Polyphenols are antioxidant compounds found in the skin and seeds of grapes. When wine is made from these grapes, the alcohol produced by the fermentation process dissolves the polyphenols contained in the skin and seeds.
Red wine contains more polyphenols than white wine because the making of white wine requires the removal of the skins after the grapes are crushed. The phenols in red wine include catechin, gallic acid, and epicatechin.
Polyphenols have been found to have antioxidant properties. As well as being an antioxidant, resveratrol has been shown to reduce tumor incidence in animals by affecting one or more stages of cancer development (initiation, promotion and progression). It has been shown to inhibit growth of many types of cancer cells in culture. Evidence also exists that in can reduce inflammation; it also reduces activation of NF kappa B, a protein produced by the body's immune system when it is under attack.
Research on the antioxidants found in red wine has shown that they may help inhibit the development of certain cancers, but more research is needed as at the time of writing. Although consuming large amounts of alcohol may increase the risk of some cancers, there is growing evidence that the health benefits of red wine are related to its non-alcoholic components.
According to researchers in Spain, drinking wine – especially red – stops people from developing colds. The same effect was not observed with beer and spirits. The evidence comes from a year-long study of 4,000 volunteers. Experts at five universities found that people who drank more than two glasses of red wine per day had 44% fewer colds than teetotallers. Drinking one glass of red wine each day protected to a lesser extent.
Red wine has been associated with a number of health benefits, including a lower rate of heart disease.
Ingredients in red wine may also prevent herpes, according to a recent study.