Everything (Almost) You Should Know About Sunscreen

 selection process for best sunscreens (those offering the most protection with the least risk of harm) enters a new variable: blue light from device screens, which may increase pigmentation and effects of aging on the skin.

At a 2019 sunscreen symposium, “there was unanimous consensus among chemists and FDA personnel there that we do need to start to include blue-light protection into sunscreens going forward,” according to Miami dermatologist Loretta Ciraldo.

That iron oxide is the only sunscreen ingredient offering protection against high-energy visible (HEV) light from device screens adds to the advantages of “mineral”—versus “chemical” — sunscreens, said dermatologist Shari Marchbein at New York University School of Medicine.

While chemical ingredients “don’t do anything” to protect against HEV light, according to Marchbein, other mineral ingredients like zinc oxide provide some protection because of their light-scattering components. Although dermatologists predict a proliferation of blue-light-specific products, for now only a few contain iron oxide, including Elizabeth Arden’s PREVAGE city Smart Broad Spectrum and Murad City Skin Age Defense.

Meanwhile, in interim reports for an updated FDA “Guide to Sunscreens” —promised for January of 2020 and now expected in November—the only two ingredients to receive a  GRASE (generally recognized as safe) rating are titanium dioxide and zinc oxide, both found in mineral sunscreens.

While unlikely, come November, the FDA could  make all chemical sunscreen ingredients illegal.  Another warning in the 2019 FDA “proposed” requirements: to protect sunscreens from excessive heat and direct sun, wrap them in towels or keep them in coolers or in the shade.

Additional sunscreen warnings from about one-third of dermatologists extend to all spray formulations. These include the greater difficulty assessing if and where adequate amounts have been applied as well as the risk of inhalation, especially if sprayed near the mouth.

Chemical sunscreens, however, including ingredients like oxybenzone, receive higher marks for protection from Consumer Reports.  Another advantage: many offer “very water-resistant” protection for 80 minutes—compared to the limit of 40 minutes for most mineral options.

Oxybenzone tops the list of sunscreen-ingredient warnings from the Environmental Working Group.  Among several sunscreen ingredients that can enter the bloodstream and remain in the body for extended periods of time, oxybenzone can disrupt hormones and has been linked to increased risk of endometriosis.

But the EWG reserves its biggest warning for the failure of most sunscreens to protect against UVA rays, which penetrate the skin more deeply and are more difficult to block. UVA rays suppress the immune system, may contribute to skin aging and are associated with higher risk of melanoma.  Zinc oxide does the best job among sunscreen ingredients of protecting against UVA, followed by the chemical avobenzone.

In addition, the EWG warns against high-SPF products, arguing that increased SPF diminishes UVA protection.  For this reason, people who rely on high-SPF sunscreens “may expose themselves to more harmful ultraviolet radiation…people trust these high SPF products too much,” according to the EWG’s Guide to Sunscreens.

Because of FDA restrictions on ingredients and concentrations, U.S. sunscreens offer far less protection against UVA than UVB rays, and this is worse for products with the highest SPF values,” according to the EWG.  For this reason, Europe permits the sale of fewer than half of American products with SPF over 50.

Of UVA-protective ingredients permitted in European sunscreens but not in the U.S., the FDA has allowed Laroche-Posay to use ecamsule (Mexoryl) in one product, “Anthelios SX,” a moisturizer with an SPF of 15 but clearly marked “Mexoryl SX.”  For wider FDA approval, the parent company L’Oreal would need to fund further research, but ecamsule is one of the chemicals absorbed by the body and thus opposed by the EWG.

The EWG also questions the “broad spectrum” claim for many products due to lax standards for using the label.  “One study found that participants who used a poor-quality broad-spectrum sunscreen for two days on a tropical beach got the same UVA exposure as those visiting a tanning salon once.”

Another worry about UVA rays is that they penetrate glass, according to the American Cancer Society, making it important for anyone sitting indoors near sunny windows to reapply sunscreen every two hours—the same as anyone spending time outside.

Blue light—potentially contributing to effects similar to those of UVA rays—may be another reason to wear sunscreen indoors.  While sun is the main source of HEV light, we get a “significant dose” from screens and indoor lighting, according to Marchbein. Blue light may also contribute to cataracts, glaucoma and other eye diseases.

The limited research to date showed blue light caused hyperpigmentation but only in people with darker skin tones. Other evidence suggests that blue light contributes to photoaging, leading to wrinkles and skin laxity.  And, anecdotally, dermatologists report seeing new patterns of hyperpigmentation that may be related to holding cell phones against the cheek.

Waiting for “the majority of sunscreens [to eventually] protect against blue light,” Ciraldo suggests lowering brightness levels on screens to 50% or go to the darker “night shift” setting to help prevent skin damage.

In the end, Marchbein cautions that blue light also provides many benefits — “plays a critical role in maintaining good health… regulates our body’s circadian rhythm…elevates mood and helps memory and cognitive function.”

With no sunscreen excelling in the selection process on best protection with least harm — and all potentially creating the same false security as those with high SPF — the best protection against damaging rays may come from elsewhere: stay indoors as much as possible during peak sun hours from 10am to 4pm and otherwise wear long sleeves and a large hat.

Off-hours, though, enjoy warm, bright sunlight whenever possible.  Allow device screens lights to stay sufficiently bright to enable reading without strain.  And do whatever else it takes to keep from worrying about one more thing.

—Mary Carpenter

Every Tuesday, well-being editor Mary Carpenter delivers health news you can use.

One thought on “Everything (Almost) You Should Know About Sunscreen

  1. Deba Leach says:

    Glad to have advice like this from trusted source.

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