Dr. Leroy Creasy, a wine researcher and professor emeritus at Cornell University in Ithaca, N.Y., said anthocyanins -- plant-derived antioxidants -- create the red color in wine and darker red wines contain higher amounts, Men's Health reported.
The color in wine comes from the grape skins that remain in the tank as the wine ferments. Skins also provide resveratrol, an antioxidant that can reduce heart inflammation and reduce the risk of heart disease.
However, some reds have more antioxidants than others.
Dr. James Harbertson, an enologist at Washington State University, suggested buying wine grown in sunny vineyards.
The theory is that grapes produce more antioxidants when exposed to ultraviolet light -- "the farther from the equator, the more daylight hours you have," Harbertson said.