The SPF debate: Could your sunscreen lead to skin cancer?

Even though it’s officially autumn by the calendar, here in Miami, the sunshine never ceases. While we slather on the SPF to block out the sun’s damaging rays, are we doing ourselves more harm than good?

According to the “2013 Sunscreen Guide” published by the Environmental Working Group (EWG), a watchdog organization dedicated to environmental health research and advocacy, certain ingredients in over-the-counter sunscreens could pose serious health risks.

The EWG reports that oxybenzone, found in 80 percent of chemical sunscreens, tops its list of most questionable sunscreen ingredients used in the U.S.

Based on preliminary investigations, including the 2012 study by researchers at the University of Copenhagen’s Department of Growth and Reproduction, scientists have made three major observations that suggest possible side of effects of certain chemical UV filters: “(1) the utilization of sunscreens with UV filters is increasing worldwide; (2) the incidence of the malignant disorder for which sunscreens should protect, malignant melanoma, is rapidly increasing; and (3) an increasing number of experimental studies indicating that several UV filters might have endocrine disruptive effects.”

While the Food and Drug Administration has not formally reviewed claims made by the EWG, many dermatologists and national organizations are not completely convinced, of either argument.

Dr. James M. Grichnik, director of the Melanoma Program at Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine and a professor of dermatology and cutaneous surgery, prefers physical blockers based on zinc or titanium oxide.

“I particularly now like the stick sunscreens that are based on zinc or titanium oxide that you can basically more or less paint the stripe and smooth it into the skin,” he said. “You can keep those in your pocket, they don’t spill, they’re convenient, they work pretty well, and the physical blockers tend to last longer.”

Aveeno and Neutrogena are two such brands that carry zinc- and titanium-oxide-based stick sunscreens.

According to Grichnik, we’ve been using zinc oxide and titanium oxide in our daily lives for decades, from diaper rash cream to food whitening powders.

“So theoretically, they have decent safety profiles,” he said.

Regarding the studies and skepticism of the true “safety” of certain sunscreen ingredients, Grichnik admits he has his doubts.

“I have my suspicions as well, and that’s why I really prefer the zinc and the titanium. I think that we don’t have any data that I’m aware of that suggests a real problem at this point, but I think it is rational to assume that some of these products may not be as good as other, and that’s why I definitely prefer the physical blockers,” he said.

The American Academy of Dermatology is steadfast it its support of SPF.

“Scientific evidence supports the benefits of using sunscreen to minimize short-term and long-term damage to the skin from the sun’s rays. Preventing skin cancer and sunburn outweigh any unproven concerns of toxicity or human health hazard from ingredients in sunscreens,” explains their website.

Grichnik agrees with the AAD.

“There’s very good data that wearing sunscreen is better than not wearing sunscreen, as far as moles and melanoma and skin cancer and all that is concerned. And photo-aging,” he added.

While this debate continues in research laboratories and scientific discussions around the world, the FDA has published new regulations for sunscreen product labels as of May 2013. When stocking up on your summer SPF, be on the lookout for these key terms and phrases.

  • “Broad spectrum” claims must be backed by testing. The new rules will make it clear to consumers whether sunscreens are “broad spectrum,” meaning they protect against both UVB and UVA rays. All sunscreen products protect against UVB rays, which are the main cause of sunburn. But UVA rays also contribute to skin cancer and premature aging. Now, only products that pass a test can be labeled “broad spectrum.”
  • Low SPFs must include a warning. Sunscreens with an SPF lower than 15 must now also include a warning. It reads: “Skin Cancer/Skin Aging Alert: Spending time in the sun increases your risk of skin cancer and early skin aging. This product has been shown only to help prevent sunburn, not skin cancer or early skin aging.” This same warning must appear on sunscreens that are not broad spectrum.
  • “Water resistant” does not mean “waterproof.” No sunscreens are waterproof or “sweatproof” and manufacturers are no longer allowed to claim that they are. If a product’s front label makes claims of being water resistant, it must specify whether it lasts for 40 minutes or 80 minutes while swimming or sweating.
  • Products can’t over-promise. Sunscreens may not claim instant protection or protection for more than 2 hours without reapplying. They may not use the term “sunblock.”

(Source: FDA via American Cancer Society, 2013.)

If you’re still having reservations over SPF, according to Grichnik, there are two key factors to sun protection before sunscreen even enters the picture.

  1. Limit sun exposure: Get out early or save it for later. Grichnik recommends accomplish your outdoor tasks for the early morning or evening, saving indoor activities for the middle of the day when the sun’s damaging rays are strongest. “My key issue is know the time of day. Basically, the mutagenic rays are lower at the beginning of the day and the end of the day. In fact, about 75 percent of all mutagenic rays hit the earth during the 4 hour period in the middle of the day, so if you can avoid that time you can avoid a lot of mutagenic rays,” he said.
  2. Dress to protect: “You know, people in the desert don’t run around wearing bikinis and swim trunks, they actually wear clothing that covers them up and reflects the sun away from their skin,” Grichnik said. “We’ve kind of gotten away from that, but to the extent of which we can, we really should be wearing clothing, you know that’s protective, and that certainly is really the easiest form of sun screen protection, is basically putting on a tight-weave shirt, and wearing a hat and putting on that can control a lot of the blocking for you.”

However you choose to do it, protection is key.

“Anybody from any race can get melanoma and skin cancer, so it’s important for everyone to pay attention,” Grichnik urges.