UVA Protection as an Anti-aging Strategy: a ten point information guide
(the following facts are summarized from an article by Sheldon R. Pinnell, MD and Doren L. Madey, PhD, which appeared in the peer-reviewed Aesthetic Surgery Journal May/June 1999)
1) UVA is relatively (RELATIVE TO WHAT) more constant throughout the year, even penetrating glass, and subjecting us to exposure at home, work, and in the car. Scientists believe that 90% of perceived skin aging--including wrinkles, roughness, mottled pigmentation and loss of skin tone--is due to broad-spectrum ultraviolet damage. SO, BROAD SPECTRUM IS UVA B AND C, RIGHT. I FEEL LIKE THIS FIRST POINT NEEDS A LITTLE CLARIFICATION
2) Recently, scientists have proven that ultraviolet A (UVA) radiation is a major culprit in photoaging and skin cancers. Unfortunately, most sunscreens don't protect against long-wave UVA. UVA rays, which penetrate deep into skin, are responsible for elastic tissue damage and photoaging, and are thought to be important in causing more aggressive skin cancers, including deadly melanomas. I MIGHT EVEN CONSIDER LISTING THIS POINT FIRST. THIS ESTABLISHES WHAT UVA RAYS ARE, WHY THEY ARE DANGEROUSE, ETC. THEN THE POINT ABOVE DRIVES HOME THE IDEA THAT THEY ARE ESP. DANGEROUS BC THEY ARE PRESENT YEAR ROUND.
3) One study involving the irradiation of human skin shows that it takes only eight modest doses of UVA exposure to cause photoaging and that these changes occur before any sunburn or tanning is evident. In this study, a modest dose was defined as 1 hour of summer midday sun. Thus, if the sunscreen [has a high SPF rating] but does not include a UVA protector, you will be exposed to even more UVA damage--and without ever burning!
4) Today, most sunscreen products provide UVB and partial UVA protection. Common UVB sunscreen ingredients include octyl methoxycinnamate (OMC), octocrylene, octyl salicylate (OCS), octyl dimethyl paba (PABA). The most common short-wave UVA ingredient is oxybenzone (benzophenone-3). Titanium dioxide primarily provides protection against UVB and short-wave UVA, but not long-wave UVA.
5) Only two sunscreen ingredients available in the United States--a chemical ingredient, avobenzone, and the physical ingredient, zinc oxide--provide protection against long UVA rays. But only one--zinc oxide--provides comprehensive protection against UVB and both short and long UVA radiation.
6) Avobenzone, also known as Parsol 1789, is a chemical sunscreen agent that is absorbed through the epidermis. One recently published in vitro study shows that avobenzone degrades in the presence of sunlight and is rendered ineffective within just 1 hour. Avobenzone also has been shown to degrade other sunscreen ingredients, with which it is combined, including the most common UVB ingredient, OMC, and a common short UVA block, oxybenzone.
7) Patients often think that zinc oxide and titanium dioxide provide equally good photoprotection, but this is not true. Although both agents are inorganic sunscreens that have now been produced in microfine form, they provide different levels of photoprotection. Microfine titanium dioxide effectively attenuates UVB and short-wave UVA; however, it is much less effective than zinc oxide in protecting against long-wave UVA. In addition, titanium dioxide has a higher refractive index in visible light than zinc oxide. Therefore, titanium dioxide is whiter and more difficult to incorporate into transparent products.
8) Zinc oxide is the closest thing to a total sunblock on the market today. It uniformly covers from 290 to 400 nm, thus protecting against the UVB and UVA spectrum. No other sunscreen ingredient provides broader protection. And unlike many chemical sunscreen agents, zinc oxide is never irritating. In fact, it is recognized by the Food and Drug Administration as a Category I skin protectant, meaning that it is safe for compromised or environmentally challenged skin. Zinc oxide has over a 300-year history of safety, with no known adverse reactions (which is why it is often used to treat babies). Now, in its microfine form, it is ideal for use in sunscreens and daily moisturizers.
9) The gold standard for protection against UVB and both short- and long-wave UVA is microfine zinc oxide, which is now available in both daily wear and beach products. Because current federal regulations allow sunscreens and daily moisturizers with sun protection to be labeled "broad spectrum" even if they provide only partial UVA protection, consumers must look for zinc oxide as a key active ingredient. Higher concentrations of microfine zinc oxide offer greater protection, so consumers should also determine the percentage of microfine zinc oxide in the product. (see “Microns, Nanoparticles and Products Specs)
10) New evidence also indicates that topical vitamin C is a useful adjunct to sunscreens. This powerful anti-oxidant naturally protects skin by neutralizing damaging free radicals. When applied topically in a concentrated, stable form that the body can use (L-ascorbic acid), it is possible to target vitamin C directly to the skin, thereby providing additional protection against UVB, UVA and pollutants. (see Vitamin C Delivery below)
(The above information was taken from an article by Sheldon R. Pinnell, MD and Doren L. Madey, PhD, appearing in the peer-reviewed May/June 1999 Aesthetic Surgery Journal. To read the entire article please go to: http://www.washingtonfacelift.com/asaps_sun_protection_article.html)
Vitamin C Delivery
Vitamin C protects against future sun damage and helps repair existing photo-damage as long as it meets the following criteria:
- type of vitamin C—must be l-ascorbic acid (for its ability to neutralize the hydroxyl radical)
- high percentage concentration (10% and over)
Marie Veronique Organics’ powdered supplements meet all the criteria They:
- use L-ascorbic acid in powder form
- are stable because you add the powder fresh each time, so it does not have a chance to oxidize in liquid
- are in a concentration of 10% or more (when added fresh the concentration of solute to solution is 20-30%, and, since you control the mixture, the concentration can be even higher)