The components of red wine are well studied, and when combined, demonstrate a variety of health benefits involving the cardiovascular, immune and nervous systems. White wine, which is made without the skins, demonstrates far fewer benefits. Grape juice may contain as many beneficial compounds as red wine, depending greatly on its production, but without the alcohol content. Alcohol inhibits platelet cell clotting, which is desirable for people with certain conditions, but overall it is considered to impact health negatively.
Many of the studies supporting the benefits of red wine and grape juice involve compounds known as polyphenols, which are strong antioxidants able to scavenge free radicals and protect the deterioration of blood vessels and aging of other tissues. A main group of polyphenols found in grapes are flavonoids, which are present in red wine and some varieties of grape juice as proanthocyanidins. Grape seeds are the richest source of proanthocyanidins and are often crushed in the process of making red wine. Whether they are present in grape juice in significant amounts depends on the type of grape used and the method of production. Juice based on seedless grapes has little-to-no proanthocyanidin content. In addition to antioxidant behavior, proanthocyanidins also display anti-inflammatory and antihistamine properties, which offer protection against cardiovascular diseases, as cited in Medical Nutrition and Disease.
Resveratrol is another type of polyphenol found in dark-colored grapes, particularly within the skins. Resveratrol is a powerful antioxidant able to prevent fatty blockages and blood clots in arteries, inhibit bacterial and fungi growth, reduce inflammation and promote neuron growth in the brain, according to the Linus Pauling Institute. Red wine is the richest source of resveratrol because its production often involves fermenting all parts of the grape together, such as the skin, seeds, leaves and vines, which all contain resveratrol. Red wine contains between 0.2 and 5.8 mg/L of resveratrol, depending on grape type and aging, whereas white wine contains much less. Good quality organic grape juice made from red or purple grapes with seeds may contain as much resveratrol as some red wines but likely not as much as most.
Tannins and lignans are other types of polyphenols in grapes, which display antioxidant and other beneficial properties. Tannins are astringent compounds that give red wine and some grape juices their dryness and causes a puckering sensation in the mouth. Tannins are effective against diarrhea, stomach upset, inflammation and some microbes. Lignans are derived from wood and give some red wines their woody aftertaste, although the wood kegs in which they are stored affect taste also. Again, the amount of tannins and lignans in red wine and grape juice is highly variable but often much higher in wine, especially bottles that are aged, according to Contemporary Nutrition.
Most red wines contain about 10 percent alcohol, although some contain as high as 14 percent. Despite being able to reduce the “stickiness” of blood platelet cells involved in clotting, most health experts agree that alcohol cannot be considered healthy. Alcohol has a depressant affect on the brain; it reduces cognitive function and coordination; its breakdown products are toxic, and are especially harmful to the liver, pancreas and nerves; and it is habit forming. As such, the negative health consequences of alcohol may greatly negate the benefits of red wine, which means that high quality grape juice made by crushing dark-colored grapes with seeds may offer more health benefits overall.
- Biochemical, Physiological and Molecular Aspects of Human Nutrition; Martha Stipanuk
- Medical Nutrition and Disease: A Case-based Approach; Lisa Hark
- Linus Pauling Institute: Oregon State University: Resveratrol
- Nutritional Sciences; Michelle McGuire
- Contemporary Nutrition; Gordon M. Wardlaw
- Nutrition and Public Health; Sari Edelstein
- red wine image by jimcox40 from Fotolia.com
This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.