The increase in human plasma antioxidant capacity after red wine consumption is due to both plasma urate and wine polyphenols.

By using red wine, dealcoholized red wine, polyphenols-stripped red wine, ethanol-water solution and water, the role of wine polyphenols and induction of plasma urate elevation on plasma antioxidant capacity was examined in humans (n=9 per beverage). Healthy males randomly consumed each beverage in a cross-over design. Plasma antioxidant capacity (measured by ferric reducing antioxidant power, FRAP), ethanol, catechin and urate concentrations were determined before and 30, 60, 90, 120 and 180 min after beverage intake. Dealcoholized red wine and polyphenols-stripped red wine induced similar increase in FRAP values which represented nearly half the effect of the original red wine. This indicates that consumption of red wine involves two separate mechanisms in elevation of plasma FRAP values and both wine phenols and plasma urate contribute to that effect.