As with everything else in life, all is OK in moderation
I think the impact of alcohol to us are any kind of bad things you can do.If you drunk for example you can do a things that happens are not good.Alcohol is bad or not bad, if you control this in your self.
Thr problem is that you can't control this yourself when you're already dead drunk. Sometimes you can do things that you normally don't. Some people even become violent when they're drunk. The point is that alcohol needs to be taken in small amounts, if you really can't avoid it. Many lives have been affected negatively by excessive alcohol consumption