What does nuclear DNA damage have to do with aging? The correlation is clearly there - older animals have more random nuclear DNA damage - but the mechanism by which increased damage might lead to some portion of degenerative aging is up for debate. A recent paper shows that the correlation extends to calorie restriction and some genetic manipulations that extend life: "Genetic instability has been implicated as a causal factor in cancer and aging. Caloric restriction (CR) and suppression of the somatotroph axis significantly increase life span in the mouse and reduce multiple symptoms of aging, including cancer. To test if in vivo spontaneous mutation frequency is reduced by such mechanisms, we crossed long-lived Ames dwarf mice with a C57BL/6J line [to] measure mutant frequencies. ... Four cohorts were studied: (1) ad lib wild-type; (2) CR wild-type; (3) ad lib dwarf; and (4) CR dwarf. ... results indicate that two major pro-longevity interventions in the mouse are associated with a reduced mutation frequency. This could be responsible, at least in part, for the enhanced longevity associated with Ames dwarfism and CR."

Link: http://www.ncbi.nlm.nih.gov/pubmed/18565572