Comparison of the effects of paired organic and conventional wines with different total polyphenol concentrations on plasma antioxidant status

Dietary polyphenols are ubiquitous phytochemicals with antioxidant activity, which may reduce the risk of chronic diseases. Organically grown plants, i.e., grapevines, with greater pathogen exposure may have even higher levels of polyphenols, e.g., resveratrol, than conventionally grown plants, which could increase plasma antioxidant capacity in humans without affecting sensory qualities. To test this, we randomized 18 females (21–50 y) to 1 of 5 groups each assigned a geographically paired organic (OW) and conventional wine (CW), and a placebo (PW) wine. At 3 independent visits and after a baseline blood draw for each, participants consumed 5 oz of 1 wine of the 3 within 15 min followed by a blood draw at 30 min post‐consumption. Total polyphenol (TP) concentrations, antioxidant capacity, i.e., FRAP, and sensory surveys were determined and collected. Results demonstrated that in 2 pairings the OW had significantly higher concentrations of TP (3.49, 5.8 g/L) vs. CW (2.63, 4.63 g/L). In 2 pairings, TP in CW was higher (5.23, 8.38 g/L) vs. OW (4.55, 3.70 g/L). The mean of the PW was 1.26±0.20. No significant differences in antioxidant capacity of plasma or sensory qualities were demonstrated between OW and CW. We conclude that OW and CW produced in the same vineyards in the SW US have similar antioxidant capacities even with significantly different TP concentrations.