The Truth About Sunscreen and SPF

The CDC lists increasing exposure to UV light as “the most preventable cause” of skin cancer, the most common cancer in the United States. This includes natural sunlight or artificial sunlight from tanning beds. Since we can’t wear full-body protective suits every day to prevent unwanted sun exposure, we use sunscreen to protect our skin from harmful rays of sun. I have studied a series of videos produced by Huffington Post where Dr. Neal Schultz discusses various elements of sun protection. He debunks several sunscreen misconceptions of which you should be informed! Luckily for you, I have compiled the most important information here. Read on!

“SPF,” the acronym you see on all sunscreen products, means Sunburn Protection Factor. It’s a relative measurement that describes how much sun is required to cause a burn considering the current amount of sun protection on your skin, compared to the amount of sun required to cause a burn on skin without any protection at all (FDA).

The important thing to realize about SPF is that it’s directly related to the amount of sun you are exposed to, not the time you are in the sun (FDA). Time and amount are not always interchangeable; the sun is more powerful at noon than it is at 10AM. For example, you can ingest the same amount of alcohol by taking a shot of liquor that you can by drinking one whole beer. SPF is relative in the same way. The FDA lists other factors affecting the relationship between SPF and the power of the sun including skin type, the amount of sunscreen applied, frequency of reapplication, and the fact that “greater solar intensity occurs at lower altitudes.” All of these things must be taken in to consideration when using sunscreen.

Another important question we ask when picking out a sunscreen to use is this: what SPF should I use? It’s vital to understand how protective each SPF number is, and first you must understand that SPF values are not linear. Get this: a sunscreen labeled 15 SPF gives you 88% protection from the sun. Moving up to 30 SPF, you increase your sun protection to 95%. However, when you move up to 60 SPF, you are only getting four more percent protection from the sun.

“Part of this numbers game is drive by consumer demand,” Dr. Schultz points out.

Our advice: save some money and use 15 or 30 SPF sunscreen, and reapply often to account for sweating and rubbing off in the water when swimming. You are wasting your money on sunscreens labeled 60, 70, and 100 SPF. Plus, when using such high value SPF sunscreen, people may incorrectly assume that applying enough sunscreen and reapplying later are less important. If you don’t use enough sunscreen, the SPF value greatly decreases, and you leave yourself very vulnerable to harmful rays of sun.

Another issue I looked into was that of spray vs. lotion. I am personally guilty of taking the easy way out, choosing a spray sunscreen over lotion to cut down on time spent applying sunscreen and to prevent my hands from getting sticky/sandy/etc. FutureDerm.com tested it and concluded that spray sunscreen is less effective than lotion. This result is derived from the fact that SPF is only as powerful as the amount of sunscreen that you use on your skin. What I mean by that is this: FutureDerm discovered that when people apply spray sunscreen, they end up using much less than if they applied using a lotion. Like I discussed earlier, not using enough sunscreen drastically decreases the value of SPF protection. So, if you’re going to try and save some time by using spray sunscreen, make sure to spray a generous amount on your skin, or you’ll be making up the time saved by rubbing aloe on your burnt skin 8 hours later.

Lastly, keep in mind that UV-A rays, the dangerous rays of sun that cause skin cancer and premature aging, don’t diminish in the winter. It’s always important to wear sunscreen on a daily basis. Also, sunscreen SPF is not additive. If you wear moisturizer that provides 15 SPF protection and foundation makeup that also has 15 SPF protection, you don’t get a combined protection of 30 SPF. You get the SPF protection of the first thing that you put on your skin. If you can, make sure that the first layer is sunscreen, not foundation.

My hope from doing this research and from writing this blog post is that you’ll change your habits based on learning the facts. Take care of your skin!

Check out Dr. Schultz’s videos for yourself here:

http://videos.huffingtonpost.com/tech/how-to-choose-the-right-sunscreen-266799626