A research group is proposing that buildup of advanced glycation end-products (AGEs) causes DNA damage in addition to known other issues: "The scientists studied semen samples from men with diabetes who were receiving insulin therapy. ... when we looked for DNA damage, we saw a very different picture. Sperm RNA was significantly altered, and many of the changes we observed are in RNA transcripts involved in DNA repair. ... Diabetics have a significant decrease in their ability to repair sperm DNA, and once this is damaged it cannot be restored ... We found a class of compounds known as advanced glycation end products (AGEs) in the male reproductive tract. These [accumulate] during normal ageing. They are dependent on life style - diet, smoking etc - and in many diabetic complications are centrally implicated in DNA damage. ... The scientists intend to follow up their work by trying to determine how AGEs cause and contribute to DNA damage. They believe that they may have uncovered a new role for AGEs, and that their influence goes far beyond diabetes and its complications." I think that this is proposed on a fairly weak correlation, but we'll see where it goes.