In the biochemistry class during my naive undergraduate years, the professor jokingly said the capability of metabolizing alcohol depends on our genetic makeup. Thanks to the variations in the genes, some people can produce more enzymes or more active enzymes to take care of alcohol in their body. They can be heavy drinkers, or the ones less susceptible to the hazards caused by alcoholism than their fellow drunks.
That may explain the existence of Charles Bukowski (1920-1994), the "laureate of American lowlifes" who lived a relatively long life despite many days and nights of bottles and women at the bars. As Stephen King says in his insightful book "On Writing," writing usually has no business with drinking ("Hemingway and Fitzgerald didn't drink because they were creative, alienated, or morally weak. They drank because it's what alkies are wired up to do."). Sometime there are exceptions like Bukowski. Drinking and writing always came together to him, and he had no problem with that.