[letharion]

Also it has been pointed out elsewhere, that previous alcoholics will likely show up as non-drinkers in a study like this, but will already have done significant damage to their health. The result being that not drinking looks worse than it is.

[nraynaud]

I would add that even if they recovered, drinkers increase their risk for a few cancer, so you probably can't just assess their past health issues to correct the life expectancy.