Busting the Myths of Using Sunscreen

Even on cloudy days such as this it’s a good idea to wear sunscreen.

Many people are becoming more aware of the damaging effects of sun on our skin.  It directly correlates to aging and skin conditions such as pigmentation, sunspots, and even skin cancers.  However, as a health care professional, I’ve heard so many myths and misunderstandings surrounding the topic.  Let’s talk about the myths of sunscreen and its importance in skin health.

Sunscreen use is one of the first tips that dermatologists give to patients.  It’s also the most important of any skincare routine.  However, when used incorrectly with the incorrect amount and time of use, you may not get the long-term benefits that it boasts.

If it’s not sunny outside do I need a sunscreen?

Living in the Northern Hemisphere the UV index is higher (meaning that the strength of sunburn producing UV radiation at a particular place at a particular time is higher).  This means our skin takes on a higher burden of care.  Even on cloudy days, the sun’s UVA and UVB rays penetrate the skin, causing premature aging, sunspots, liver-spots, and pigmentation.

Is chemical or physical sunscreen better?

You may hear there are two types of sunscreen that may be purchased: either a chemical or physical sunscreen.  Whereas chemical sunscreen is absorbed into the skin and then absorbs UV rays, converting them into heat and releasing them from the body, physical or mineral sunscreens sit on top of the skin and reflect UV rays away.

Physical sunscreen is better for sensitive skin as it sits on top of the layer rather than being absorbed into the dermal layers.  Chemical sunscreens are generally lighter and easier to use but may be more irritating to sensitive skin types.  While I get many questions such as which is a better sunscreen type, I always say that the best sunscreen is the one that you will use daily. 

There are so many different types of sunscreen to choose from.  Ultimately, it boils down to which one will you use every day.  Try different sunscreens and use ones that are non-irritating, non-comedolytic (pore-clogging), and texturally appealing to you.

Is higher SPF sunscreen better?

SPF stands for sun protective factor.  It’s a measure of how much UV light is required to cause a sunburn on protected skin.  For example, take a fair-skinned individual who takes about 10 minutes to burn in the sun normally without any sunscreen.  This individual wearing a SPF of 15 means that it takes them 15 x 10 = 150 minutes to burn while wearing the sunscreen.  Thus, an SPF of 15 means that the fair-skinned individual can stay in the sun for 150 minutes or 2.5 hours without burning with the sunscreen of SPF 15.  It’s a lot I know.  However, when you factor in sweating, rubbing off on clothing, SPF 15 is not actually recommended.  Dermatologists recommend SPF with at least 30 for optimal protection against the sun’s UV light.  The general rule is that an SPF 50 and beyond makes very little difference from a sunscreen of SPF 100.  And no sunscreen offers 100% protection from UVB light.

Photo of me walking on the streets in Shanghai, China in 2019.  Many people use umbrellas as sunblock on top of their sunscreen.  The secret to glowing, youthful skin is protection against UV light. 

Don’t I need sunlight exposure for vitamin D?

While Vitamin D is essential for absorption of calcium and improvement of bone health, we only need a small amount of exposure a day.  It doesn’t take much sun exposure to produce vitamin D.  No more than 10 minutes exposure to arms, legs, abdomen and back 2-3 times a week is required.  For myself, I take a multivitamin that contains vitamin D reducing the need for sun exposure.