Ask Me Something: Benefits of wearing sunscreen in all seasons

Even though summer has given way to fall, protecting your skin from the sun doesn’t stop when the leaves start falling.

But there are myths and misconceptions surrounding the use of sunscreen. From what level of sunscreen you should wear to its importance all year-round, Dr. Ryan Lewinson, MD’18, PhD’18, a certified dermatologist and CEO and co-founder of the UCeed-supported startup, All Skin, helps sort out the facts.

Should you wear sunscreen? 

Yes, sunscreens create a coating on the skin that filters UV (ultraviolet) light, reducing the risk of damage to the skin. That’s important because UV-related skin damage is associated with development of skin cancers and photoaging. Wearing sunscreen is a safe and effective way you can protect your skin and maintain skin health.

What level of SPF (sun protection factor) should you use?

Dermatologists recommend using at least SPF 30 and reapplying at least every two hours, more often if sweating or swimming. So, if you know you are going to be outside and active, using SPF 50 is a better choice to account for that. For your daily wear, SPF 30 you can probably get by with.

How effective is spray sunscreen?

Spray sunscreen can be very effective, but here's where people usually go wrong with it — they spray it and walk away. You've got to spray it and make sure you're rubbing it in. The reason is that the spray is not going to have a consistent stream all the way across the skin, and so you're going to have gap areas that don't have as much coverage. Spray it, rub it in and you're good to go.

What ingredients should you look for in sunscreen and which should you avoid?

There’s no such thing as an ingredient that is universally “bad” for everyone, since sunscreens are regulated by Health Canada as drugs and therefore are considered safe. However, there are certain situations where choosing sunscreen with or without certain ingredients may be a good idea depending on your skin profile. For example, if you have eczema or if you have really sensitive skin, choosing a sunscreen that avoids common irritants like fragrance is a good idea. Similarly, if you have acne, choosing a sunscreen that avoids oils so that you're not blocking your pores is recommended. Or, if you have a darker skin type or have concerns of hyperpigmentation, choosing a tinted sunscreen with iron oxides can be helpful and can reduce “white cast.” 

Nowadays, you can check UV index levels on a weather app — should we be wearing sunscreen even when UV index levels are low?

A UV index of three or greater usually means that the risk of burning is substantial, and so sunscreen is definitely needed in those scenarios. If the UV index is below three, it means your risk of burn is lower, but UVA levels are much more constant through the day and seasons. UVA light is what's contributing to photoaging but also potentially certain types of skin cancers. So, for that reason, wearing sunscreen is a good idea regardless of UV index if you will be exposed to sunlight during the day.

Is wearing sunscreen in the winter just as important as in the summer?

Yes, it's still really important. In the wintertime, the snow can reflect up to 80 per cent of UV rays, so you almost double your exposure just from that. Lastly, UV index really is only capturing a tendency to burn, UVA levels tend to be fairly constant, even in winter. So even with a low UV index, there’s still UVA exposure. So, in short, be sure to wear your broad-spectrum sunscreen in the winter.