Wine contains phenolic compounds (polyphenols) which give wine its characteristic colour and flavour.
Phenolic compounds
Wine contains phenolic compounds (polyphenols) which give wine its characteristic colour and flavour and are produced by plants in response to fungal infection, ultraviolet light, and various chemical and physical stressors, especially during ripening. They are extracted from the seeds and skins of grapes during fermentation of winemaking, when the juice is in contact with the grape skins and seeds. The amount of polyphenols in red wine is generally greater than white wine because the red juice has longer contact with the grape skins during fermentation enabling more phenolic substances to be extracted into the red juice.
There is evidence that polyphenols can have beneficial effect on human health. The following properties of wine phenols have been shown:
They have antioxidant, neuroprotective and anti-inflammatory effects,
They normalise blood sugar,
They improve vascular endothelial function and
They inhibit platelet aggregation.
Resveratrol is one of the best studied wine ingredients. Together with other polyphenols (anthocyanins, flavanols and catechins) and their metabolites, it plays a special role in many of the cardio-vascular protective effects of moderate wine consumption. However, it is absorbed into the blood only to a small extent. Its vasoprotective effect also occurs directly by influencing the intestinal microbiota.
Researchers have shown that these polyphenols in wine act as antioxidants and are five times more potent than the benchmark antioxidant, vitamin E. These antioxidants are believed to reduce the damage caused by the body’s free radicals (toxic waste products) which contribute to causing degenerative diseases in the body such as cancer, Alzheimer’s disease, Parkinson’s disease, and ageing.
The wine polyphenols may also aid in inhibiting the oxidative transformation of ‘bad’ LDL cholesterol and thus, preventing the accumulation of this oxidised LDL cholesterol in the artery wall which eventually could block the blood flow and cause a heart attack or stroke. Generally, these wine polyphenols are not easily absorbed by the body, however, their metabolites might be the real key players in cardiovascular and cancer protection.
The many wine phenols cannot be considered individually with regard to their positive effects. It seems that they act synergistically and unfold their effects in combination with the alcohol. These findings support the overwhelming and still growing body of scientific research indicating that moderate consumption of wine/alcoholic beverages is associated with lower levels of coronary heart disease as well as with better health and lower mortality, especially when consumed in combination with a healthy diet.
