Here’s Why You Need To Use SPF All-Year-Round According To A Dermatologist

When it comes to anti-aging and protection from skin cancer, SPF is the be-all and end-all. However, what many don't realise is that SPF is required in your skincare regime every single day rendering it just as important on a day out in the snow as it is on a sunny day at the beach or getting around in and out of your car. 

So, to guide you on your journey to healthy, beautiful, glowing skin, we’ve teamed up with trusted skincare experts La Roche Posay to give us the scoop on all things sun protection. Here, we sit down with Dermatologist Dr. Harriet Cheng to fill us in on everything we need to know about SPF and why it's so important to use it all year round (yes, even in winter). 

Firstly, what is SPF?

SPF stands for sun protection factor. It's an indication of how well a sunscreen protects against ultraviolet (UV) B light. It's an indication of how much longer it takes our skin to burn wearing sunscreen compared to without it. For example, if your skin burns after one minute without sunscreen and 30 minutes with sunscreen then the SPF is 30. The higher the SPF the better the protection. It pays to keep in mind that the SPF is an indication of how that sunscreen performed in the laboratory setting. In real life, often sunscreen is not applied well, like using too little, missing spots or not reapplying often enough. This reduces efficacy and SPF.

Given the high levels of UVB radiation in New Zealand, it's generally best to select a sunscreen with the highest SPF you can find, in New Zealand, that's SPF 50+. Of course, UVB is only one of the wavelengths of ultraviolet in sunlight that reaches the earth’s surface. UVA light is also harmful to our skin.

What is the difference between UVB AND UVA rays? 

Both UVA and UVB light are found in solar radiation produced by the sun. The difference is that UVA has a longer wavelength compared to UVB. This influences how deeply the rays are able to penetrate the skin, UVA rays penetrate more deeply. UVA radiation makes up 95% of solar radiation and plays a major role in photoaging and the way that sunlight influences how our skin looks over the years. Changes in photoaging include wrinkles, sagging skin, yellow discoloration, and pigmentation. UVA radiation can also cause skin cancer. In contrast, UVB rays penetrate less deeply but are responsible for sunburn and have a greater role in skin cancer making up the remaining 5% of solar radiation

Why is it important to have good UVA protection?

UVA rays have a lot of harmful effects on our skin including an increased risk of skin cancer, melanoma and premature aging. UV radiation is present at fairly consistent levels the whole year round and UVA can also penetrate clouds and glass, so protection is needed even on a cloudy day and during winter.

To protect from UVA it's recommended that you choose a sunscreen labeled as broad spectrum. This means that it protects from both UVA and UVB. For sunscreen to claim that it is broad-spectrum the UVA protection factor must be at least 1/3 of the labeled SPF. The Australian and New Zealand Sunscreen Standards require all sunscreens and skin care products to be broad spectrum. Makeup with SPF products may not have such good UVA protection.

Why is it so important to incorporate sun protection into your daily routine?

New Zealand has the highest rate of melanoma in the world. Non-melanoma skin cancer is actually much more common than melanoma although maybe less well known. When we combine non-melanoma and melanoma skin cancer the statistics suggest that up to 2/3 of New Zealanders will have some form of skin cancer in their lifetime. So you see the risk is massive for Kiwis. 95% of skin cancer is caused by sun exposure and so protecting from sun exposure across a person's lifetime helps to reduce the risk of skin cancer. Daily sunscreen use has been shown in scientific studies to reduce the risk of Melanoma and non-melanoma skin cancer, precancerous sun spots, photoaging and even delays the appearance of moles in children. The risk of skin cancer is more than 10 times the risk of a road traffic accident yet we wouldn't consider getting in the car without fastening our seatbelts every time—we should think about sun exposure in the same way.

The other advantage of applying sunscreen daily and making it part of your routine is that it requires less ‘mental administration’ in terms of thinking about what you're going to be doing that day or if it's a sunny day and only applying sunscreen then. There are many things that can come into play and can increase your UV exposure, for example, every1000m in altitude, UV levels increase by 10-12%, so if you put it on every day then you always have it on no matter what the day brings. We know that incidental sun exposure is important, for example walking from your car into a building or going out at lunchtime, overtime those exposures cumulate and leads to skin damage. Having sunscreen on every day helps to protect against that.

