Its effect would be mostly to shift color. Xenon gas will emit a certain level of UV light when flashed. Einstein has a UV coating on the tube to remove most of that UV light. Certain white textiles and papers have a tendancy to flouresce when exposed to UV light due to the brightener agents used in manufacturing and cleaning. Most people are familiar with how white shirts, socks, teeth, etc. can glow when you are under a black light. This is the same thing. By filtering the UV, you reduce or eliminate the flourescence. This is very important for Brides dresses or cheap softboxes/umbrellas from cheap vendors (and some not-so-cheap vendors) 
http://www.paulcbuff.com/plm-competitor.php. We ensure our fabrics are non-flourescing. 
Unless the same model was subjected to flashing for long periods (all day for days), there would not be any substative benefit to UV over non UV as far as health concerns, especially since the tubes are already coated.