Sunscreen Review

Which sunscreen ingredients protect best?

If the sheer number of sunscreens available isn't confusing enough for consumers, then the large quantities of conflicting information surrounding the topic certainly are. Sunscreens are available in a variety of preparations (sprays, lotions, creams) and potencies (SPFs from 15 to 100), but the SPF number doesn't tell the whole story.

There are two types of skin-damaging ultraviolet (UV) rays: UVB rays, which cause common surface sunburns, and UVA rays, which trigger deeper connective-tissue damage (including skin cancer and the wrinkles and sunspots associated with premature aging). In addition, there are two kinds of skin-damaging UVA rays – short and long. UVA rays are longer (320 to 400 nanometers) and penetrate the skin at deeper levels, causing long-term damage associated with signs of aging and skin cancer. According to the Skin Cancer Foundation, these rays are "present with relatively equal intensity during all daylight hours throughout the year, and can penetrate clouds and glass." UVB rays, on the other hand, are shorter (290 to 320 nanometers) and are responsible for visible damage to the skin in the form of sunburns. Unlike UVA rays, the intensity of UVB rays varies by season, location and time of day. (In the United States, UVB rays are most intense between the hours of 10 AM and 4 PM from April to October.) Experts say a good SPF sunscreen should protect users from both UVA and UVB rays. The best formulas should contain broad-spectrum chemical or physical sunscreens or a combination of the two.

A product's ingredients are directly connected to its level of protection. Physical sunscreens are made with minerals (titanium dioxide and zinc oxide) that form a natural, protective layer on the skin that blocks the sun's harmful rays. Chemical sunscreens (avobenzone, Mexoryl SX and Tinosorb) absorb UV rays. It's important to note that some chemical SPF sunscreens, including the commonly used oxybenzone, can protect only against a portion of UVA waves (those in the lower end of the UVA spectrum). Many sunscreens contain oxybenzone, but they don't contain anything to protect against long-wave UVA. By including oxybenzone, companies are allowed to say their product protects against UVA, but unless it also contains avobenzone, zinc oxide, titanium dioxide or Mexoryl SX, experts say users are not optimally protected against long-wave UVA rays. Mexoryl SX is a highly publicized ingredient that has been used in Canada and Europe since 1993, and it was approved by the Food and Drug Administration (FDA) for use in the U.S. in July 2006. However, sunscreen products containing Mexoryl SX (a trademark of L'Oreal) have been slow to enter the U.S. market. Initially only a handful of products with Mexoryl, all made by L'Oreal-owned companies, were available in the U.S., but the number is growing.

Reviewers and some beauty magazines say Mexoryl SX contains an ideal mix of ingredients for the best possible protection, but Paula Begoun, skin care expert and author of "Don't Go to the Cosmetics Counter Without Me," is skeptical. She agrees that products using Mexoryl SX offer reliable UVA protection, but she says the formulas available are expensive and don't contain many other beneficial ingredients, such as antioxidants. She also says Mexoryl SX doesn't offer the best possible protection. "Although Mexoryl SX is a good UVA sunscreen," she says, "it does not provide the highest level of UVA protection as claimed on the label." Begoun says natural sun-blocking formulas containing titanium dioxide and zinc oxide provide greater levels of protection. The bottom line: Mexoryl SX is an effective broad-spectrum sunscreen, but it's expensive and other options are also viable.

In our quest to identify the most effective sunscreens, we turned to Beautypedia.com, a subscription-based database created by Begoun. She rates sunscreens on how well they protect the user from UVA and UVB rays, as well as on water resistance, fragrance and feel. We found that her website offers the most thorough, credible information. ConsumerReports.org also provides an excellent review in which SPF sunblock brands are tested for their UVA and UVB protection levels. Several beauty and fashion magazines rate sunscreens as part of their annual beauty awards, though their tests are more informal.

