Answer to Question 1
Such differences may be due to the polyphenols found in wine that are especially high in red wine given that its red color is due to the skin of the grapes being used in the fermentation process where these compounds are especially concentrated. Along with the polyphenols, the plant hormone resveratrol, a vasodilator and antioxidant found in high concentrations in red wine is believed to play a health protective role by some experts. Therefore, red wine, in particular, is believed by some to have health advantages over other types of alcoholic beverages, including white wine.
Answer to Question 2
Antioxidants are chemicals found in particular vitamins, minerals, and phytochemicals that reduce oxidative stress. Oxidative stress refers to the adverse effects of oxygen free radicals on our cells primarily from byproducts of normal cellular metabolism. Our cells have their own natural antioxidants in the form of, for example, superoxide dismutase (SOD) that neutralizes most free radicals, but as we age there is indirect evidence that our cellular defenses against oxidative stress begin to slip exposing us to greater oxidative stress damage and vulnerability to the diseases of aging such as cancer and heart disease. In theory when free radicals damage cells, they may also contribute to potential anomalies of the cell or its DNA that increase the chance of normal cells prematurely aging or mutating into cancer cells.