Athletes that participate in outdoor activities are vulnerable to long term skin damage from ultraviolet radiation from the sun. Limiting outdoor training to early morning and late evening can help reduce sun exposure. Additionally, use of a high Sun Protection Factor (SPF) sunscreen, rated 15 or higher, is recommended to prevent skin damage. There are many different brands of sunscreens available, each with different active ingredients. Different active ingredients provide protection across different segments of the UV radiation spectrum. The optimum sunscreen for outdoor athletes should block both UVA and UVB rays. Blocking UVA rays will help prevent premature aging of the skin. Blocking UVB rays has been shown to decrease the incidence of certain skin lesions, such as Actinic Keratosis, and Squamous Cell Carcinoma.
Methods of Protection
Sunscreen ingredients are divided into two categories:
Chemical Absorbers – This class of sunscreen ingredients is composed of complex, “aromatic” compounds that absorb high energy UV rays, and convert them into lower energy, longer wavelength rays. The lower energy rays are not damaging to the skin.
Physical Blockers – This class of ingredients includes agents that are micronized, or reduced to nano-particles which reflect, rather than absorb, UV radiation.
UVB Radiation Chemical Absorbers
The following sunscreen ingredients effectively absorb UVB radiation:
Palmidate O (PABA derivative) – Para-aminobenzioc Acid was one of the first commercially available sunscreens and is the most effective UVB radiation absorber. However, adverse skin reactions and staining of clothing led to decreased use.
Octinoxate – Octinoxate is the second most powerful UVB absorber. It is also the most frequently used sunscreen ingredient currently. It has surpassed PABA derivatives due to fewer incidences of skin problems and clothes staining.
Octyl Salicylate - Octyl Salicylate, or Octisalate, is a weak UVB absorber with a good safety profile. It is generally used in combination with other agents in a sunscreen preparation.
UVA Radiation Chemical Absorbers
Avobenzone – Avobenzone, also known as Parsol, has been used throughout Europe for the last decade, and was recently approved for use in the United States. Parsol provides wide spectrum UVA protection.
Oxybenzone – Oxybenzone provides both wide spectrum UVA, and significant UVB radiation protection.
Ecamsule – Ecamsule, known by trade name Mexoryl, is also new to the United States. Mexoryl-containing sunscreens have been used for many years of use in Europe and Canada. Due to concerns about photostability, Mexoryl is combined with other ingredients in a product called Antihelios SX to increase effectiveness and stability.
Physical Blockers
Titanium Dioxide – Titanium dioxide is an inert particle that reflects UV radiation across the entire spectrum. The only objection to sunscreens containing titanium dioxide is aesthetic, as these creams leave a faint whitish film on the skin.
Zinc Oxide – This long time sun blocker was recently approved for use in sunscreen products by the FDA. Zinc Oxide has similar advantages and disadvantages to titanium dioxide, but may be slightly less whitening to the skin, and may provide slightly better UVA protection.
For more information: See “Sunscreens and Photoprotection” from eMedicine.com
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