Naturally tanned body looks great, no question about it. You are lucky then if your body is olive color, but what about those people who cannot stay under the sun for more than 10min without getting a sunburn? One of the most popular modern myths is that you can use a commercial sunscreen to ‘screen out’ the harmful UV (UltraViolet) radiation, while still getting a tan. The sad truth is that some of those “protective” sunscreens can be toxic. Also don’t forget that tan is the physical response to DNA damage from UV radiation, and all sunscreens do is prolong the process.
There are 2 types of UV radiation, UVA, which is at a wavelength of 320-400 nm (nano meters), and UVB, at 280 to 320 nm.
UVA radiation damages the DNA indirectly by creating oxidants, which damage the DNA structure. This can cause both rapid skin aging, and cancer. UVA is not blocked by sunscreens. However, clothing does provide some protection. Also, it is a myth that clouds block UV radiation. You can be damaged just as much on a cloudy day as on a sunny one. When UVA radiation begins to create oxidation, this oxidizes the melanin, causing it to darken, and be redistributed. However, this does not lead to the production of more melanin, so it’s protective value is limited. Tans from UVA radiation are short-lived, only cosmetic, and rapidly fade once exposure to UVA is reduced.
UVB is more dangerous. Luckily, a lot of the sun’s UVB radiation is blocked by the Ozone Layer of the upper atmosphere. Sunscreens are designed to protect against UVB radiation. UVB causes direct damage to both the skin, in the form of sunburn, and the skins DNA. When the DNA begins to be damaged, the skin responds by producing more melanin. This delays the tanning process, and will not become visible until about 72 hours after exposure. But it does protect against further photo-damage to the skin, and lasts much longer than that caused by UVA exposure.
As you can see, in order to get a good, deep tan, you must damage some DNA. In unprotected skin, especially in light-skinned people, this happens quite rapidly, often in 10 minutes or less. However, the tan is not complete protection, and the longer you stay exposed to UV radiation, the more damage you are doing. UVB will quickly begin damaging actual tissue, resulting in painful sunburns. Sunscreens are designed to offer some protection from this, and to allow you to spend more time in the sun, resulting in more DNA damage, but a deeper tan. Sunscreens are rated by an SPF rating (Sun Protection Factor). The SPF is the ratio between the amount of UVB that causes skin redness in unprotected skin, vs the amount of UVB that causes redness in sunscreen-protected skin. So, a sunscreen with a rating of 15 SPF means you can risk 15 times the minutes of exposure to UVB before beginning to experience tissue damage. In other words, if you would normally begin to burn in 10 minutes, a 15 SPF sunscreen will protect you up to 150 minutes. However, an SPF of 30 does not necessarily double the amount of time you can safely spend in the sun. An SPF of 15 blocks around 93% of UVB. SPF 30 blocks around 97%, and so on. So there is a limit to what sunscreens can do, and none of them block UVA. The entire legitimacy of the SPF rating system has come under fire in recent years, with many scientists and health care workers labeling it as pure “junk science” with no real meaning.
Most commercial sunscreens work by the reactions of chemicals, such as PABA, oxybenzone, and more. While protecting against sunburn, these chemicals are suspected of causing endocrine imbalances and can increase the risk of skin cancer significantly. These sunscreens often contain other chemicals that penetrate deep into the skin and can cause estrogenic activity, which can throw the body’s hormone balance off significantly on cell proliferation and gene induction in mammalian and amphibian cells.
A better choice would be to opt for using natural sunscreens, such as plain shea butter and cocoa butter. There are plenty of organic brands as well, check out the best 7 ones (according to EWG report):
- Green Screen D Organic Sunscreen, SPF 35, by Kabana Skin Care
- Aubrey Organics Natural Sun Screen, Green Tea, SPF 30+
- Aubrey Organics Natural Sun Sunscreen, Sensitive Skin/Children, Unscented, SPF 30+
- Aubrey Organics Natural Sun Saving Face Sunscreen, SPF 15
- Green Screen Organic Sunscreen, Bronze, Neutral, Nude or Peach, SPF 32
- Green Screen Organic Sunscreen, Original, SPF 31
- Aubrey Organics Natural Sun Sunscreen for Active Lifestyles, Tropical, SPF 30
One thing that is not in question: UV radiation can be harmful, so proper protection is necessary. Your best bet is to study all the information available, and make an informed choice. Then, go out and enjoy a day in the sun…
‘Endocrine activity and developmental toxicity of cosmetic UV filters—an update’, by M Schlumpf, et. al, Toxicology 1 205 113–122 (Dec 2004 )
Klann A, Levy G, Lutz I, et al. (2005). Estrogen-like effects of ultraviolet screen 3-(4methylbenzylidene)-camphor (Eusolex 6300)
Environ Res, 97:274-281