There are a lot of questions when it comes to protecting yourself from the sun – how much sunscreen should I wear? If I get a bad burn tomorrow, will my skin bubble up and fall off in 5 years? Is wearing sunscreen with SPF 100 like having my own personal skin blanket? And if you’re a beach junkie like I am, you’ll want to know what’s true and what’s not (or what you can get away with while still getting a nice golden tan). So here is the world of sunscreen according to Lauren – what you need to know about the sun, your skin, SPF, and the wonderful ozone layer that keeps the sun from frying us into oblivion.
First, a little physics:
UV rays shine down on us from the sun, alongside normal visible light. There are three types of UV rays – UVA, UVB, and UVC. UVA rays have the longest wavelength, UVC rays the shortest, and UVB are in the middle. As with all electromagnetic radiation, the shorter the wavelength, the more energy the wave carries, and the more damage it can do. UV rays are troublesome because they carry enough energy to cause irreparable damage to DNA in cells exposed to them (the skin), thereby causing cancer in some cases. UV rays are, in fact, the main factor responsible for skin cancers. Luckily for us, though, the earth’s atmosphere (especially the ozone layer) absorbs much of the UV radiation emitted by the sun – all of its UVC rays and some of its UVB. As a result, 95% of the solar radiation reaching the earth’s surface is UVA rays. Without this protective ozone bubble around us, the sun’s rays would be so strong that life would be confined to the oceans – and was, for billions of years!
UVC rays are more than capable of causing DNA damage, but since the atmosphere absorbs them, they pose no threat to us. UVB rays, however, can reach the earth’s surface and penetrate the superficial layers of the skin, causing skin reddening and pain (aka sunburn). These rays are strongest in the summer months, when the sun’s light hits us more directly. UVA rays, on the other hand, are constant year-round, can penetrate through clouds and glass, and infiltrate the deeper layers of the skin – causing wrinkles and skin aging. This makes UVA rays especially dangerous since you won’t feel their effects – they don’t contribute to sunburn – but can still cause a significant amount of damage to your skin.
Now a little physiology:
Melanin, a natural pigment found in skin, is your own personal sunscreen – it absorbs those destructive UV rays and dissipates them as harmless heat. Melanin is what gives our skin color, and we produce more of it in response to the sun. However, if we expose ourselves to too much direct sunlight before our body can produce sufficient melanin to absorb them, those UV rays can cause damage to your skin. Now, keep in mind that your body absolutely has mechanisms to repair DNA damage – we’d all be walking melanomas if it didn’t – but, there are times when the damage is beyond repair or when it escalates unchecked for a period of time – and this is when cancer develops. So your best bet is to try to prevent and reduce that damage as much as possible. Hence, the need for sunscreen!
Now, on to sunscreen itself:
Sunscreen is composed of compounds that either absorb (chemical blockers) or reflect (physical blockers) UV light. Each compound blocks a range of wavelengths within the UVA-UVB spectrum, with some blocking more than others, but no one ingredient blocks all UV light. As a result, most sunscreens contain a cocktail of chemical and physical blockers in order to cover the entire spectrum. The physical blockers are inorganic metal oxides, usually titanium dioxide or zinc oxide. These are naturally occurring compounds, which are effective immediately and provide the safest and broadest range of protection. Both titanium dioxide and zinc oxide protect against UVB rays, but zinc oxide has a slightly more broad range of UVA protection.
The chemical blockers are a wide variety of ingredients, most of which are synthetic compounds. These ingredients usually take 20 – 30 minutes to take effect, so you’ll need to apply sunscreen beforehand. Recently, there has been a lot of controversy over the safety of many of these ingredients, so if you’re concerned, stick to all-natural sunscreens with physical blockers only.
Don’t let SPF lull you into a false sense of security. Sunscreens with an SPF above 15 are not giving you much added protection – an SPF of 15 blocks 93% of UVB rays, SPF 30 blocks 97%, and SPF 60 blocks 98% of rays. Check out my handy graph below, and you can see how UV protection plateaus above SPF 15. And remember that SPF is a measure of the sunscreen’s ability to block UVB rays only – not UVA rays – so missing the bulk of radiation coming your way.
To sum up (aka Lauren’s recommendations for healthy sunbathing):
* Wear sunscreen when spending long hours in the sun. DUH!!
* Apply liberally, and everywhere – applying sunscreen while you’re naked, before you hit the beach, is the best way to ensure you don’t miss a spot.
* Reapply often. Yes, most ingredients will break down in the sun, and yes, they will wash off (even the waterproof kind). Reapply every 2 – 3 hours, and more often if you’ve been swimming or profusely sweating.
* Make sure your sunscreen has broad-spectrum UVA and UVB protection.
* Always read the label and check the expiration date – yes, they do expire!
* Use a daily face cream with UVA protection all year round.
* It’s okay to be a sunscreen snob. Invest in good quality sunscreen (brands you know and trust).
* It’s never too late to start wearing sunscreen! Skin damage builds over time, so it’s better late than never.
* Remember: nothing is perfect. You will never block 100% of all UV rays. You will get burned occasionally. You will get at least a few wrinkles in your old age no matter how much sunscreen you use. Get over it.
Happy tanning everyone!!
Links and more info:
21 affordable natural sunscreens:
Lavera organic sunscreens:
Info from the EPA (and detailed info about sunscreen ingredients):