Last Updated on February 11, 2022 by Zwivel
According to the American Academy of Dermatology (AAD), 1 in 5 Americans will develop skin cancer at some point in their lifetime, with melanoma (or as I call it, “the M word”) being the most common form of cancer found in young adults. With statistics like these, choosing a sunscreen for health reasons over the obvious aesthetic benefits becomes all the more important.
History of Sunscreen
Ancient Greeks and Egyptians, to no one’s surprise, protected their skin from the sun with olive oils, rice extracts, and even jasmine. Zinc oxide paste (think of lifeguards with white streaks on their noses) has also been around for thousands of years.
One of the first physical barrier sunscreens was made from “red vet pet” (red veterinary petrolatum), a compound developed in the early 1940’s so soldiers fighting in World War II could better protect their skin while on the battlefield. This ingredient was also included, along with cocoa butter and coconut oil, in the iconic Coppertone suntan cream.
Roughly 30 years and several improvements later, in the mid-’70s Swiss chemist Franz Greiter introduced a calculation he called the “sun protection factor” (SPF), which is still widely used today. One of the first sunscreens Greiter created actually had a whopping SPF of 2.
A few years after SPF came in to the picture, the first waterproof sunscreens emerged and became the standard until the longer-lasting and broader-spectrum creams we mostly use today came about.
UVA vs UVB
According to The Skin Cancer Foundation, UVA rays account for up to 95 percent of the UV radiation reaching the Earth’s surface. Although they are less intense than UVB, UVA rays are 30 to 50 times more prevalent, and can penetrate clouds and glass. UVA, which penetrates the skin more deeply than UVB, has long been known to play a major part in skin aging and wrinkling.
UVB, the chief cause of skin reddening and sunburn, tends to damage the skin’s more superficial epidermal layers. It plays a key role in the development of skin cancer and varies in intensity by season, location, and time of day.
|Wave type||Skin penetration||Leads to signs of premature aging||Can cause skin cancer||Penetrates through glass|
|UVB||Short||Superficial||Yes||Absolutely yes||Not significantly|
How Much SPF Do I Need?
This isn’t a simple question to answer. The blanket statement I offer my patients is that a 30 SPF sunscreen is adequate so long as it’s reapplied every 2 hours in direct sunlight. That said, however, some practitioners believe that lighter skin tones need SPF reapplied more frequently than darker ones.
One thing we do know without question though is that an SPF of 15 blocks 94% of UVB rays, SPF 30 blocks 97%, and SPF 45 blocks a full 98% of them. Any sunscreen with SPF power greater than 45 is pretty much unnecessary as no sunscreen can offer 100% protection.
In fact, in 2007 and again in 2011 the US Food and Drug Administration were moved to propose limiting SPF labeling to a maximum of 50 in order to prevent the unrealistic claims brands regularly make for their sunscreen products. As of May 2016, this proposal had not yet been adopted by the FDA.
|- Aminobenzoic acid (PABA)|
- Padimate O
- Trolamine Salicylate
- Titanium Dioxide
- Zinc Oxide
Physical “sunblocks” contain the active ingredients of titanium dioxide and zinc oxide. These metal oxides are harder to wash off and do not degrade with exposure to light like chemicals do, working by scattering, reflecting and/or absorbing UV light (whereas chemical/organic compounds only absorb light). Physical blocks tend to have fewer adverse effects, like skin and eye irritation.
There is some evidence suggesting that these ingredients can lead to particles reaching skin cells and causing damage. However, these claims remain unsubstantiated. You can also take comfort in the knowledge that all sunscreens sold in the United States are subject to rigorous government mandated testing in order to keep out harmful substances and maintain their level of quality and skin protection.
There is only one SPF product I’m aware of that not only protects against UVA and UVB, but IRA (infrared-A light) as well, an element comprising roughly 35% of the solar energy we receive. That product is SkinMedica’s Total Defense and Repair sunscreen.
IRA rays can also penetrate deeper into skin layers than UVA and UVB rays, which makes it all the more important to be protected from them. Little is known about the impact of IRA rays at this time, but rest assured that pharmaceutical and personal health care companies are diligently working to explore their impact and develop the best ways to protect against them.
How Sunscreen Prevents Signs of Aging
While most of us are well aware of how sunscreen aids with the prevention of melanoma and squamous cell carcinoma, the many aesthetic benefits of sunscreen are considerably less well known. One 2013 study found that daily sunscreen application not only slowed, but in some cases prevented, key signs of aging like sagging skin, wrinkles and age spots.
