Oxidative stress, and iron and antioxidant status in elderly men: differences between the Mediterranean south (Crete) and northern Europe (Zutphen)

Abstract

Background Oxidative stress may accelerate ageing and increase the risk of chronic diseases, such as coronary heart disease (CHD). We assessed differences in oxidative stress, and iron and antioxidant status between elderly men living in Mediterranean southern Europe (Crete, Greece) and northern Europe (Zutphen, The Netherlands). Design A cross-sectional study using data from two cohorts of the Seven Countries Study. Methods Non-fasting blood samples were drawn in 2000 from 105 men from Crete and 139 men from Zutphen, all aged 79 years or over. All assays were performed in the same laboratory. Results After multiple adjustments, serum levels of the markers of oxidative stress were lower in Cretan men than in men from Zutphen, as indicated by lower mean levels of hydroperoxides (33.2 versus 57.3 μmol/l; P = 0.005) and gamma-glutamyltransferase (20.3 versus 26.1 U/I; P = 0.003). The most pronounced difference in iron status was a twofold lower mean serum ferritin level in Cretan men (69.8 μg/I) compared with men from Zutphen (134.2 μg/I; P < 0.0001). Men from Crete had consistently higher plasma levels of major plasma antioxidants than the Zutphen men, including a nearly fourfold higher mean level of lycopene (15.3 versus 4.1 μg/100 ml; P < 0.0001). Conclusion Elderly men from Crete had consistently lower levels of the indicators of oxidative stress and iron status and higher concentrations of major antioxidants than men from Zutphen. These differences may contribute to the lower rate of CHD and total mortality that has been observed in this cohort of Cretan men.