Effects of Red Wine and Cognac on Coronary Circulation

Moderate consumption of red wine is associated with reduced coronary artery disease mortality. Cardioprotective effects of red wine may be partly related to its ability to improve endothelial function. Red wine increases endothelium-dependent flow-mediated dilatation of the brachial artery acutely after ingestion. Moreover, a heavy dose of red wine (ethanol 1.0 g/kg) has been shown to increase coronary flow reserve (CFR) as measured with transthoracic Doppler echocardiography. CFR depicts the relative increase of coronary blood flow in response to maximal myocardial hyperemia induced by adenosine. It is reduced in atherosclerosis and various conditions associated with the dysfunction of coronary microcirculation, such as diabetes and hypercholesterolemia.

Both ethanol and antioxidative polyphenols have been implicated in beneficial endothelial effects of red wine. However, their relative contributions remain uncertain in vivo. It has been suggested that red wine has stronger vasoactive properties than other alcohol beverages, and even de-alcoholized red wine may be sufficient to improve flow-mediated dilatation of the brachial artery. Cognac is also known to contain polyphenols, but its effects on coronary circulation have not been evaluated.

The purpose of this randomized controlled cross-over study was to determine with transthoracic echocardiography whether moderate doses of red wine improve CFR in response to adenosine in healthy humans. We also studied contributions of ethanol and antioxidants by comparing the effects of equal doses of alcoholic and de-alcoholized red wine, and cognac on the plasma antioxidant capacity and CFR.