On May 6, 2019, a study was published in JAMA (https://jamanetwork.com/journals/jama/article-abstract/2733085) questioning the safety of many sunscreens based on systemic absorption. The study was small, consisting of only 24 participants and 4 different sunscreens vehicles: lotions, creams, and sprays. Participants were instructed to apply the sunscreens over 75% of their bodies, four times a day for a total of 4 days. During this time, blood samples were obtained from the participants looking at plasma concentrations of avobenzone, oxybenzone, octocrylene, and ecamsule. The results revealed levels exceeding the FDA minimal chemical concentration of 0.5ng/ml. Per FDA guidelines, any active ingredient which achieves systemic absorption above this endpoint should undergo additional toxicology assessment to determine safety in regard to birth defects, cancer, etc.
Let’s consider yet another study. In May 2018, The Journal of the American Academy of Dermatology published the outcomes of a study questioning the effectiveness of high SPF sunscreens. (https://www.jaad.org/article/S0190-9622%2817%2932908-0/pdf). In previous years, it had been common practice to not recommend a sunscreen with an SPF >50 due to the understanding additional protection was not provided. The authors of the study challenged this thought by having 199 participants in Vail, Colorado apply a sunscreen of 50 SPF to one side of their face and 100 SPF to the other. Participants then spent about 6 hours in the sun over the course of one day. The results showed more erythema on the side with the SPF 50. The conclusion: higher SPFs actually decrease the risk of sunburn. As a result of this study, the FDA is proposing to raise the maximum SPF labeling from 50+ to 60+.
The question remains: which sunscreen should we use? Until we have the outcome of the FDA investigation, I am advising my patients to stick to sunscreens which only contain zinc oxide or titanium dioxide. These are physical sunblocks. They either reflect or absorb the sun’s rays. They are not systemically absorbed, which means you run the risk of having a nice white glow to your skin. However, with the newer formulations, this effect is less likely. The most common brands I recommend are: Neutrogena Sheer Zinc; Neutrogena Pure and Free Baby; CeraVe Invisible Zinc; Vanicream Sunscreen; Eucerin Sensitive Protect, Blue Lizard Sunscreen Sensitive, and Aveeno Positively Mineral. Currently, I follow the AAD guidelines of recommending at least an SPF 30. I do inform my patients of the Vail study and encourage them to go higher, when possible.
Another consideration is sun protective clothing if this whole sunscreen issue has you confused and concerned. Collibar (https://www.coolibar.com/) has wonderful clothing options for the whole family and my recommendation for hats with UPF: Wallaroo Hat Company (https://wallaroohats.com/).
Finally, if you are concerned about the impact your sunscreen choices have on our environment, then choose products containing non-nano zinc and non-nano titanium dioxide (https://thewirecutter.com/reviews/best-reef-safe-sunscreen/) also making sure to avoid oxybenzone and parabens.
It is important to note: skin cancer is the most common malignancy in the United States. It is estimated, 1 in 5 Americans will develop skin cancer in their lifetime. The current rate is 9,500 people diagnosed daily. Of the most common types of cancer, melanoma is the only one which continues to increase in incidence. The AAD estimates, 192,310 Americans will be diagnosed with melanoma this year. Therefore, sun protection is still the best option. I never advise my patients to just stay out of the sun. I believe life is meant to be lived, and everything in life should be enjoyed in moderation. Therefore, apply your sunscreen, wear your hats and enjoy your summer!