An anthocyanin/polyphenolic-rich fruit juice reduces oxidative DNA damage and increases glutathione level in healthy probands

Oxidative cell damage is involved in the pathogenesis of atherosclerosis, cancer, diabetes and other diseases. Uptake of fruit juice with especially high content of antioxidant flavonoids/polyphenols, might reduce oxidative cell damage. Therefore, an intervention study was performed with a red mixed berry juice [trolox equivalent antioxidative capacity (TEAC): 19.1 mmol/L trolox] and a corresponding polyphenol‐depleted juice (polyphenols largely removed, TEAC 2.4 mmol/L trolox), serving as control. After a 3‐week run‐in period, 18 male probands daily consumed 700 mL juice, and 9 consumed control juice, in a 4‐week intervention, followed by a 3‐week wash‐out. Samples were collected weekly to analyze DNA damage (comet assay), lipid peroxidation (plasma malondialdehyde: HPLC/fluorescence; urinary isoprostanes: GC‐MS), blood glutathione (photometrically), DNA‐binding activity of nuclear factor‐κB (ELISA) and plasma carotenoid/α‐tocopherol levels (HPLC‐DAD). During intervention with the fruit juice, a decrease of oxidative DNA damage (p