Excessive alcohol consumption in all forms including wine has very bad effects on human health. But a moderate consumption of alcohol especially in the form of wine has been found to be beneficial for health.
There are many chemicals in found in wine which are beneficial for the body. This includes polyphenols which have been found to reduce the incidence of heart disease. A chemical called resveratrol has been found to have anti aging properties in mice. These protect against cancers and many illnesses that result from old age. Other beneficial compounds in wine include other polyphenols, antioxidants, and flavonoids.
Wine consumption by people in the Mediterranean and France has been correlated to their good health in spite of consuming other food that is generally high in saturated fats and bad for health.