Changes in plasma antioxidant capacity and oxidized low-density lipoprotein levels in men after short-term cranberry juice consumption

Low-density lipoprotein (LDL) oxidation is closely implicated in the development of atherosclerotic cardiovascular disease (CVD), and thus, reducing LDL susceptibility to oxidation with antoxidants could be of importance in CVD prevention. Flavonoids, polyphenolic compounds found in a large selection of fruits and vegetables, have been characterized as having a strong antioxidant potential, and intake of flavonoid-rich foods has been related to decreased morbidity and mortality from heart disease. The present study was therefore undertaken to investigate the effect of flavonoid-rich cranberry juice supplementation on plasma lipoprotein levels and LDL oxidation. For that purpose, 21 men (age +/- SD, 38 +/- 8 years) were enrolled in a 14-day intervention and instructed to drink cranberry juice 7 mL/kg body weight per day. Physical and metabolic measures including plasma lipid and oxidized LDL (OxLDL) concentrations as well as antioxidant capacity were performed before and after the intervention. At baseline, we found that plasma OxLDL levels were significantly associated with waist circumference (r = 0.47, P =.0296) as well as plasma triglyceride (r = 0.68, P =.0007) and apolipoprotein B (r = 0.91, P <.0001) concentrations. The intervention led to a reduction in plasma OxLDL levels (-9.9% +/- 17.8%, P =.0131) and increase in antioxidant capacity (+6.5% +/- 10.3%, P =.0140). However, no relationship was found between both of these changes (r = -.01, not significant). The intervention did not result in any improvement of plasma lipoprotein-lipid or inflammatory marker concentrations. Our results show that short-term cranberry juice supplementation is associated with significant increase in plasma antioxidant capacity and reduction in circulating OxLDL concentrations. Although the physiological relevance of our observations needs to be further examined, our study supports the potential role of antioxidant-rich foods in maintaining health and preventing CVD. (c) 2005 Elsevier Inc. All rights reserved.