Some of the newest sunscreen products use nanotechnology to make formulas that are more aesthetically pleasing. Nano-sized titanium dioxide and zinc oxide particles are much smaller than the typical micronized particles contained in most SPF sunscreens. The smaller particle size allows them to go on more smoothly without leaving a noticeable white cast on the skin. Some consumer advocates warn that nano-size particles can penetrate the skin and are potentially hazardous. However, editors of TheGreenGuide.com, a National Geographic website, say that studies show that these particles cannot penetrate the skin deep enough to be absorbed into the bloodstream, and they are generally trapped in the outer layer of the skin and not absorbed at all. Begoun agrees, pointing out that there is no scientific proof that these sunscreens are absorbed into the skin. She says, "Actually, you wouldn't want that to happen regardless of any potential risk because sunscreen actives need to remain in the surface layers of skin in order to protect it from UV damage."

Other controversial issues: In their sunscreen report, The Environmental Working Group (EWG), a consumer watchdog group that lobbies for more regulation by the Food and Drug Administration (FDA), studied 500 sunscreens and found only 39 that provided acceptable protection. According to the EWG, many SPF sunscreens don't provide adequate UVA protection and contain chemical ingredients that may be harmful to the skin. However, several experts, including the American Academy of Dermatology, have since come forward to say that the EWG's report contains information that is unsubstantiated. Although people continue to debate on both sides, most experts say sun exposure is more harmful than the other possible side effects of some sunscreens and suggest that until further studies are available, consumers should continue to use broad-spectrum sunscreens of all types. However, because of increasing interest in the topic, we have included a section on natural sunscreens (products that use fewer chemicals) for concerned consumers.

 Additionally, some question whether sunscreens trigger vitamin deficiencies. Some experts have suggested that daily sunscreen usage can increase a person's risk of developing a vitamin D deficiency, because the sun is the most readily available source of this nutrient. Dermatologists, however, say sunscreen is necessary to reduce the risk of skin cancer. Ultimately, medical experts say this: Skin cancer is a proven threat -- and the only real way to reduce risk is to limit sun exposure by staying indoors, wearing protective clothing and using broad-spectrum sunscreen. If you're concerned about a deficiency, speak to your doctor. Sunshine aside, Vitamin D is also available in supplements and certain foods. See our report on multivitamins for noteworthy options. Our blog post on the topic also provides further insight into this debate.

Beyond SPF: sunblock labeling

Look at a bottle of sunscreen and you will find words such as SPF, waterproof and UVA protection in flashy type that are supposed to educate you about the product, Here's a short lesson in all things sunscreen to help you decide wisely.

The first is that large number that holds the most real estate on the bottle: the SPF or the sunscreen protection factor. This number is frequently misunderstood. For instance, many people think that an SPF 30 sunscreen offers double the protection of an SPF 15. In actuality, the difference is slight. Experts say SPF 15 blocks 93 percent of rays, while SPF 30 blocks 97 percent. Additionally, SPF ratings higher than 30 don't offer more UV protection, and they let the same 3 percent of UV rays through as SPF 30 sunscreen. However, a higher SPF means you may not have to reapply as often. And to confuse matters even more, SPF only applies to UVB rays. For that reason, it's just as important to look specifically for UVA protection. Ultimately, when it comes to purchasing sunscreen, know that SPF 30 offers adequate protection when extended sun exposure is expected and SPF 15 is suitable for everyday use.

Although the FDA has proposed a new rating system to measure UVA protection in sunscreens, these changes likely won't be seen in mass production until 2012. In the meantime, experts say it's best to check the ingredient list to make sure that your sunscreen contains avobenzone, Mexoryl SX, titanium dioxide or zinc oxide (these last two are more natural sunscreen ingredients), each of which is a key protective ingredient.

Although many sunscreen manufacturers use the terms "waterproof" and "sweat-proof" to describe their products, sunscreens can more accurately be described as water- and sweat-resistant because they need to be reapplied after exercise or contact with water. "Sunblock" also is not a completely accurate term because no product can block all harmful rays.

Finally, you may notice that some sunscreens display logos from the American Cancer Society (ACS). This does not indicate that the ACS has tested or endorses the sunscreen -- the companies pay a royalty fee for the right to display the logo.