This study was conducted on people with the highest exposure to sun in the world: white Australians. At one point a hole in the ozone layer enabled UVD – the most dangerous type of UV radiation – to reach their continent. The study concluded that after roughly 4 years of daily application, the skin of people in the control group was visibly smoother and more resilient than participants who didn’t use sunscreen at all or with any regularity.
In addition to the textural improvements that come with using sunscreen use over long periods of time, the researchers also determined there was a substantial reduction in post-inflammatory hyperpigmentation, solar lentigos (sun spots), and dermatosis papulosa nigra lesions (moles of age/genetics exacerbated by uninhibited sun exposure).
Types of Sunscreens
Depending on your skin’s sensitivity, where on your body you apply it, and your personal preferences, there should really be no excuse for not protecting your skin on a daily basis.
The AAD recommends consumers only purchase sunscreen with the following information printed on their labels:
1) Broad Spectrum – meaning it protects against ultraviolet A and B rays (UVA and UVB, respectively)
2) SPF 30 or higher
3) Water resistant or “very” water resistant for up to 40 or 80 minutes. If they’re not water/sweat proof, then they must be reapplied.
With these recommendations in mind, you can probably look through most of your moisturizers or foundations with sunscreen and toss them in the garbage (not to mention that they’ve probably already expired anyway – yes, sunscreen really does expire).
In the field of medicine, a “vehicle” is defined as a substance that facilitates a drug or material to be used by the patient. To this end there are a multitude of vehicles patients can employ to provide themselves with comfortable protection from the sun, among them liquids, creams, gels, balms/sticks, powders, sprays, and clothing.
Personally, I always thought sprays seemed like such a great idea, but unfortunately they don’t provide adequate full body protection. To rectify the situation, some companies got smart by incorporating dyes that rub away once applied to the skin – something which helps ensure that the most precious of sunbathers, our children, are properly and completely protected.
Most powder-based sunscreens are made with titanium dioxide and zinc oxide, while usually containing smaller amounts of things like antioxidants and/or essential minerals as well. These sunscreens should be the last step of your skin care/makeup routine, only applied once all of your other skin care products have been absorbed. They should be generously applied to your face, neck, and chest to function as an additional physical barrier to the sun.
Some of these products include Colorescience Sunforgettable SPF 50, BareMinerals SPF 30 Natural Sunscreen, and Peter Thomas Roth Instant Mineral Powder SPF 45. These are all tinted options that not only give you the added SPF power you need, but help diminish the skin’s oily appearance, so by extension are great for midday or repetitive applications.
The downside to these types of applications are ensuring that they’re giving you full, accurate coverage, which is why they should be applied after a cream/lotion-based SPF. Plus, they may not come in tints to fit all skin tones.
Sun protective clothing
Clothing designed to protect us from the sun does exist, and this is why I love it. UPF, which stands for Ultraviolet Protection Factor, is the way in which we quantify UV protection from clothing. A great wide-brimmed hat is not only an impressive fashion choice but an excellent UPF for the face and scalp as well.
The Skin Cancer Foundation recommends wearing a 3-inch brimmed hat or larger for adequate UPF. Inventors have recently made even greater strides in UPF than simply recommending long-sleeved shirts – they’ve actually embedded sun protection within the fibers of certain products by creating extremely small gaps between fibers to let UV protection sneak through them. Among the brands producing clothing with this special mark of protection are Sun Precautions, Coolibar, and UV Skinz.
How to Properly Apply Sunscreen
Many labels offer different application recommendations, and it should come as no surprise that I strongly suggest you follow them in order to properly protect your skin. In general, however, when it comes to applying sunscreen there are a few widely accepted recommendations that have emerged from the various clinical studies done on the subject.
First, a full shot glass of sunscreen should be applied to your body 15 minutes prior to being exposed to the sun, if the SPF is 30. Second, if you’re swimming or sweating, you should consistently re-apply your sunscreen in order to maintain full protection.
A recent study conducted at the University of California concluded that within 2 hours of its initial application, you need to reapply your sunscreen, no matter what activity you’re engaged in, to prevent cell damage caused by excess free radicals sitting on your skin. These free radicals – which are harmful for our skin or our bodies – are a by-product of the chemicals in sunscreen dissipating from continued exposure to the sun. That’s not to suggest it’s okay not to wear sunscreen, however, as wearing it still far outweighs any of the risks of not wearing it.
And don’t just use in on your face — apply it on your hands, arms, neck, or any other part of the body that is exposed to the sun.
