|
What is the difference between UVA and UVB rays??
 When ultraviolet light hits the skin, it stimulates an increase in the production of melanin, resulting in a suntan. There are two kinds of ultraviolet rays, Ultraviolet A (UVA) and Ultraviolet B (UVB). Both are harmful to your skin in different ways.
UVB rays are "short wave" solar rays that penetrate only the outer layer of your skin. They are far more likely to cause immediate damage through sunburn and are strongest between 10 a.m. and 4 p.m. It is the UVB rays that cause the redness that you see during sun exposure. This redness warns you that you have had too much sun so that you will get out of the sun. UVB doesn't penetrate glass, and exposure is pretty low on cloudy days.
We now know that UVA rays, which are "long wave" rays, are far more harmful in causing long-term damage. The UVA rays are strong all day, even before 10am and after 4pm, unlike UVB. They do not cause redness as UVB does, so you do not have a warning system that you are getting too much UVA. UVA rays penetrate deep into the dermis and cause damage that can take years before the ill effects show up, often in the form of wrinkles, brown spots or even skin cancer. Since UVA rays cut through clouds and easily penetrate windows (unless they have protective coating), you should wear sunscreen on exposed areas at all times - even in winter, or while inside a building, a car or a plane. Incidentally, tanning beds use UVA - people think they're safe because you don't burn, but they can still age the skin and cause cancer. In fact, UVA rays are more harmful than UVB rays because they penetrate deeper and you do not have redness as an early warning sign that you are getting too much.
Back to Top ^
Do sunscreens protect against both UVA and UVB rays?
 Early sunscreens were designed to protect only against UVB rays - the ones that cause most sunburns. In fact, the SPF system that we use to classify sunscreens is a measure of how long a sunscreen will delay burning. So a sunscreen with an SPF of 15, when properly applied, allows you to stay in the sun 15 times longer than you would normally be able to without getting a burn. Because UVB is the one that causes redness, the SPF number ONLY applies to UVB protection.
Unfortunately, this system does not tell you anything about UVA protection. The FDA is considering a new labeling system for sunscreen that includes a UVA system, but for now, there is no standardized way to measure UVA exposure. Many companies have their own way to measure UVA protection but few agree on which system is correct. This is unfortunate because UVA is the primary cause of premature aging and skin cancer. The good news is there are sunscreens that protect against both types of ultraviolet ray, and recently consumers in the US have been given more and better options. The key is to be able to read the labels so you know what ingredients to look for.
Back to Top ^
How can you tell if a sunscreen protects against both UVA and UVB rays?
 Sunscreens that protect against both UVA and UVB rays usually say "broad spectrum" somewhere on the label. But not all broad-spectrum sunscreens are created equal. For a long time, the only option available in the US was Parsol 1789. Ironically, Parsol breaks down when exposed to sunlight and can lose a lot of its protective abilities within just 30 minutes.
Recently, companies have figured out how to stabilize Parsol so it doesn't break down as quickly and lasts a lot longer. A product with stabilized Parsol that I recommend is Neutrogena's Helioplex; Active Photobarrier Complex by Aveeno is also good. It must be said, though, that even though these products last longer they can still rub off or be diluted by sweat. They should still be reapplied every hour-and-a-half or so.
Two years ago, in summer of 2006, the FDA approved Mexoryl SX, a UVA blocker that's been available in Europe and Canada for years. Mexoryl also provides UVA protection, however it is important to know that the Mexoryl SX approved in the US does not protect quite as well as Mexoryl XL, which is only available in Europe and blocks more UV rays than the Mexoryl SX. In other words, it is still better to buy your sunscreen in Europe- look for Mexoryl XL on the label. In the US brands that contain Mexoryl SX are Anthelios by La Roche Posay, Vichy Complete Protection, L’Oreal and Lancombe.
Back to Top ^
Are there any sunscreens that are better or worse for certain skin types?
 Of course, everyone should use sunscreen, regardless of their skin type, but some products are better for some than they are for others. In my book, The Skin Type Solution, I outline the 16 different skin types and how to best care for each, but the most basic factors when it comes to sunscreen is how sensitive your skin is, do you have unwanted brown spots, and is your skin dry or oily.
