Red grape skin contains a powerful antioxidant called resveratrol, a polyphenol. Polyphenols are antioxidants that work to prevent cellular damage within the body. They are not essential for human nutrition but sufficient evidence is being gathered to support the notion that they play a significant role in attaining optimal health and even preventing disease.
It is polyphenols that give fruit and veg their colour, flavour, and even scent. Those that are brightly coloured, like grapes, are significantly high in these polyphenols.
Polyphenols within humans act as antioxidants, thereby helping to remove free radicals from the body. Free radicals damage cells, causing them to age (otherwise known as oxidative stress). It is said that Polyphenols slow the rate of oxidative stress as they stabilise free radical molecules. Resveratrol is a polyphenol found in red grape skins and red wine taken in supplemental form for its supposed life-extension benefits.
It is resveratrol that is produced by plants to help them defend themselves against attack from moulds and other pathogens. As a result of this, its presence in red grapes is relative to the moulds, yeasts and other environmental pressures that put forth an oxidising attack on the fruit. Cold, mouldy climate such as Bordeaux in France produces grapes with a high content of resveratrol, hence the well-known ‘French Paradox’ phrase which concerns itself with the fact that although those in France may have a diet high in saturates, mortality from coronary heart disease is relatively low there. This leads to the idea that a regular intake of red wine might provide further protection from cardiovascular disease as red wine contains resveratrol. Scientists believe resveratrol's ability to ward off oxidative damage is not limited to the grape itself but that it can do the same for those who consume it. And like an antioxidant, resveratrol protects cells from oxidative damage caused by free radicals. Ageing occurs as a result of oxidative damage caused by free-radical. This is why we age. It is believed that one way to help stay looking younger for longer is to take a resveratrol supplement as its antioxidant capability to minimise cell damage may help keep skin looking more youthful.