Sunscreen: Friend or Foe?
by Dr. Lauren Oldziej
There are many debates about sunscreen these days, so I’m here to help distinguish facts from misinformation!
There are two types of ultraviolet (UV) radiation released by the sun, UVA and UVB. Most modern sunscreens offer broad-spectrum protection against both UVA and UVB rays. UVA rays penetrate deeply into the skin, accelerating aging and wrinkling, while UVB rays cause sunburn and promote the development of skin cancer.
Sunscreens contain active chemicals that work by absorbing UV rays (chemical blockers) or by reflecting them (physical blockers). Below are the most common chemicals used in the US:
Chemical blockers: Avobenzone, oxybenzone, octinoxate, homosalate, octisalate, octocrylene, ensulizole, ecamsule
Physical blockers: Zinc oxide, titanium dioxide
In 2021, the FDA reviewed sixteen of the chemicals currently used in US sunscreens, of which only zinc oxide and titanium dioxide were “generally recognized as safe and effective.” Aminobenzoic (PABA) and trolamine salicylate were confirmed to be unsafe, while twelve other UV filters lack sufficient safety data to confirm their safety or effectiveness (but are still allowed to be sold in US products).
The primary health concern associated with chemical UV filters is their potential to be absorbed by the body and interfere with the endocrine system, which regulates our hormones. This evidence is based on rat studies where these animals were fed high doses of these ingredients, whereas our exposure is through the skin and in smaller amounts. There is limited and inconclusive data on humans, thus more controlled and long-term studies are needed to determine toxicity and adverse effects.
Evidence does suggest that UV filters are rapidly absorbed by the skin. It’s important to note that human exposure to these UV filters doesn’t only come from sunscreen, but also cosmetics, household products, and plastics. One study found oxybenzone in all tissue samples in a Danish children, indicating year-round exposure independent of sunscreen use.
I’m providing you with all this information to help you make an informed decision on which sunscreen products to use. We know that regular sunscreen use reduces the risk of all forms of skin cancer, so it’s an integral part of protecting our skin against the sun. If you’re considering “natural” sunscreen, be weary that these products use plant oils or extracts that have minimal scientifically proven UV protection. DIY recipes that can be found online have insufficient SPF values and inconsistent protection.
If you’re concerned about chemical filters (and rightfully so), zinc oxide and titanium dioxide provide excellent broad-spectrum protection, and have been validated by the FDA. Zinc oxide provides broader UVA protection than titanium dioxide, with the two often combined for optimal coverage.
I recommend exploring the Environmental Working Group’s Verified Sunscreens list, where they review and verify each ingredient ingredient in sunscreen products - https://www.ewg.org/sunscreen/about-the-sunscreens/
Here are some friendly reminders:
Select a sunscreen with SPF 30 or higher with broad-spectrum protection to guard against both UVA and UVB rays.
Apply a generous amount of sunscreen. Adults need about 1 ounce (a shot glass full) to cover the entire body.
Apply at least 15 minutes before sun exposure to allow time for the sunscreen to bind to your skin. Reapply regularly every 2 hours, even on cloudy days.
Don’t forget to apply sunscreen on the ears, back of the neck, tops of the feet, hands, and scalp.
When layering with other products, sunscreen goes on after moisturizer, but before makeup.
Combine sunscreen with other sun protection measures, like wearing protective clothing, hats, and sunglasses, and seeking shade during peak sun hours in midday.
The bottom line, proper sunscreen use is a key step in preventing sunburn, premature aging, and skin cancer. Make it a daily habit, apply it generously, and don’t forget to reapply—your skin will thank you for it!
Wishing you a wonderful summer filled with fun, sun, and plenty of sunscreen!
Have additional questions? Schedule a visit with myself or one of the other team members here!
See you in clinic,
Dr. Lauren
References
Burnett M, Wang S. (2011). Current sunscreen controversies: a critical review. Photodermatology, Photoimmunology & Photomedicine. 27(2):58-67. doi: 10.1111/j.1600-0781.2011.00557.x
Fivenson D, Sabzevari N, et al. (2020). Sunscreens: UV filters to protect us: Part 2-Increasing awareness of UV filters and their potential toxicities to us and our environment. Int J Womens Dermatol. 7(1):45-69. doi: 10.1016/j.ijwd.2020.08.008.
Krause M, Kli A, et al. (2012). Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters. Int J of Androl. 35(3):424-436. https://doi.org/10.1111/j.1365-2605.2012.01280.x
Maslin D. (2014). Do sunscreens protect us? Int J of Dermol. 53(11):1319-1323. https://doi.org/10.1111/ijd.12606
Sabzevari N, Qiblawi S, Norton SA, Fivenson D. (2021). Sunscreens: UV filters to protect us: Part 1: Changing regulations and choices for optimal sun protection. Int J Womens Dermatol. 7(1):28-44. doi: 10.1016/j.ijwd.2020.05.017. PMID: 33537394; PMCID: PMC7838247.