instead. The answer seems clear that we should use sunscreen when we are going to be out in the sun a lot.
Alarmist news can scare people into making bad decisions. For now, when you are in the sun, you should keep using sunscreen and sun-protective clothing. And this study should be reassuring rather than alarming. It is reassuring to know that researchers and the FDA are gathering data and conducting studies designed to test our assumptions and keep us safe.
If you or a loved one did not use quite enough sunscreen in the past, consider Premier Dermatology and Mohs Surgery of Atlanta. Dr. Brent Taylor is a fellowship-trained Mohs surgeon, board-certified dermatologist and is certified by the American Board of Venous and Lymphatic Medicine.