Sunscreen Price Ranges
Whether you get the Target brand sunscreen ($1.99 for Target Sport Sunscreen 30 SPF) or stop by the Chanel counter for a $55 container of Chanel UV Essentiel 30 SPF, as you might imagine the price of sunscreen varies widely. The biggest cost differentials are by brand and the additives included – like antioxidants of vitamin E, niacinamide, and/or melanin.
Clearly, sunscreens with more additives have the benefit of offering more than just sun protection. But if your budget is screaming at the top of its lungs to keep the price reasonable, then merely getting a SPF 30 that you reapply 2 hours later should be adequate, barring any unforeseen skin sensitivity issues.
Special Populations and Sun Protection
If you’re finding exposure to the sun somewhat daunting by this point, allow me to give you a little something more to worry about. Many medications for common conditions and diseases can make you even more sensitive to the sun. These include antibiotics like tetracyclines and sulfonylureas, contraceptives, anti-hypertensives like thiazide diuretics, and anti-depressants. As a general rule of thumb, remember to check the product insert (the tiny folded piece of paper that opens like a map for all drugs prescribed in the US) for any special sun precautions.
Most people have no idea there are certain conditions that make patients more sensitive to sunlight and/or more vulnerable to sun damage and related illnesses like melasma, Polymorphic Light Eruption (PMLE), and lupus. Individuals with these types of conditions need to talk to their dermatologist – or whichever doctor they have treating their specific condition – about how they can best protect themselves.
Another population that needs to consider their sunscreen regimens are athletes. Now don’t get me wrong, I’m elated that you’re healthy and getting those endorphins flowing, but most athletes spend many hours out in the midday sun. Whether on the slopes, the track, in the water or on the turf, outdoor athletes are exposed to significantly more UV radiation than the general public. One reason in particular for this high exposure is sweating. All that sweat your producing means your sunscreen is literally sweating off, thereby increasing your photosensitivity, so make sure to reapply it based on the SPF directions.
The sun’s reflection is another cause of high UV exposure in that many of the surfaces athletes play/practice on are either light-colored, covered in white snow, or have sunrays bouncing off the water. Finally, all you marathon and half-marathon junkies need to remember that when training intensely, your weakened immune system may be associated with a higher risk of developing certain types of skin cancer.
I hope this information has provided you with enough valuable knowledge about the sun, its ability to impact our skin in a medical and aesthetic way, and how to protect yourself from it. Don’t feel you need to live your life like a vampire now that you’ve learned the risks of excessive exposure to the sun, but rather, feel empowered and allow yourself to enjoy that big burning star in the sky knowing you have all the appropriate protection!
Does sunscreen prevent tanning?
Sunscreens block some of the UV rays that cause tanning, but it depends on the type and strength of the sunscreen. Broad spectrum sunscreens that contain zinc oxide are one type of sunscreen that may effectively prevent tanning, depending on the sun protection factor (SPF). Speak with your dermatologist to learn more.
Can sunscreen really expire?
In a word, yes. So check the expiration date on your sunscreen. Certain sunscreens break down quickly, particularly those that provide UVA protection, so don’t let your sunscreen sit around too long. Also, it’s worth pointing out that if you don’t use an entire bottle of sunscreen over the course of a year, you’re probably not using enough.
Does sunscreen cause acne?
Yes, certain types of sunscreens can lead to breakouts. Look for sunscreens labeled “non-comedogenic.” This means that the product is specifically designed to avoid clogging pores or causing irritation, pimples, and blemishes.
Does sunscreen really prevent wrinkles?
Yes, researchers have shown that sunscreen, when used often enough, can prevent wrinkles and signs of skin aging. In one study, participants who applied sunscreen daily showed no detectable increase in skin aging more than four years later.
Can babies use sunscreen?
Yes and no. If your baby is under the age of 6 months, avoid applying sunscreen; instead, use other forms of protection such as hats, clothing, etc. But after that, you should apply sunscreen liberally. Make sure to choose a broad-spectrum sunscreen with an SPF of at least 15 for your baby.
Does sunscreen prevent freckles?
Yes, sunscreen can prevent new freckles from surfacing and existing freckles from becoming darker. Freckles appear as a result of exposure to UV rays. If you use a sunscreen that effectively blocks UVA and UVB rays, you should be able to prevent freckles from developing. Freckle removal procedures such as laser treatments and chemical peels can also help in some cases.
Updated, June 2017 – Zwivel Team