Coffee and alcohol intake as predictors of smoking cessation and tobacco withdrawal.

In one study of 105 smokers who received physician advice plus placebo gum and in another study of 630 self-quitters, neither the presence or absence, nor amount of precessation alcohol, nor coffee intake, nor changes in alcohol or coffee intake postcessation, predicted relapse or most withdrawal symptoms. The one possible exception was that heavy caffeine and alcohol users reported a greater increase in hunger and craving postcessation; however, these effects were not consistent across measures, follow-ups, and studies. Our results are inconsistent with theories that caffeine intoxication from increased caffeine blood levels postsmoking cessation worsen tobacco withdrawal or that alcohol or caffeine use during initial abstinence from smoking increases relapse to smoking.