Changes of the redox balance are reflected at the blood level in old agers--chronically intoxicated with alcohol--presenting degenerative psycho-organic syndromes (DPOS). The parameters investigated were lipid peroxidation reduced glutathione and the total SH groups. The changes of the antioxidant enzymatic system expressed by the activity of superoxide dysmutase, of glutathione peroxidase and of catalase were also followed up. It was observed that compared with the control group the lipid peroxides increased by 70.69% and the blood concentration of G-SH and of the total SH groups decreased by 46.7% and 24.76%, respectively. Likewise enzymes such as GPx and CAT presented increases of 70.4% and respectively 68.3% associated with a decrease of 23.9% of SOD activity.