Image: A variety of sunscreens
NBC News Channel
Many people think SPF fully protects against sun damage, but most formulas only protect against UVB rays. There's no guarantee a product provides protection against UVA.
By
msnbc.com contributor
updated 5/3/2010 8:34:18 AM ET 2010-05-03T12:34:18

Amy Bass, a Texas mother of a 12-year-old boy and twin 5-year-old girls, is careful about slathering her children with sunscreen. The problem is, she can’t tell the difference between brands, taking it on faith that all sunblocks are created equally.

“I just grab whatever’s available,” says 45-year-old Bass, of San Antonio. “I look at my girls and they have such perfect skin and I’d like them to have that forever.”

What Bass and many other consumers don't realize is that while most sunscreens help prevent sunburn, many don’t provide effective protection against skin damage from ultraviolet A rays, which make up 95 percent of the UV spectrum. Some new sunscreen formulas protect against UVA, but there have been some worries about ingredient safety . So, consumers must sort through a maze of misleading claims and products that vary widely in their effectiveness.

Sunburn is caused by ultraviolet B rays, which are stronger at midday and in the summer. However, UVA rays can penetrate glass and are the same strength all year, all day long. Both types of rays contribute to wrinkling, freckling, hyper-pigmentation and skin cancer.

The federal Food and Drug Administration has been promising for more than 30 years to set standards for sunscreen performance and label claims, but hasn’t yet. Some dermatologists are frustrated over the lack of reliable guidelines.

Age-defying tips: Show them you still got it!“For sunscreen to be really effective in preventing skin cancer, it has to provide broad-spectrum coverage,” says Dr. Henry Lim, chairman of dermatology at Henry Ford Hospital in Detroit. “The U.S. is the only industrialized country with no guidelines for UVA protection, so consumers here have no way of knowing.”

Providing some guidelines would be the most helpful thing the FDA could do for consumers, Lim says. But, he adds, “I’m not holding my breath.”

A spokeswoman for the FDA now says its long-awaited sunscreen recommendations will be released in October 2010. That leaves one more hot, sunny summer to hope the sunblock you're slathering on really works.

SPF is ‘very misleading’
The guidelines can’t come soon enough. A recent study in the Archives of Dermatology revealed that more than 2 million people in the U.S. develop non-melanoma skin cancers every year, a more than 300 percent increase in skin cancer incidence since 1994, when rates were last estimated. Most of those cases are sun-related, according to the American Cancer Society. 

Meanwhile, consumer groups are trying to fill the void. According to the Environmental Working Group, a non-profit organization that rates the safety and effectiveness of 1,700 sunscreen brands each year, three out of five sunscreen formulas did not provide the protection promised on the label.

“People are used to just picking this stuff up,” says Sonia Lunder, a senior analyst in the Toxics Research Group at EWG. “We’ve lifted the veil on this idea that there are sunscreens that are ‘all day’ and ‘waterproof’ and ‘sweat proof.’ There aren’t.”

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Right now, the only claim consumers can rely on with any degree of certainty is SPF, or Sun Protection Factor. But most people don’t fully understand what SPF numbers mean — and don’t mean.

“SPF is very misleading,” says dermatologist Dr. James Spencer, of St. Petersburg, Fla. “If I were a logical consumer, I would think that SPF 30 is twice as good as SPF 15. But SPF 15 blocks 94 percent of UVB rays. SPF 30 blocks 97 percent. Past 30, there isn’t much additional benefit to be had,” he says. “It may not be the best measurement, but the FDA has chosen to keep it.”

The danger is that people may think they are getting exponentially more protection from very high SPF products, which may cause them to stay out in the sun longer. Proposed FDA regulations will make 50 the highest SPF available.

People may also think SPF fully protects against sun damage, but it really only measures UVB protection. There’s no guarantee a product provides equivalent, or even any, protection against UVA rays. Many people don’t even know they need it.

“We’ve done a great job of getting out the message to wear sunscreen and stay out of the noonday sun, but the public didn’t get the UVA message at all,” says San Francisco dermatologist Dr. Richard Glogau. Glogau says he and his staff “talk ‘til we’re blue in the face” trying to get patients to understand that they need to take precautions to protect themselves against UVA rays.

Jimmy Cravello, an avid fisherman from Natural Bridge Station, Va., is typical.  “I like to get a base tan or burn before I start using sunscreen,” he says.

Under proposed FDA regulations, a four-star rating system for UVA protection will be added alongside SPF. Spencer and other dermatologists believe a star system will go a long way toward educating consumers about the need for UVA protection, as well as drive manufacturers to make better products.

“No one’s going to want to have the product that has no stars,” he says.

Until then, the only way for consumers to judge UVA protection is to read the fine print, which is no easy task.

What to look for
Sunscreen ingredients fall into two basic categories:

  • Physical blockers, which work by deflecting sunlight.

Titanium dioxide and zinc oxide are very effective physical blockers. These minerals work by deflecting sunlight off skin. In high enough concentrations, (7 percent and up) they provide effective protection against both UVA and UVB rays. 

There is one caveat. High concentrations of these physical blockers tend to leave a white film on skin, so many manufacturers use engineered nanoparticles to make them invisible. The jury is still out on whether these particles are safe, but one thing is certain — there’s no labeling requirement for them, so you might not know they're there.

Friends of the Earth, one group that has cited health and environmental concerns about nanoparticles, publishes a list of nano-free sunscreens. Apart from that, the only way to tell if your sunscreen contains nanoparticles is to call the manufacturer, or guess. If it has a lot of zinc oxide or titanium dioxide and rubs in clear, yes would be a good guess.

  • Chemical blockers, which work by absorbing sunlight, breaking it down and releasing it.

Chemical blockers vary in how much UVA and UVB protection they provide. The irony is that in the process of breaking down sunlight, the chemicals also break down, so they must be combined with stabilizing ingredients in order to remain effective for longer than 30-60 minutes.

Oxybenzone is perhaps the most widely used chemical blocker, but it breaks down easily and blocks only part of the UVA spectrum. There are some concerns about the chemical, which is widely found in human urine and has been associated with low birth weight baby girls in mothers with high concentrations in their bodies. However,its health risks are still unclear.

Avobenzone, also known as parsol 1789, is a better choice. It’s a good UVB blocker, and provides the most comprehensive UVA coverage. However, it still needs to be combined with a stabilizer such as octocrylene to prevent breakdown. Newer patented formulas, such as Neutrogena’s Helioplex, appear to have stabilized avobenzone to the point where it can last 4 to 5 hours, only requiring reapplication if the wearer sweats heavily or take a swim.

Dermatologists cite Anthelios with mexoryl, a proprietary formula from French manufacturer LaRoche-Posay as perhaps the best sunscreen of all. But at around $30 a bottle, the price may give some consumers pause.

However, you’ll use less because it lasts longer, says Dr. Spencer. “$20-$30 for not getting cancer doesn’t sound unreasonable to me,” he says.

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