UVB is the main culprit for skin damage
the body finds harder to repair, according to scientists in the US.
The study, which appeared in the current issue of the journal of the Federation of American Societies for Experimental Biology (FASEB), points to the fact that both types of radiation illicit DNA damage, however the body finds it harder to repair that caused by UVB. This explains why UVB is more likely to cause skin cancer than UVA said the scientists led by Dr Ahmad Besaratinia at City of Hope National Medical Centre. "Our study is novel in that it fills the gaps in knowledge of mechanisms involved in sunlight-associated skin cancers, which cover various aspects of DNA damage and repair and genetic alterations," said Besaratinia. According to Editor in Chief of the FASEB journal Gerald Weissmann increased knowledge behind the body's repair mechanisms will be significant in the search for new effective sun care products and cancer prevention. "It forms a missing link in the chain of events from sun exposure to tumour formation. This research article gives us information that could lead to better sunscreens or effective 'after sun' products," Weissmann. UVA damage is more successfully repaired The team exposed cells to UVA light, UVB light and simulated sunlight and then compared them to an unexposed control group in order to assess the cell's repair mechanisms. According to the study the cells more successfully repaired damage caused by the UVA light than the UVB light. Currently a focus for manufacturers is improving the UVA protection of their products. Although scientists and health professionals emphasise the danger of the longer UVA wavelengths it is clear the shorter UVB rays should not be forgotten. UVB plays a role in ageing too Recent research published in Experimental Dermatology and sponsored by the American company AGI Dermatics also highlighted the significant role UVB plays in photoageing, a realm that has hitherto been associated with UVA. Although the UVB rays do not penetrate the skin so deeply they lead to damage in the deeper layers of the skin. "The sunlight triggers the release of enzymes in the top layer of the skin which then travel to the lower layers and do the damage," explained AGI Dermatics scientist Daniel B Yarosh. According to Yarosh, the recent focus on UVA protection has led to improved protection in suncare products however we should not forget the significant role UVB plays in the affair. "For competitive reasons manufacturers started concentrating on UVA protection as most products had a similar level of UVB protection" he explained.