The Exchange

Commentary and Observations from
the Medical Front Lines

Controversies in Sunscreen – An Update

Controversies in Sunscreen – An Update

It is well established that too much ultraviolet radiation from the sun can damage the DNA in your skin cells, which can lead to premature aging and skin cancer. In the United States, more than 9500 people are diagnosed with skin cancer every day, and at least 1 in 5 Americans will develop skin cancer by age 70.

In January 2020, the Journal of the American Medical Association published a pilot study showing that the chemicals used in sunscreen have a potential for high systemic absorption. This led the FDA to call for further industry testing of systemic exposure to sunscreen ingredients on health and safety—especially with chronic use.

Because of associated toxicity in marine ecosystems, 2 common sunscreen ingredients—oxybenzone (BP-3) and octinoxate (OMC)—were recently banned in Key West and Hawaii. However, this does not necessarily mean that the ingredients are detrimental to human health, and more research and assessment is required to determine their impact on humans. In a systematic review of 29 studies, it was shown that an elevated systemic level of BP-3 had no adverse effect on several health factors, including male and female fertility, female reproductive hormone levels, adiposity, fetal growth, children's neurodevelopment, and sexual maturation. The same review showed that systemic absorption of OMC did not impact thyroid and reproductive hormone levels. Thus, there was no causal relationship found between elevated systemic levels of BP-3 or OMC and negative health impact. Well-designed trials focused on long-term risk of elevated systemic levels and chronic exposure to these ingredients are still needed to fully evaluate their health and safety impacts.

Despite the concern over these ingredients, the facts are that skin cancer is a real concern and sunscreen use has recognized public health benefits; the FDA urges Americans to use sunscreen in conjunction with other sun protective measures, such as sun protective clothing. For those hesitant to use sunscreen with BP-3 and OMC, a mineral-based sunscreen containing zinc and/or titanium dioxide seems to be a safe alternative.

References

Filed under: Dermatology

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