How important is it to use sunscreen?
The skin remembers built-up damage from sun exposure so it is important to start ultraviolet (UV) radiation protection young and to keep it up as you get older, when your immune system is more vulnerable, dermatologist Amanda Oakley says.
“Skin cancers are very prevalent and the population is ageing, and as most skin cancers occur over the age of 65 and now 65-year-olds are regularly living until 95, and the epidemic of skin cancer has become horrendous, especially in white-skinned people,” Oakley says.
“You can go outside for just a few minutes when you’re older and think ‘that’s all right, I didn’t get burned’. But what’s happened is the long-wave ultraviolet has increased that immune suppressant effect of age. And you might have got a dormant skin cancer and then it sprouts because of just those few minutes outdoors and your age.”
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Don’t let any dip in temperatures or clouds fool you – UV radiation is about the angle of the sun. You can find the UV index on the MetService app.
“Between the hours of say 10am and 4pm, there’s enough ultraviolet to damage our skin all year round, but especially from October through ‘til April.”
Melanoma NZ says most skin cancers are caused by exposure to UV radiation and New Zealand has one of the highest rates of melanoma in the world.
What are the two main types of sunscreen?
The two general groups of active ingredients in sunscreens are physical (sometimes called mineral) and chemical.
Consumer NZ’s Belinda Castles says the physical sunscreens contain zinc oxide and/or titanium dioxide minerals, which create a barrier to reflect UV radiation away from your skin, but it is now believed they can also absorb UV radiation, like chemical sunscreens.
Chemical sunscreens work by penetrating into the skin, absorbing UV rays and converting them into heat and releasing it from your body.
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But there’s no difference that we know of in terms of efficacy between these two types, Castles says.
“We do have concerns that there’s no regular testing requirement, so a sunscreen might have been tested several years ago, but at least they’ve been tested at some stage to show that they meet their claims.”
So are more expensive sunscreens worth it?
Your choice of sunscreen goes back to whether you will actually use it or not, Oakley says.
“The cost might be more of a marketing ploy [rather] than an effectiveness of the product ... but it may be more expensive to produce something that people find cosmetically acceptable.
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“There are products which are thicker and thinner and stickier. They might resist water better. They might stay where they are better. But the main thing is you have to like it enough to be prepared to use it.”
Consumer NZ’s research of sunscreens did not find evidence of difference in protection between cheaper and more expensive ones, Castles says.
“So often it comes down to the feel of a sunscreen, the brand name, just like anything, the marketing of more expensive products.”
So what should I look out for when buying a sunscreen?
Three main things to look for are “broad spectrum” to protect against UVA and UVB rays, consider the SPF number - 30 or higher offers high or very high protection - and whether you need a water-resistant one if you are going in the water.
Oakley also recommends a smaller packet, which gives you a chance to test out whether you will like putting it on, and will still last you through summer without expiring before you have used it up.
And Melanoma NZ says SPF in your makeup is not enough for effective protection.
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How much should I apply and when?
The effectiveness of protection may be less about what you buy and more about how you use it. Castles says it is important to be liberal in applying it, with adults recommended to apply seven to nine teaspoons for their whole body and face.
“So the recommendation is to apply at least 20 minutes before you go outside to give it time to absorb into your skin and also reapplying it often so that every two hours you’re outside. And also after swimming, or if you’ve been sweating a lot with exercise.”
Studies show people apply only about 20% of what they should to adhere to guidelines, Oakley says.
“And in fact, the first time you put it on in the day, you should put two layers on to make sure you didn’t miss anywhere.”
Finally, it is not enough to just rely on sunscreens for protection, Castles says. Put on suitable clothing when you are going for a swim, a broad-brimmed hat, sunglasses, and seek shade when the UV index climbs or plan your activities around those times.
“Sunscreens wash off, sweat off, rub off and it’s terribly expensive for reapplying sunscreen over and over again,” Oakley says.
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“Whereas if you buy a garment that might be expensive the first time, [but] it can be used many times.”
This article provides general information. For individual health advice, speak to your GP or a qualified professional.
- RNZ
