I don't drink
I am delighted to say, that without me saying anything my non drinking example is spreading throughout the office. In the small team of five I work in only one person now drinks and he is thinking of cutting down dramatically. Being surrounded by people saying how great they feel, how alert, and the obvious improvement it has in the work they do really does make a difference. One of my colleague who was notorious for his rose wine consumption even managed five days at a very boozy conference in the South of France and stayed sober the whole time. Showing by example is so much softer than trying to nag people to stop drinking - and it works!