Sunscreen, SPF, and Skin Cancer: Be Safe in the Summer Sun!

An oldie but a goodie: this post was originally published on 6/29/17.

It’s summertime here in Florida, and that means tons of sunshine! We certainly earn our nickname of the Sunshine State: on average, we can expect to have more than 260 days of beautiful sunshine every year. All of that sun is great for outdoor sports, beach days, and ensuring you reach your Vitamin D needs, but it can also wreak havoc on your skin’s health. So how do you protect yourself? In today’s blog post we’ll explore what the sun damage actually does to your skin, how sunscreen works, and various techniques to protect your skin from the harsh sun rays.

Why is the sun actually bad for your skin?

It’s pretty well-known that sun exposure and sunburns are bad for your skin. But how does the sun actually damage your skin? Sun exposure negatively affects your skin in two primary ways: exposure can cause premature sign of aging and skin cancer. Sun exposure accelerates skin aging because over time, the sun’s ultraviolet (UV) light damages the fibers in the skin called elastin. When these fibers break down, the skin begins to sag, stretch, and lose its ability to go back into place after stretching. The skin also bruises and tears more easily, taking longer to heal. Sun exposure can also cause pre-cancerous (actinic keratosis) and cancerous (basal cell carcinoma, squamous cell carcinoma and melanoma) skin lesions because exposure to UV rays decreases the skin’s immune function and damages the skin’s cellular DNA, producing the genetic mutations that can lead to skin cancer. Cumulative sun exposure causes mainly basal cell and squamous cell skin cancer, while episodes of severe sunburns, usually before age 18, can raise the risk of developing melanoma.

Wait! What about Vitamin D?

Although premature aging and skin cancer are scary, the sun isn’t all bad! When we experience sun exposure, our skin reacts by producing Vitamin D, which is important for our overall health in that it is linked to improved mood, sleep, and decreased risk of certain types of cancers. Completely avoiding the sun can put you at risk of becoming Vitamin D deficient. So how do you know how much sun is good for you, and how much is too much sun? According to Carey Bligard, MD, after about 15 minutes of unprotected sun exposure, your skin’s production of Vitamin D drops off and skin damage can begin. Of course, this recommendation is just an average: if you are very pale you may want to shorten your unprotected exposure to just 8 or 9 minutes, whereas if you have naturally dark skin, it may take longer to reach your max Vitamin D production.

How does sunscreen work?

Now that you know the pros and cons of sun exposure, lets talk sunscreen. There are two primary types of sunscreens: physical and chemical. Chemical sunscreens work by absorbing the sun’s rays (via chemicals like Octylcrylen, Avobenzone and Octinoxate) and physical sunscreens protect your skin from the sun by deflecting or blocking the sun’s rays (by using natural agents like zinc oxide and titanium dioxide). Chemical sunscreens can offer more coverage, but take about 20 minutes after application to be effective and can be more harsh on sensitive skin. On the other hand, physical sunscreens work immediately and are generally non-irritating, but they tend to be more chalky and thick than chemical sunscreens. Most sunscreens today offer a combination of chemical and physical ingredients to offer the coverage benefits of chemical sunscreens and sensitive skin benefits of physical sunscreens.

Both physical and chemical sunscreens can offer good sun protection

S.P.F. refers to a sunscreen’s Sun Protection Factor. According to the FDA, SPF is a measure of how much UV radiation is required to produce sunburn on sunscreened skin relative to the amount of UV radiation required to produce sunburn on unprotected skin. As the SPF value increases, sunburn protection increases. For example, an SPF 15 sunscreen blocks 93 percent of UVB radiation, while an SPF 30 sunscreen blocks nearly 97 percent.

After deciding on your preferred SPF level and whether you want physical or chemical sunscreen, you also want to ensure that your sunscreen is labelled as “broad spectrum.” This means that the sunscreen is effective at blocking both types of UV rays: UVA and UVB. UVB is the chief culprit behind sunburn, while UVA rays, which penetrate the skin more deeply, are associated with wrinkling and other signs of aging. Both are carcinogenic, so you want to be sure that your sunscreen protects you from both!

How do you get the most out of your sunscreen?

According to the Skin Cancer Foundation, to ensure that you get the full SPF of a sunscreen, you need to apply 1 oz (about a shot glass full). Studies show that most people apply only half to a quarter of that amount, which means the actual SPF they have on their body is lower than advertised. For example, if your sunscreen is SPF 30 but you only apply half of the recommended amount, your protection may be as low as 10 or 15 SPF. Sunscreens should be applied 30 minutes before sun exposure to allow the ingredients to fully bind to the skin. Reapplication of sunscreen is just as important as putting it on in the first place, so reapply the same amount every two hours. Sunscreens should also be reapplied immediately after swimming, toweling off, or sweating a great deal. You can also compliment your sunscreen use with other sun protection, like sunglasses, hats, and seeking shade during midday.

Follow these sun safety tips for a healthy summer!

With these sunscreen tips, we hope you have a safe and fun summer!




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