Sometimes people ask me about sun exposure and vitamin D. Our skin helps make vitamin D after exposure to UVB light. However, the amount of UVB needed is really much less than most people expect. For example, generally, you only need to expose about 10% of your skin body surface area for 3-7 minutes a day. We also know from studies that wearing sunscreen is not associated with vitamin D deficiency and vitamin D is produced even when we're wearing sunscreen. This is because sunscreen does not protect against all UV B radiation. Particularly in New Zealand where ultraviolet radiation levels are so high vitamin D deficiency due to sunscreen use should not be a concern for most people.

Sometimes a tan is considered healthy, or a sign our skin is protected from burning and sun damage but this is not correct. Any tan is a sign that UV rays have damaged the DNA of our skin cells and accelerated the aging process.

Can you feel UV rays on your skin?

The light from the sun includes visible light which can be seen, infrared light which feels warm and UV light. UV light cannot be seen or felt on your skin. Unfortunately, although we cannot see or feel UV light it is harmful for our skin, increasing the risk of skin cancers and photoaging which causes wrinkles. Because of this, it's important to protect our skin even when we don't feel warm, such as when we are in the water and particularly in the snow as it can reflect as much as 80% of UV radiation. In New Zealand UV radiation is at high levels almost the entire year and so it makes sense to make sun protection part of your daily routine so that you don't get caught out. For example, applying sunscreen each morning means over time you’ll get real benefits without even having to think about it.

Urban List recommends: When it comes to dermatologically tested products, we love and trust (especially for sensitive skin) La Roche-Posay’s Anthelios range with broad-spectrum, very high sunscreen protection against UVA and UVB rays. The lightweight, virtually invisible, non-greasy sunscreen formula blends seamlessly into the skin—making it our go-to product for incorporating SPF50+ into a daily skincare routine for daily protection against sun damage. The Anthelios range of facial sunscreens suits all types of sensitive skin, including oily, acne-prone skin, and dry skin types. Consider this your number one anti-aging product in your skincare repertoire.

What are your tips for helping people remain vigilant with SPF?

Wearing sunscreen daily is really my top tip because over time you'll do it automatically without having to think. I also think it's really helpful to make use of protective clothing particularly for parents who may be applying sunscreen to themselves as well as their children—this can get really time-consuming. For example, wearing a long-sleeved rash shirt reduces the amount of sunscreen that you need to apply—and reapply—actually gives you better sun protection.

Can sunscreen go underneath makeup?

Absolutely. A lot of people recall the high SPF sunscreens that they might have used during their childhood which were sticky and thick and not very nice to use. But sunscreens have come a long way since then. There are now some really nice light formulations that work well as a primer or base for makeup.

What kind of sunscreen would you recommend for everyday use? 

Sunscreen should be broad-spectrum and I'd recommend choosing one with the highest SPF possible (SPF50+). Other than that I often say the best sunscreen is the one that will be used, so it has to feel nice on your skin and have a texture that you're happy with.

What kind of sunscreen would you recommend for people with sensitive skin or allergies?

One of the ways we classify sunscreen is whether it contains are physical or chemical ultraviolet filters. The physical filters include zinc oxide and titanium dioxide and these work by reflecting UV light. In contrast, the chemical filters absorb UV light. When we look at people who develop sunscreen allergy (allergic contact dermatitis) to ultraviolet filters, these tend to be to the chemical sunscreens. So if you have sensitive skin it's good to look for a sunscreen that contains physical filters as these are less likely to cause allergy. The other thing to think about is the inactive ingredients in the sunscreen, for example, preservatives and fragrances. These can also lead to irritation and allergy so if you have sensitive skin it's good to look for a sunscreen that is fragrance-free.

What else would you recommend in addition to sunscreen to help protect against sun exposure?

It's really important to remember that sunscreen is only one part of sun protection and should be combined with other measures such as wearing a hat, sunglasses, protective clothing such as long-sleeve shirts and seeking shade. When UV levels are really high then it's best to avoid being outside during the middle of the day. Sunscreen is great for the parts of the skin that can't be covered up easily, for example, the face, but shouldn’t be relied on as your only form of protection.