Free Radic Res. 2007 Mar;41(3):324-8.

"Body iron is a contributor to oxidative damage of DNA."

Tuomainen TP, Lo et al.

The transition metal iron is catalytically highly active in vitro, and
not surprisingly, body iron has been suggested to promote oxidative
stress in vivo. In the current analysis we studied the association of
serum ferritin concentration and serum soluble transferrin receptor
concentration with daily urinary 8-hydroxydeoxyguanosine excretion, a
marker of oxidative stress, in 48 mildly dyslipidemic men in East
Finland. In multivariate linear regression analyses allowing for age,
smoking, body mass index and physical exercise, serum ferritin
concentration predicted the excretion rate at B = 0.17 (95% CI
0.08-0.26, P = 0.001), and serum soluble transferrin receptor to
ferritin concentration ratio (TfR/ferritin) predicted the excretion
rate at B = - 0.13 (95% CI - 0.21 to - 0.05, P = 0.002). Our data
suggest that body iron contributes to excess oxidative stress already
at non-iron overload concentrations in these subjects.