I don't have any first hand knowledge, only second hand experiences. My paternal grandfather struggled with heavy drinking for years after he left the army. He was verbally and sometimes physically abusive to my father and uncle. This alienated them from him, (more my father because he was older). Then my mother and father met, and she became pregnant with me. When my grandfather realized that he would be a first-time granddad, and my father said that he would never get to see me if he remained a drunk...he got sober. I always liked to hear my grandmother say that I saved the family

He hasn't taken a drink since about 4 months before I was born, and he is STILL after all these years, very active in AA.
My grandfather goes to meetings at least 1-2 times weekly, and some of his AA friends are actually like 2nd family members to us...even some that happen to be caucasian. When my grandfather was sick, they would sometimes come to his house and have meetings there. The comraderie is amazing.
My father and grandfather still have their issues, mainly because (although i love him dearly), my father is an ass. He's held onto all of the pain from his childhood, and they barely speak. Honestly, I think my father is trying so hard not to be like my grandfather, and he sees himself doing some of the same things and it just makes him angry. My grandfather sees my father doing some of the same things he did and he just gets disgusted. Hate/Hate relationship, you know? I've always wondered whether having a familial link to alcoholism would make you genetically predisposed to being more vulnerable to the bottle. It seems as though my father is 'indulging' himself more and more. Of course, when you call him on it...he is like, "I'm nothing like my father, I can handle my liquor, I can stop drinking anytime I want". Yeah, okay.