Cosmic Radiation Speeds up Aging in Space?

SpaceAdmiral writes "The Theory of Relativity tells us that the faster a person travels the slower time passes for that person relative to someone left on Earth. This means that traveling at high velocities in a spacecraft should reduce one's aging. However, recent research suggests that cosmic radiation may counteract that anti-aging effect. Iron-nuclei radiation affects the aging of cells, which is possibly one of the reasons astronauts who have been to the Moon tend to get cataracts about 7 years earlier than other astronauts."