ALL ABOUT TANNING: INDOOR, OUTDOOR and SUNLESS TANNING!

All About TANNING: Indoor , Outdoor and Sunless Tanning!

(photo credit: www.amazon.com)

*by: Ghadah Abdulaziz


Sun exposure is beneficial in moderation, but can be harmful in excess. Every year, millions of people climb in various states of undress into warm, glowing tanning beds, where during a typical 2- to 15-minute session they’ll absorb a controlled dose of ultraviolet (UV) radiation at an intensity up to two to three times stronger than the sunlight striking the equator at noon.

  • Health benefits of  Tanning: 

Several health benefit claims such as improved appearance, enhanced mood, and increased vitamin D levels have been attributed to tanning. Furthermore, the Indoor Tanning Association claims that “catching some rays may lengthen your life”. A report on the tanning attitudes of young adults found that 81% of individuals in 2007 felt that a tan improved appearance, whereas only 58% of individuals in 1968 held the same belief.                                     

  •  Health risks

UV radiation promotes skin malignancies like basal cell carcinoma, squamous cell carcinoma, and melanoma, the most serious of these cancers, the association for each type of skin cancer differs.Intermittent sun exposure and sunburns were positively associated with melanoma, while, chronic sun exposure was not. A detailed review of case-control studies showed that cumulative sun exposure was associated with both BCCs and SCCs, whereas intermittent sun exposure was associated with only BCCs. A history of sunburn increased the risk for developing both BCCs and SCCs. Childhood sunburns were associated with SCCs, whereas sunburns at any age were associated with BCCs. Indoor tanning was associated with SCC but not BCCs. Frequent exposure to sunlight also accelerates skin aging. Much of this aging process has been attributed to UV exposure and subsequent free radical generation, with infrared radiation (IR) playing an important role. IR likely promotes photo aging by inducing the breakdown of collagen and increasing the presence of reactive oxygen species. Physical sun-blocking agents, like titanium dioxide, block infrared radiation ; but most chemical based sunblock’s were developed for UV, not infrared, photo protection. 

  • Role of the Indoor Tanning

Indoor tanning increases the risk of skin cancer, augments the risk for sunburn, and accelerates photo aging. Interestingly, indoor tanning practices are greatly influenced by parental acceptance and peer participation. It also increases the risk for developing skin cancer by 74% and it exposes users to two types of UV rays, UVA and UVB. Some scientists describe UVB as a “complete human carcinogen” because of its ability to cause direct DNA damage. UVA, on the other hand, is carcinogenic by an indirect mechanism: It’s involved in the production of DNA-damaging free radicals, such as hydrogen peroxide.      

  • Sunless Tanning

An alternative to UV tanning is sunless tanning. Currently marketed sunless tanning agents include spray-on tans and sunless tanning lotions. These products contain dihydroxyacetone (DHA), which reacts with the amino groups in the stratum corneum to stain the skin brown. DHA may temporarily increase the formation of UV radiation induced reactive oxygen species for the first 24 hours after application, leading to acceleration of sun induced damage. Therefore, minimization of sun and UV exposure following application of DHA is advised during the first 24 hours after application.  DHA based sunless tanning agents have a number of drawbacks. The effect is temporary, the resulting skin color can look unnatural, and there is an increased risk for sun-induced damage within 24 hours of application.


*
Medical Student
King Saud University
Riyadh, Saudi Arabia

References:                                                                                                                                                         http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2692214/                                                                       http://www.medscape.com/viewarticle/768721_2