With apologies to the real Puritans- who actually enjoyed a good drink in moderation- the tendency to be what people call “puritanical” about alcohol is a peculiar type of delusional thinking. Why do I say delusional? Because aggressively sober people are absolutely convinced that avoiding alcohol is healthier and cleaner, in the absence of overwhelming and consistent evidence to the contrary.
Many people are aware of the theory that alcohol led directly to the creation of the first agricultural civilizations (due to the need to stay in one place to cultivate grains for fermentation). Many people are also aware that it was safer in Medieval times to drink alcohol than to drink the contaminated water. However, there is now a substantial body of evidence that completely abstaining from alcohol is one of the least healthy choices you can possibly make.
The reasons for this are unclear and probably very complex, but they don't just apply to moderate drinking. People who enjoy between one and three drinks a day have the lowest rates of mortality from all causes combined, but second place doesn't go to the teetotalers. It goes to the heavy drinkers, who somehow manage to live longer than the sober despite the combined lethal effects of cirrhosis, drunk-driving accidents, etc.
Don't get me wrong- heavy drinking isn't good for you. It's just not as bad for you as abstaining completely, which is associated with the highest level of mortality from all causes combined. Moderate drinking is downright healthy, heavy drinking is associated with a lot of problems you'd be wise to avoid- but “puritanism,” when it comes to alcohol, quite literally takes years off your life.
