There are approximately 125 calories in a single 5-fluid-ounce glass of wine. Alcoholic beverages such as wine are considered empty calories, meaning they have very little nutritional value.
While red wine is considered to be low in most nutrients, there is evidence that the antioxidants present in wine may provide some health benefits. Red wine contains both flavonoids and nonflavonoids, two compounds shown to prevent heart disease by raising the levels of good cholesterol in the body. Grape skins contain nonflavonoids that may reduce blood clots, which contribute to stroke and heart attack. Red wine is produced by crushing red grapes and employing yeast to consume the sugars present in the grapes.