Red wine's health benefits come from tannin
Pretty much everything in wine that’s not alcohol or water is a type of polyphenol. Polyphenols include tannin, color pigment, wine aromas, resveratrol, and about 5,000 other plant compounds. Of these polyphenols, the most abundant in wine for health reasons are Procyanidins, which are a type of condensed tannin also found in green tea and dark chocolate. This compound is specifically associated with inhibiting cholesterol plaque in blood vessels, which is highly beneficial to heart health and longevity.