when I was at work, I used to meet quite a few older well to do people whose working lives had been abroad, often in the tropics, where social drinking was a way of life and oiled the wheels of commerce. they wouldn't have said they drank a lot and I certainly never saw them out of control, but the empty gin bottles (it usually was gin, with vermouth early in the day and then with tonic or bitters) told their own story. and yes, "alzheimers" was often diagnosed.