Context matters: Neural processing of food-flavored e-cigarettes and the influence of smoking

E -cigarettes are harmful, addictive, and popular. In e -cigarettes, nicotine is often paired with food -flavors. How this pairing of nicotine and food cues influences neural processing warrants investigation, as in smokers, both types of cues activate similar brain regions. Additionally, while most e -cigarettes are sweet, savory e -cigarettes are seemingly absent, although savory flavors are commonly liked in food. To understand how smoking status and type of flavor modulate reactions to food -flavored e -cigarettes, in comparison to actual food, neural and subjective responses to food odors were measured in a 2 (sweet vs. savory odor) x2 (food vs. e -cigarette context) x2 (smokers vs. non-smokers) design in 22 occasional/light smokers and 25 non-smokers. During fMRI scanning, participants were exposed to sweet and savory odors and pictures creating the two contexts. Liking and wanting were repeatedly measured on a 100 -unit visual -analogue -scale. Results show that sweet e -cigarettes were liked (Delta = 14.2 +/- 1.7) and wanted (Delta = 39.5 +/- 3.1) more than savory e -cigarettes, and their cues activated the anterior cingulate more (cluster -level qFDR = 0.003). Further, we observed context -dependent variations in insula response to odors (cluster -level qFDR = 0.023, and = 0.030). Savory odors in an e -cigarette context were wanted less than the same odors in a food -context (Delta = 32.8 +/- 3.1). Smokers and non-smokers reacted similarly to flavored product cues. Our results indicate that the principles of flavor preference in food cannot directly be applied to e -cigarettes and that it is challenging to design sweet and savory e -cigarettes to appeal to smokers only.