Many sunscreens not as effective as they claim, study finds

As summer unofficially kicks off this Victoria Day weekend, it may be time to start re-thinking your sunscreen:according to a new report, manyof them aren't as effective as you might think.

Out of 34 suncreen products tested by Consumer Reports (most of which were American brands), nearlya thirdfell short of the claims on their labels. Eleven of the products delivered anywhere from 16 to 70 per cent less SPF protection than promised.

"It's quite surprising, giventhat sunscreens are highly regulated in both Canada and U.S.," Dr. Sonya Cook, adermatologist and lecturer at the University of Toronto, told Metro Morning guest host David Common.

The study tested for protection against both UVBradiation, which causes sunburns and contributes to skin cancer, and UVA radiation, which causes the skin to tan and leads to wrinkling and aging.

It found that "natural" or mineral sunscreens, whichcontainonly titanium dioxide orzinc oxide as active ingredients, were less effective than chemical sunscreens, which use chemical ingredients such asavobenzone. Of the five natural sunscreens tested, none made the list of 15 recommended products.

Sunscreen tips

Whatever sunscreen you decide to use, Cook recommends checking the expiry date on the label before lathering it onandif you can't find the expiry date, then toss it, she says.

"I thinkit's a good idea every year, do a little Spring cleaning of your sunscreens, and toss out the ones from last year and start fresh," she suggests.

Cook also recommends looking for products that providebroad-spectrum protectionagainst both UVA and UVB rays and which have an SPF ofleast 30. She adds thatcreams andlotions tend to providebetter coverage than sprays or liquids.

She also says that sunscreen should be your "last line of defence" against thesun's harmful rays, and advises wearing sunglasses, hats andsun-protective clothing. You should alsoavoid being insun during itspeak hours of11 a.m. to 4 p.m.but if that's not possible, then Cook advisesapplying lots of sunscreen on exposed areas.