Improvement in the antioxidant status of plasma and low-density lipoprotein in subjects receiving a red wine phenolics mixture

It is commonly accepted that oxidized low-density lipoprotein (ox-LDL) plays an important role in coronary heart disease (CHD) and etiologically related atherogenesis. Consumption of wine may contribute to the low risk of CHD in the Mediterranean population. These findings raise the question of the in vivo antioxidant role of wine phenolic compounds after a prolonged supplementation period in healthy human volunteers. We found that subjects, receiving 2 g/d of an alcohol-free red wine-extracted phenolic compound (RWPC) mixture for 14 d (which was equivalent to about 1 L/d of the red wine), exhibited an increase in the plasma antioxidative capacity and in LDL vitamin E by blood sampling under fasting conditions. The fact that the LDL Cu²⁺-oxidizability was not decreased can be explained by both the lack of phenolic compound affinity for the lipoprotein particle, highlighted by LDL dialysis, and the insufficient increase in LDL vitamin E, as shown by the relationship between vitamin E content and oxidation resistance of LDL evidenced by literature data. These results support that RWPC could play a coantioxidant role, similar to that of vitamin C, possibly accounting for their LDL vitamin E sparing effect and their beneficial role in lowering CHD risks.