A blog chronicling skin care, DIY beauty products, wishes and daydreams, life transitions, and other random stuff...

Wednesday, April 21, 2010

Summertime! Does SPF Matter? What's the Dif between UVA and UVB?

The sunburned days of my SoCal youth have caught up with me via a serious skin cancer scare, so I can't get a tan any more.  Unless it's a sunless tan.

Last year, a suspicious discoloration was discovered during a routine physical.  A spot on my back that I can't reach with sunscreen...that I've never seen.  I was sent to the dermatologist the next day, and the black, weirdly-shaped spot, that I never knew existed, was immediately sliced out of my back in the doctor's office.  I walked out a bit shocked.  I thought that I've been pretty good about using sunscreen as an adult. Thankfully, the tissue was benign, but I need to get the scar, and other funny colored markings on my body, checked yearly for the rest of my life.  It's not cancer right now, but it can turn in to cancer later.  This was another brutal reminder of how the past can creep up on you.


BeingTan:  it makes us look skinnier, more alive, healthy, outdoorsy, like we actually run around in the sun...yeah, those are good things!  But what is a tan, really?  A tan is your skin is freaking out, creating extra melanin to fight against the damaging (and cancer-causing) UVA and UVB rays that are assaulting it.  It's your body defending itself.  The darker skin is basically, a scar.

Most sunscreens protect against UVB rays, but the UVA rays are like super-villains:  They force themselves through windows, sunscreens, and the epidermis, straight to the deep layers (dermis) of our skin.  Layers that even the craziest skin creams can't penetrate.  Layers that only a knife, needle or laser can reach.  UVA rays jumble up and confuse skin cell DNA.  Your skin overreacts and creates mutated cells, that stimulate melanin, and your skin gets dark.  And cancer grows.  It's intense.

Now that I am older, I always wear sunscreen, even on rainy days.  I don't want the wrinkles and hyperpigmentation that result in sunbathing.  These are a few more unwelcome signs of sun damage that have haunted me in the past ten years. 

Since the minor surgery to remove my weird skin cells, I'm a fanatic about all-over sunscreen.  Especially the tips of your ears!  I'm going to do some serious research about self-tanners.  There are some speculations that the chemicals in self-tanners can be dangerous, too.  I'll post my research results soon.

I've re-posted an article below, all about the best sunscreen ingredients, UVA (evil) and UVB rays, chemical vs physical sunblocks, and a really cool diagram of how the skin soaks in rays, and how the sunscreens work: 




High-SPF Sunscreens: Are They Better?

WebMD discusses the pros and cons of high-SPF sunscreens.
By Salynn Boyles (WebMD Feature) / Reviewed by Louise Chang, MD
If you’ve shopped for sunscreen lately, you have probably noticed the proliferation of products with ever-higher sun protection factor (SPF) ratings.
Just a few years ago, it was hard to find a sunscreen claiming an SPF higher than 45. These days, the shelves are lined with products from companies such as Banana Boat, Coppertone, and Aveeno touting SPF ratings of 70+, 80, and 90+.
Neutrogena recently introduced Ultra Sheer Dry-Touch Sunblock SPF 100+.  But is a 100+ or a 90+ sunscreen really that much better than one with an SPF of 15?  SPF 100: Twice as Good As SPF 50?
SPF refers to the ability of a sunscreen to block ultraviolet B (UVB) rays, which cause sunburns, but not UVA rays, which are more closely linked to deeper skin damage. Both UVA and UVB contribute to the risk of skin cancer.
It is a measure of the time it would take an individual to burn in the sun if they were not wearing sunscreen vs. the time it would take with sunscreen on.
“SPF is not a consumer-friendly number,” says Florida dermatologist and American Academy of Dermatology (AAD) spokesman James M. Spencer, MD. “It is logical for someone to think that an SPF of 30 is twice as good as an SPF of 15, and so on, but that is not how it works.”  According to Spencer, an SPF 15 product blocks about 94% of UVB rays, an SPF 30 product blocks 97% of UVB rays, and an SPF 45 product blocks about 98% of rays.  “After that, it just gets silly,” he says.
Sunscreens with higher SPF ratings block slightly more UVB rays, but none offers 100% protection.  Spencer says SPF 15 sunscreens are fine if used correctly, but he recommends SPF 30 products to his patients because few people apply sunscreens as heavily or as often as they should.
Farah Ahmed, who is general council for the cosmetics industry group Personal Care Products Council, concedes that the difference in sunburn protection between the medium- and high-SPF sunscreens is not great.  But she says the high SPF products may better protect against long-term skin damage and exposure-related skin cancers.
In a written statement, Neutrogena notes that because most people use far less sunscreen than is recommended, high SPF sunscreens can offer better protection.  “Higher SPFs used over a lifetime may translate to healthier skin in later life,” the statement reads. “While the difference in the percentage of ultraviolet radiation blocked between an SPF 55 and SPF 100+ may be slightly less than 1%, applying an SPF 100 may lead to much less cumulative sun damage over a lifetime.”
What about UVA Rays?
Many of the high SPF sunscreens use chemical filters to block UVA rays, which may offer only marginal protection.  That’s because avobenzone or Parsol 1789 and Mexoryl, two UVA filters, break down quickly and lose effectiveness in the sun unless stabilized.  The stabilization process is difficult and few companies have been able to prove that they can do it, Spencer says.
San Francisco-area dermatologist Sonia Badreshia-Bansal, MD, recommends two chemical-based sunscreens to her patients -- Neutrogena sunscreens with Helioplex and Loreal’s LoRoche Posay with avobenzone.  She says helioplex is a stabilizer that has been proven to keep avobenzone from breaking down.  Spencer also recommends Loreal’s sunscreens that have Mexoryl as the active UVA-blocking ingredient.
Badreshia-Bansal says she prefers barrier-type sunscreens containing zinc oxide or titanium to chemical ones, but she concedes that her patients don’t usually like the over-the-counter versions because they tend to be thick, pasty, and opaque.  She frequently prescribes medical-grade sunscreens with micronized zinc formulations that are less heavy and chalky. She recommends SkinCeuticals sunblocks with SPF 30, which contain high concentrations of micronized zinc oxide and/or titanium oxide, and Obagi sunscreens with SPF 30 and micronized zinc for all skin types.  “I’m darker-skinned and I can put them on my skin without it showing,” she says. 
Both agreed that even the best sunscreens need to be used properly to work.  “The best way make sure you are protected is to reapply sunscreen often,” Spencer says. “You just can’t put it on in the morning and forget about it. I don’t care if it’s SPF 800 or the best UVA protection, after a few hours it’s gone.”

Consumer Groups Rate Sunscreens
How well do sunscreens really work? Until the FDA comes out with its rating system, Spencer and Badreshia-Bansal say it is difficult to know.   Whatever product you choose, experts recommend using a water-resistant sunscreen applied liberally, a half hour before going outdoors. Sunscreen should be reapplied at least every two hours or after swimming, drying off, or sweating.









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1 comment:

  1. nice blog
    Great Information
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