Click here to shop for sunscreen products
A lot of people with oily, sensitive skin don't like to wear sunscreen because it makes them break out. But it's still important for them to use sunscreen - one study showed UV exposure can clog pores and aggravate existing zits, and pigmented acne scars will get darker in the sun. Sunscreens often clog pores and lead to acne.
Oily Skin Types
The vehicle through which the UV-blocking ingredients are delivered is important. I prefer gels and SPF-containing powders over creamy lotions for people with oily skin. Cover this with a powder SPF. Never rely on the powder for SPF protection because they are not strong enough. However, layering a SPF powder over a sunscreen gel will give you sun protection without adding extra oiliness. Powders - such as those by Neutrogena Healthy Defense, Philosophy or Colorscience - are best because they help absorb oil. Suncreens for slightly oily skin include: Anthelios Fluide Extreme SPF 15 by La Roche-Posay or Aveeno Continuous Protection Sunblock Lotion. If you have very oily skin, you will prefer Pedinol Ti_Screen Sports Gel SPF 30 and Neutrogena Ultra Sheer Dry Touch SPF 55. A sunscreen mist suited for oily skin is June Jacobs Oil-Free Sunscreen Mist SPF 15. My favorite lotion sunscreen for slightly oily/ combination skin is Citrix Sunscreen by Topix,
Acne Prone Skin
Those with frequent skin allergies may react to sunscreens due to the high incidence of allergies to sunscreen ingredients. Avoiding products with the chemical UV filters PABA, benzophenone and avobenzone can help; they can all irritate skin and lead to acne flare-ups. Physical blocking sunscreens micronized zinc oxide or titanium dioxide are a better choice - try Clinique Derma White Super City Block SPF 40, Blue Lizard for Sensitive Skin, Vanicream or Olay Complete Defense Daily UV Moisturizer SPF 30. People with darker skin should choose a tinted sunscreen to avoid the chalky, violet cast that physical sunblocks can cause. Quintessence Sunshade SPF 30 and Abella ColorShade SPF 30 are good options. In addition, avoid any products with cocoa butter or coconut oil, which can cause breakouts. (Note that many lip balm sunscreen have coconut oil and can give you pimples around the mouth).
Click here to shop for sunscreen products
Dry Skin
Those with dry skin should also take special care to avoid sun exposure. UV rays inhibit the enzymes that produce skin's natural moisturizing factor that helps skin cells hold onto water. It also decreases levels of hyaluronic acid, which draws water into the skin and keeps it plump and hydrated. Sun exposure can leave skin extra dry and flaky; even worse, dry skin is particularly vulnerable to the sun-induced aging known as photoaging. Luckily, sunscreens are usually rich and moisturizing because active sunscreen ingredients are usually formulated with oil, so creamy sunscreen lotions will work well for those with dry skin. Using a daily moisturizing lotion on your body such as Aveeno Daily Moisturizing Lotion with SPF 15, MD Skincare Powerful Sun Protection SPF 45 Sunscreen Cream, or Juice Beauty Green Apple SPF 20 Antioxidant Body Moisturizer to help moisturize and protect from the sun.
For the face, my favorite sunscreen for VERY dry skin is Dove Proage Day Moisturizer SPF 15. For moderately dry to slightly dry skin, I like Korres Watermelon Sunscreen Face Cream SPF 20, Darphin SOLEIL PLAISIR Protective Face Cream SPF 30, M.D. Forte Total Daily Protector SPF, and Kiehls Abyssine Cream + SPF23.
If your skin is sensitive and prone to allergies or burning and stinging as well as dry, it might also react to benzohenones and avobenzone. Physical sunblocks like Mustela Moderate Protection Lotion SPF 25, Topix Glycolix Elite Sunscreen SPF 30, or Skinceuticals Physical UV Defense SPF 30 are a good choice.
Back to Top ^
How much sunscreen should you use?
