Background: Red wine consumption is associated with reduced cardiovascular disease mortality. Its cardioprotective properties may be partly related to its ability to improve endothelial function. The purpose of this randomized controlled cross-over study was to determine whether moderate doses of red wine and de-alcoholized red wine improve coronary flow velocity reserve (CFR).
Methods: Using transthoracic Doppler echocardiography, 176 CFR measurements were made in 22 healthy men before and after ingestion of a moderate (4.0+/-0.4 dl) and an escalating high dose (total amount 8.1+/-0.9 dl) of alcohol-containing red wine and de-alcoholized red wine, which contained similar amounts of phenolic substances. The difference in plasma antioxidant capacity was determined by colorimetric assay kit.
Results: Red wine increased CFR from 3.8+/-1.4 to 4.5+/-1.4 (p<0.01) and 4.0+/-1.2 (p=NS) after moderate and high doses, respectively; whereas de-alcoholized red wine had no significant effects on CFR (4.0+/-0.7, 4.3+/-1.3 and 4.5+/-1.4, respectively). Plasma antioxidant capacity increased significantly after high dose of red wine (27.5+/-14.7%, p<0.001), but not after de-alcoholized red wine (0.5+/-10.5%, p=NS) despite similar amounts of phenolic substances. Differences between CFR and plasma antioxidant capacities before and after drinking had no significant association.
Conclusions: A moderate dose of red wine, but not de-alcoholized red wine increases CFR. The increase of CFR is probably mediated by other than direct antioxidant properties of polyphenols, because the simultaneous increase of CFR and plasma antioxidant capacity were not associated.