6 Misconceptions about Sunscreen: why you should apply it everyday…even in the winter!
As we move away from the warm summer months, you may be putting your trusted sunscreen aside, but hold on just a minute! There are many reasons to continue wearing facial sunscreen, even in the wet winter that Vancouver is so well-known for. In conversations with patients about their sunscreen usage I tend to see a lot of the same comments over and over:
“I don’t need it, I work inside and never burn”
“I wear it when I’m outside, but only on sunny days”
“I think it’s part of my foundation”
“I try to remember but it’s too thick so I only use a tiny bit”
“I don’t want to become vitamin D deficient so I don’t use sunscreen”
The answer I’m always hoping to hear is: “I wear it everyday, it’s a non-negotiable part of my skincare routine!”
These answers demonstrate a few key misconceptions about sunscreen, which I will attempt to correct shortly, but first, why bother with sunscreen at all?
Skin cancer rates have been steadily increasing over the past several decades. Basal cell and squamous cell cancers are both strongly linked with lifetime UV exposure. However, the relationship between melanoma and UV exposure is less linear. Though UVA and UVB exposure are correlated with melanoma, as is the number of childhood sunburns, additional genetic factors play a role as well. Behaviour that can modulate our risk factors for skin cancer include avoiding indoor tanning, avoiding sunburns, and limiting UV exposure. Wearing sunscreen daily is a significant part of limiting UV exposure and will be the focus on this post, but it’s essential to also mention the importance of other sun avoidance behaviours like protective clothing, hats, and reducing time in the sun.
When it comes to sun exposure we’re concerned primarily with UVA and UVB rays. UVA rays penetrate deeper into the skin, producing free-radicals and increasing your risk of skin cancer, as well as leading to the aesthetic changes of sun damage (wrinkles, pigment changes, loss of elasticity). UVB rays penetrate more superficially and cause tanning, burning, and also contribute to skin cancer.
Misconception #1: I work at a computer and don’t spend much time outside so I don’t need sunscreen
Though not as problematic as sun exposure, the blue light emitted from computers can also cause free-radical damage which leads to photo-aging. It’s important to note, however, that blue light is not associated with an increase in skin cancer risk. Wearing sunscreen, even when just sitting in front of a computer, can reduce the damage caused by blue-light exposure. Additionally, though not in direct sunlight, UVA rays penetrate glass, so unless you work in a windowless room, it’s likely you have some UVA exposure inside.
As a somewhat related aside, if you work at a computer, try to get outside every day and enjoy some fresh air!
Misconception #2: UV rays aren’t as strong on cloudy days so sunscreen isn’t needed
Clouds block approximately 20% of UV light from the sun, which leaves a significant amount of UV rays that are still present on cloudy days.
Misconception #3: UV rays are stronger in the summer and can’t do any damage in the winter months
If you’ve ever gotten a tan or burn in the shape of your ski goggles you will know this to be untrue! UV rays are able to cause damage throughout the year and can be intensified when reflecting off surfaces like water and snow.
There is some seasonality to UVB rays, but not UVA. UVA rays are consistently strong throughout the year, whereas UVB rays are strongest mid-day between spring and fall.
Misconception #4: SPF means the amount of time I can spend in the sun without worrying about burning
SPF stands for Sun Protection Factor and indicates the amount of protection against UVB radiation only. It is a ratio of the amount of energy required to produce redness on protected skin versus unprotected skin. Though high SPF ratings will allow more sun exposure before a burn (caused by UVB), a high SPF rating can also allow for more UVA exposure due to the increased sun exposure. UVA rays aren’t as involved in burning, but they still cause harmful free-radical formation in the skin and contribute to skin cancer.
The number is calculated based on the assumption of 2mg/cm2 of body surface. This means if you are applying a very thin layer of sunscreen, the SPF may actually be less than the bottle indicates.
Misconception #5: All sunscreens are pretty much the same
Physical sunscreens containing zinc oxide and/or titanium dioxide work as a barrier by sitting on the skin and reflecting UV light. Chemical sunscreens (azobenzene, oxybenzone, octinoxate, among others) filter and deactivate UV rays once in the skin. Many of these chemical filters were accepted by the FDA based on historical use, rather than safety data. Recent reports from the FDA have indicated that 12 of the allowed 16 chemical filters approved by the FDA cannot be assigned the GRASE badge, “generally recognized as safe and effective”. Chemical filters have been associated with allergic, endocrine, hormonal, and reproductive adverse effects. These chemicals are absorbed systemically and have been measured in blood, urine, and breast milk. Additionally, as we move into higher SPF ratings, these chemicals are found in greater amounts.
Misconception #6: Sunscreen limits my ability to convert Vitamin D
In a recent systematic review in the British Journal of Dermatology, researchers concluded that in healthy populations with regular sunscreen use, there is little reason for concern regarding Vitamin D concentration.
Tips when selecting a sunscreen
Choose physical barrier broad-spectrum sunscreens and re-apply throughout the day
Have a few different options to meet your activity needs, an SPF moisturizer for daily use on your uncovered areas like face and hands, as well as a body SPF for days that will be spent in the sun
Stick with an SPF 50 or less and focus on reapplying rather than relying on the high SPF rating
Avoid sunscreen sprays, they may not coat the skin adequately and pose an inhalation risk
Learn more and check out sunscreen options at https://www.ewg.org/sunscreen/
The best way to ensure sun protection is part of a well-designed skin care plan is to talk to your healthcare provider. Still have questions about sunscreen or skincare in general? Book a discovery call with me to learn more.
*The content of this article is not a substitute for personal and professional medical advice, diagnosis or treatment. Consult with your healthcare provider before starting any new healthcare plan.
References
PMID: 30945275
PMID: 31069788
PMID: 31418890
PMID: 22612478
EWG Sunscreen Guide. https://www.ewg.org/sunscreen/
