The fact remains, alcohol slows the thought processes, reflexes, and judgement. After a relatively small amount is consumed, it also negatively affects the balance and eyesight. It also dehydrates the body. Grape juice, without alcohol, has much of the same antioxodant properties. It doesn't dehydrate. Caffiene dehydrates, but has some effects of clarifying the thought processes and for a short period improving attention span and reflexes. The end result is that alcohol doesn't mix with driving, boating and flying.
A year or 2 ago, there was a study that said red wine is good for the cardivascular system. Most news commentary did not include the findings that ONE 4 ounce glass of red wine a day had a positive effect, two showed almost no increase, and by the third glass, the benefits went away. More was not better.