 No matter what your skin type, you should always be sure to apply sunscreen properly and to use it on all exposed areas that can give away your age. I can almost always tell how old someone is just by looking at their hands, chest and neck - the neck is particularly problematic because there aren’t really any procedures that can turn back the clock once the damage is done.
It takes a lot more product than most people think. You should use a half teaspoon just to cover your face, and reapply every 90 minutes when you are in the sun. If you’re going to be in the sun for more than 15 minutes, you should apply sunscreen all over your body, even to areas that aren’t exposed to sunlight. Clothing doesn’t offer as much sun protection as you might expect. A t-shirt, for example, has an SPF of only 5. If you plan to be inside I the house or office all day, a daily application of SPF 15 in the morning should be sufficient. You only need to reapply later if you will have sun exposure for 15 minutes or more. Dusting the face with a SPF containing facial powder such as Philosophy Supernatural Air Brushed Canvas SPF can help boost sun protection during the day without ruining your make-up.
Back to Top ^
Is there any way to increase your sun tolerance from the inside out,
through diet or supplements?
There is some interesting new data suggesting that antioxidants found in food can have a preventative effect in protecting against sun damage. For example, lycopene, as found in cooked tomatoes and tomato paste, can help tame the harmful free radicals that damage skin. (To learn more about this see the newsletter that I wrote on antioxidants) Red wine, pomegranate juice, oregano, green tea and chocolate are also rich in antioxidants and might help increase your skin's natural protection against the sun. Luckily, these are also very tasty!
As far as supplements go, fern extract (polypodium leucotomos) sold by your pharmacist as the supplement Heliocare is a powerful antioxidant that has been shown to protect against UV damage. Vitamin C, Coenzyme Q10 and green tea extract can also be beneficial. However, none of these can replace sunscreen.
There is some research being done now on supplements to increase melanin production, your skin’s natural protection against the sun, but these are not yet proven to be safe. The fear is that they might cause melanocytes (the cells that make melanin) to turn into melanoma, or cancer.
Back to Top ^
Do topical antioxidant creams work?
Yes. Unlike physical sunblocks, which reflect light away from the body, chemical sunscreens absorb the sun's energy and hold it in the skin, and this energy can lead to damaging free radicals. Adding topical antioxidants to your regimen helps neutralize free radicals. Antioxidant creams should be applied twice a day, or 30 minutes before sun exposure. For dry skin types try Kiehl's Lycopene Facial Moisturizing Lotion, Eucerin Coenzyme Q10 Sensitive Skin Face cream, Aveeno Positively Ageless or Replenix CF cream. Non-sensitive skin types will like Prevage by Allergan or Revaleskin by Stiefel. Oily skin types will benefit from Skineuticals CE Ferulic and Replenix CF serum.
Back to Top ^
Are there any products that can soothe or repair skin after it?s
been exposed to the sun?
Any good moisturizer will help rehydrate your skin after it’s been dried out by the sun. Look for one that contains glycerin or stearic acid, like Cetaphil, Ponds, Vaseline or Dove. If you do end up with a burn, you can take an Advil (ibuprofen) or aspirin every four hours to bring down the inflammation and redness. An over-the-counter hydrocortisone cream may help sunburns heal as well.
To combat fine lines caused by sun damage, the only proven topical products are those that contain Vitamin C, such as Skinceuticals C E Ferulic, or retinol, which is derived from Vitamin A. Retinoids are available by prescription and can be found in less potent form in many over the counter products. Over the counter retinols include Philosophy Help Me or Replenix Retinol Smoothing Serum. For best results, you should combine them with a great nighttime moisturizer, such as Kinerase Ultra Rich Night Repair.
Back to Top ^
In summary:
- Avoid the sun when you can
- Use a SPF of 15 every day
- Sit under an umbrella
- Use sun protective clothing
- Use antioxidants and retinoids to mitigate the damage
Have a wonderful summer!
Dr. Leslie Baumann
Do you have a question? Come visit me at www.SkinTypeSolutions.com or
read my Yahoo blog at www.SkinGuru.com
|
