['Oxidative stress has been linked to such degenerative diseases as atherosclerosis, and it has been suggested that increased dietary intake of antioxidants may reduce its progression.', 'To determine the effect of mandarin juice consumption on biomarkers related to oxidative stress in hypercholesterolemic children.', 'The diet of 48 children with plasma cholesterol >200 mg/dL and low-density lipoprotein cholesterol >130 mg/dL was supplemented for 28 days with 500 mL/day of pure (100%) mandarin juice (Citrus clementina Hort. ex Tan.). The composition of the mandarin juice was analyzed, and its antioxidant antiradical activity was evaluated in vitro. Malondialdehyde, carbonyl groups, vitamins E and C, erythrocyte-reduced glutathione, and plasma lipids were measured at the onset and at the end of the supplementation period. The paired Student t test was used to compare values before and after supplementation.', 'Mandarin juice exerted a strong antioxidant effect mainly due to its high hydroxyl activity and, to a lesser extent, to its superoxide scavenger activity. At the end of the study, levels of the plasma biomarkers of oxidative stress were significantly decreased (malondialdehyde -7.4%, carbonyl groups -29.1%, P < 0.01), whereas the plasma antioxidants vitamin E and C (13.5%, P < 0.001 and 68.2%, P < 0.00001, respectively) and intraerythrocyte glutathione level (36.7%, P < 0.00001) were significantly increased. Plasma lipids and antibodies to oxidized low-density lipoproteins remained unchanged.'] Does mandarin juice improve the antioxidant status of hypercholesterolemic children?