If smelling like awesome, having brass balls, and being able to crush ass like Wilt Chamberlain are all health problems, then yes it's true. Who told you that?
In all seriousness, I've never heard that before. There has been on and off interest from the medical community through the years. In fact, I've flown with Dosimeters (measures radiation exposure) and to my knowledge the readings weren't much different than that experienced on the ground or lower altitudes...or maybe they just didn't tell me. With 50+ years of flying, you'd think there would be more than rumors if there was any truth to it.
925 huh? Go Badgers!