FAQ: sunscreen

Mostly gone are the days when beachgoers and backyard sun worshippers slathered baby oil all over themselves to get a deep burn, er, tan. Today, people are more interested in protecting their skin from the sun's harmful rays than in soaking them up, and there are more sunscreens than ever that promise to do it. The following guidelines will tell you more.

No. If you want optimal sun protection, you have to search the ingredient lists. Sunscreens these days have gotten pretty sophisticated. Beyond their SPF (sun protection factor) ratings, which suggest how much longer you can stay out in the sun without burning than you could without sunscreen, many claim to be waterproof (though most swimmers know better) and sweatproof.

More importantly, many labels now sport the words "broad spectrum," meaning the sunscreen claims to block both the short-wave UVB rays that cause sunburn and the UVA rays that penetrate the surface of the skin, damaging collagen and elastin fibres and contributing to wrinkles and, possibly, skin cancer.But how effective are these products? According to an analysis conducted by the US organization the Environmental Working Group, 18 percent of sunscreens analyzed that claimed broad-spectrum coverage provided poor UVA protection. According to the analysis, for the best protection against UVA rays, you should look for any one of the following four ingredients.

• Avobenzone (also known as Parsol 1789).
• Mexoryl SX (it's been used for years in Canada and Europe).
• Zinc oxide.
• Titanium dioxide.

If your sunscreen contains avobenzone, you should know that this ingredient breaks down quickly in the sun, so products that rely on it for UVA protection should also contain a stabilizer like Helioplex, Active Photo Barrier Complex, Dermaplex, SunSure or AvoTriplex.

Among the products that met the stringent criteria of the Environmental Working Group were:

• UV Natural Sunscreen.
• Sport (SPF 30+).
• Vanicream Sunscreen, Sport (SPF 35).
• Hawaiian Tropic Baby Faces Sunblock (SPF 60+).
• Blue Lizard Australian Suncream, Sensitive Skin (SPF 30).

It's also critical to apply sunscreen liberally — much more liberally than you probably do. Experts recommend using a shot glass of sunscreen every time you slather it on.

Some people justify soaking up sun with the fact that sunshine prompts the body to make vitamin D. But that logic doesn't pass muster. The truth is that most of us get enough vitamin D during everyday activities like walking to the post office or even driving, assuming we aren't wearing sunscreen.

While the health benefits of vitamin D are well established, the downsides of significant sun exposure far outweigh any upside.

No. Sunscreens with an SPF over 30 provide almost no more protection than you get with an SPF 30 product.

Extracts from a tropical fern called Polypodium leucotomos have antioxidant properties that seem to help protect the skin from sun damage when taken orally. Sold in Europe for two decades, the pills recently became available in Canada and the United States under the brand name Heliocare.