The connection between wine and cholesterol centers on two antioxidants and a plant compound found in grapes. Wine and cholesterol have been the focus of several research projects to determine if wine might naturally lower cholesterol. Some evidence shows wine, particularly red wine, might reduce harmful cholesterol levels if consumed regularly.
Saponins are glucose-based compounds found in the waxy coating of grape skins. Wines made with skins intact retain saponins, which might bind to cholesterol and prevent absorption by the body. Studies reveal the connection between red wine and cholesterol might result in a slight decrease in the level of low-density lipoprotein, commonly called bad cholesterol. One glass of red wine provides about half the total daily recommended intake of saponins, also found in olive oil and soybeans.
Another link between wine and cholesterol involves two antioxidants found in the beverage. Resveratrol represents a natural chemical in grapes that fights fungi in damp growing regions. The amount of resveratrol in wine varies with the type of grape, where it grows, and the process used to produce wine. Wine-making techniques using filters to reduce bitterness remove much of the resveratrol. The skins are removed to ferment white wine, removing most of the resveratrol.
Mass-produced wines typically go through additional filtering because they are not allowed to age. Studies show resveratrol blocks the oxidation of cholesterol, and might be as effective as saponins in reducing bad cholesterol. Resveratrol also prevents platelets in the blood from clotting and might raise levels of high-density lipoprotein, considered good cholesterol.
Flavonoids describe the second antioxidant examined in wine and cholesterol studies. Flavonoids work like resveratrol in preventing bad cholesterol from oxidation. Apples, grape juice, and green tea also contain flavonoids and resveratrol in varying amounts.
After the connection between wine and cholesterol surfaced, scientists conducted experiments to learn which wines contain the highest amounts of the chemicals. They found pinot noir grapes grown in wet, cool regions in France contained the most resveratrol, perhaps because grapes are more prone to rot in this climate. A similar study of American wines found the highest levels in red zinfandel. Levels of the antioxidant might vary by weather conditions each year.
These studies also found the level of resveratrol begins declining within 24 hours after wine is opened. Most heart specialists advise against excessive drinking to improve health, and recommend limiting alcohol consumption to one serving a day. They commonly suggest using exercise, diet, and medication to lower harmful cholesterol levels. Niacin supplements and aspirin might provide the same anti-clotting benefits as resveratrol.