As red wine contains resveratrol which is good for the heart (also contained in chocolate and berries) it can be seen as protective. It is a potent anti-oxidant plus a little glass of wine can also have benefits from it’s relaxing effect.
Alcohol flows through the blood stream and is metabolized by the liver, where the alcohol is broken down by enzymes.
The liver can, on average, metabolize about one standard drink (i.e. one 12 ounce bottle of beer, one 4 ounce glass of wine or 1.5 ounces of 40% alcohol) in one hour. Alcohol consumed in addition to these amounts can generally not be processed by the liver.
When this happens, your blood becomes saturated and the additional alcohol makes its way to your body tissues and blood stream, until your liver can process the excess alcohol.
So have your small glass along with a glass of water and there will be no dehydration effect.
(Resveratrol is produced in response to injury. It is a stilbenoid, a type of natural phenol, and a phytoalexin produced naturally by several plants when under attack by pathogens such as bacteria or fungi.)