First up, the J-Curve. With a tip of the titfer to Eric Crampton, I give you these graphs (click to enlarge)...
What do these graphs show? Firstly, they show that the safe drinking guidelines issued by the UK's medical establishment—21 units a week for women and 28 units for men—are arbitrary an scientifically insupportable, but you knew that already.
Secondly, that drinking moderately is good for you and that the reduced risk of mortality seen in drinkers is not due to the 'sick quitter hypothesis'—note that the first graph shows that the benefits of drinking are not as strong when former drinkers are included in the analysis, but they are still substantial.
Thirdly, that the optimal level of drinking is quite low, at around one drink per day (or 5-10 units per week), but that you would have to drink a lot more than before your mortality risk rises to that of a teetotaller. If complete abstinence is 'safe', then so is drinking 30, 40 and perhaps 50 units a week. Only beyond this point does one's risk rise above that of the teetotaller.
The epidemiological evidence for this is robust and has defied alternative explanations. Nevertheless, the public health racket is determined to reduce the guidelines still further. It's not about science, it's about propaganda. The scale of a country's supposed booze epidemic is now largely measured by how many people exceed these risible guidelines. Surprisingly few do, even when weekly guidelines are (illegitimately) reduced to daily guidelines, and overall consumption has been falling for a decade, so lowering the limit is the puritans' best chance of sustaining the moral panic.
Stephen Fry has more...
And, from James Nicholls' splendid book The Politics of Alcohol, here's what the drinking guidelines were in 1979...
And here's why they were changed...
