The impact of snus and ethanol on cigarette craving and consumption

Abstract

This dissertation examines the extent to which Swedish snus, a moist oral tobacco product, impacts the effect of alcohol consumption on cigarette smoking and craving. Alcohol-induced cigarette craving has been noted through anecdotal self-report by smokers who drink and also robustly demonstrated in lab-based studies, yet the mechanism by which this occurs is unknown and contested in the literature. Experimental confounds need to be controlled as thoroughly as possible to study the alcohol-tobacco co-use phenomenon. Swedish snus allows experimenters to administer a tobacco product to North American participants without activating the expectancies associated with other smoking devices or tobacco products. As well, snus is pasteurized instead of burnt, meaning that any effects snus has on alcohol-induced cigarette craving and consumption can be attributed to those tobacco factors, including nicotine, found within tobacco, and not the additional compounds present within cigarette smoke. Three lab-based studies were conducted utilizing double-blind procedures. In the first two of them, only dependent smokers who drank alcohol were recruited. In the third, both dependent and non-dependent smokers who also drank were recruited. The studies examined the effect snus had on cigarette administration and craving when preceded by alcohol administration (Studies 1 and 3) or followed by it (Study 2). In Study 1, snus reduced the number of cigarette puffs and how hard dependent smokers worked for additional puffs when snus was administered before a one-hour progressive ratio (PR) task (Barrett, 2010); this was true regardless of alcohol consumption. Neither alcohol nor snus influenced cigarette craving before the PR task. In Study 2, snus administration preceded alcohol administration, followed by the PR task. Snus increased the latency to start smoking, whereas alcohol increased efforts to earn puffs. Study 3 was designed similarly to Study 1, with a more extended tobacco abstinence period and a smaller dose of snus, but with both dependent and non-dependent smokers. In Study 3 snus reduced dependent smokers’ puffs and how hard they worked to earn additional puffs similar to Study 1, but snus did not affect non-dependent smokers’ cigarette craving or smoking behavior. Alcohol increased cigarette craving and latency to start smoking only with non- dependent smokers. The results of these studies show that snus reduces cigarette consumption regardless of alcohol or placebo beverage consumption in tobacco-dependent smokers. The findings also suggest that chemicals found in non-pyrolyzed tobacco, including nicotine, can satiate tobacco consumption in dependent smokers. This relationship appears to be different for non-dependent smokers who may be motivated to consume tobacco for different pharmacological or psychological reasons including different cigarette specific expectations, or non-pharmacological sensory-motor properties of smoking.