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The pros and cons of sunscreen

Sunny skies
Sunny skies

Jill Colton, staff writer

June 19, 2010 — The Weather Network spoke to Dr. Cheryl Rosen, national director of the Canadian Dermatology Association's Sun Awareness Program and head of the Division of Dermatology at Toronto Western Hospital to learn about the ABC's of sun block.

Sunny day in Ontario
Sunny day in Ontario

Now that the summer season is almost upon us, it's high time for sun lovers. And with the heat, comes the rush of people purchasing sunscreen. But purchasing your sun protection isn't so simple these days. It seems there are some complications.

There have been quite a few articles published recently, questioning the validity of sunscreen, and whether or not it actually provides adequate protection against the sun's harmful rays.

The Weather Network spoke to Dr. Cheryl Rosen, national director of the Canadian Dermatology Association's Sun Awareness Program and head of the Division of Dermatology at Toronto Western Hospital to get a better understanding when it comes to sun block.


Dr. Rosen says that without a doubt, the biggest mistake Canadians make with sunscreen is that they simply don't wear it. To further emphasize the point she says, “We've had studies done from across the country that show a good chunk of people don't wear sunscreen.” And what's the reasoning behind this? She believes vanity plays a big role. “There's still a cultural preference for a tan among many people -- they still think this looks good.”


Often recognized as the 'sunshine vitamin,' it's an important ingredient in preventing cancer as well as heart disease, osteoporosis, multiple sclerosis and even depression. According to the University of Calgary research, 97 percent of Canadians are vitamin D deficient at some point in the year. The Canadian Cancer Society now recommends 1,000 IU per day for all Canadians.

With this in mind, wouldn't the natural solution to getting more vitamin D be soaking up the sun? Well, according to Dr. Rosen the most effective way to increase your vitamin D intake is to take it as a pill. “Because then you don't have to worry about damaging your DNA causing skin cancer. And, in Canada, in the winter, you cannot make vitamin D from the sun.”

Another issue is that it's very individual, meaning that everyone's ability to produce vitamin D can differ from person to person based on various factors such as your skin type, colour, age, amount of sun, season, latitude, etc. Dr. Rosen doesn't suggest you go out without your sunscreen (in order to soak up as much vitamin D as possible) because you may not realize how much time you're actually spending in the sun.


The sun protection factor can be a tricky one. The SPF is the laboratory measure of the effectiveness of sunscreen — basically the higher the number, the more protection it offers against UVB rays. It's also the sunburn fighter in sun block.

Dr. Rosen says that the amount of sunscreen used is very important when it comes to getting the most out of SPF. She explains, “If you use a bottle that's labelled SPF 30 and you put on very thin layer, you won't get SPF 30 protection against sun burn.” She continues, “With standardized tests in labs, they put on a certain specific amount when they do this kind of testing, and people don't necessarily use that much regularly.” And for those who burn easily (and don't tan) it's important for them to choose sunscreens with a very high SPF so they don't burn their skin.

Make sure you have eye protection!
Make sure you have eye protection!


So is there a magical amount of sunscreen needed to protect yourself? Again, it depends on the individual and your skin type. However, Dr. Rosen doesn't necessarily think there's an exact way for the average person to determine how much sunscreen is the perfect amount. Utlimately, she says, “You just have to have to do a good job covering the sunscreen over your skin and it can't be too thin.” Basically it comes down to using common sense.


“Certainly, if you're swimming or sweating a lot, and exercising heavily, then it's important to reapply.” But what about those that aren't doing anything particularly physical? She says, “We're not really sure of the answer to this -- but it really depends on your degree of activity.”

There is also the school of belief that it's good to reapply sunscreen 20 minutes after your first application because you may not have done the best job the first time around, and you might have forgotten smaller areas such as your ears and neck. “I generally suggest that in the summer, people put it on in the morning -- you brush your teeth, you put on your sunscreen, because people never know what they're going to wind up doing during the day.”


Dr. Rosen says that both UVA and UVB rays are harmful to the skin and damage DNA, but they have different properties to them. When it comes to sunscreen, “The SPF tells you primarily about the UVB, this is a thousand times more able to cause sunburn then UVA.”.

The term 'broad spectrum' refers to UVA protection, “It's hard to find a sunscreen in Canada now, that doesn't say broad spectrum.” However, they haven't yet come up with a way to find a standardized test for ultra-violet protection, there are currently several ways to measure this.


The Environmental Working Group (U.S.) recently released their fourth annual Sunscreen Guide -- it found that many sunscreens contain potentially hazardous chemicals. One being Benzylphenol. According to Dr. Rosen, “The chemical compound has been studied and it's been found to be absorbed (to a small extent) through the skin, and some people excrete it through urine. Other studies show that in rats it makes the uterus increase in size...but when they looked at human beings, they did not find any change in the hormonal levels they assessed. As far as we know....we have not found, in terms of clinical use, documented problems from the usage of Benzylphenol.”

However, Dr. Rosen says Canadian and American manufacturers use different ingredients in sunscreen. Therefore, it can be very important to check the labels and to purchase Canadian-made sun block. “For instance, we have two ingredients that are patented by LÓreal, here we can use them, and in the U.S. they can't really....and this is because Americans have fewer approved ingredients...our products are not exactly the same.”


Despites the negatives, at the end of the day, is sunscreen really the best option for us? Dr. Rosen seems to think so. “We talk about a lot of other methods of sun protection such as hats, clothing, seeking shades, etc. but the truth is, people are going to be out all day long, with their skin uncovered. Sunscreens have been proven to prevent DNA damage, wrinkling, and cold-sores. And so they're the best bet; sunscreens are the best we've got.”

You can find out more information about the Canadian Dermatology Association's recommended sunscreens by visiting their website.

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