sunscreens part I

First, the big picture: the most important measure you can take to keep a “youthful” appearance—as much as your particular genes will allow—is to minimize exposure to UVA and UVB irradiation from the sun. Of course staying out of the sun as much as possible is the most sure way, but also it’s inconvenient, impractical, and not healthy from many aspects, including the psychological ones, so most people use sunscreens. The problem is finding a good one.

Sunscreen use is critical both to minimize wrinkles and cut the risk of skin cancer, which ranks as the most common cancer of all. But the subject has become complex in the past few years, so today let’s go over some of the current science of sunscreens, and the next post I’ll give some specific ideas on what you can use.sunlight

A few years ago it was easy to know what to do. Most people, even dermatologists, felt that if you used a SPF 15 or, then…wow…a 30, you would be highly protected and would not have to worry much, because a 30 was thought to allow you to be in the sun 30 times as long as if you didn’t use any sunscreen. But in the last few years as more products have been released, with higher and higher SPFs, the sunscreen field has become much more murky and confusing.

Some doctors have even gone so far as to state that using sunscreens will increase the risk for the deadliest form of skin cancer, melanoma, because many products will stop the burn (mostly from UVB), but will not stop UVA. This UVA irradiation doesn’t cause as much redness, but penetrates more deeply into the skin causing worse aging damage and a higher melanoma risk. So since you don’t get red, you think you are fine, while the sneaky UVA rays are causing their deep damage.

One simple way to remember the basic difference between A and B is: UVA,  a longer wavelength, is the aging radiation, and UVB causes more burning…however, both, in excess, lead to wrinkles, skin cancer, and even a diminished immune system. And if you sit by a sunny window, know that UVA radiation penetrates glass.

Here is a summary of some recent issues. But don’t get discouraged as you read this, because there are some solutions, which we’ll discuss in the next post…

1. The “SPF” rating only concerns the level of UVB protection. There are no good FDA standards or labeling or SPF ratings for UVA, and many products don’t offer, or even claim, good protection from UVA.

2. Many of the chemicals that do provide UVA protection, perhaps ironically, break down quickly in the sun, which is one reason sunscreens should be re-applied every 2 to 3 hours.

3. Toxicity: some of the chemicals used in sunscreens are absorbed into our bloodstream and may be toxic. Particular concern has been raised about two popular components, oxybenzone and avobenzone, which theoretically could alter our internal hormonal balance, and some doctors advise: don’t use these on pregnant women or children. Then there are the super-small, nano-particles used in some expensive new products. Again, while some have claimed these tiny particles might be absorbed, the super-cautious Environmental Working Group has concluded they are not. But the EWG recommends staying away from spray or powder products that might cause lung damage from the inhaled nano-particles. Finally, some sunscreen chemicals have been shown to produce free radicals when mixed with sunlight, and free radicals (which we try to neutralize with antioxidants) lead to skin aging.

4. While many of those issues are controversial, most doctors agree: very few people use enough sunscreen to provide adequate protection. A large Australian study showed that even “diligent” sunscreen users were only applying about half of what they should to get the advertised SPF protection, and most people only get about a quarter of the protection they think they are.

5. “Waterproof” sunscreens only last for about 40 minutes in the water, and for typical beach use, even these should be re-applied regularly.

6. If you read this blog often, you know I am a big fan of vitamin D, which we naturally get from sun exposure on our skin, and many people are vitamin D deficient. For some, this D vitamin shortage is rooted in excessive paranoia about sun exposure and many of these people use too much sunscreen. Like most things in life, moderation is the best route.

Next: SPFs and good sunscreens.

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