Bond did not really shows signs of excessive drinking in the novels until Goldfinger. We get his physical results in the beginning of Thunderball and we learn he drinks about a half bottle of 60 to 70 proof liquor a day and he drinks due to depression in You Only Live Twice. Remember YOLT was after On Her Majesty’s Secret Service.
I would not characterize his drinking as alcoholism. He doesn’t seem to have a problem while working.
I would also say there is a difference between a guy that likes to get drunk and an alcoholic. But I’m no expert on the subject.
Half a bottle a day sounds like a lot to me but I don’t know if it’s enough to seriously harm one’s life expectancy.