Effects of sweet flavorings and nicotine on the appeal and sensory properties of e-cigarettes among young adult vapers: Application of a novel methodology

Abstract

Introduction: Product characteristics that impact e-cigarette appeal by altering the sensory experience of vaping need to be identified to formulate evidence-based regulatory policies. While products that contain sweet flavorings and produce a "throat hit" (i.e., desirable airway irritation putatively caused by nicotine) are anecdotally cited as desirable reasons for vaping among young adults, experimental evidence of their impact on user appeal is lacking. This experiment applied a novel laboratory protocol to assess whether: (1) sweet flavorings and nicotine affect e-cigarette appeal; (2) sweet flavorings increase perceived sweetness; (3) nicotine increases throat hit; and (4) perceived sweetness and throat hit are associated with appeal.

Methods: Young adult vapers (N=20; age 19-34) self-administered 20 standardized doses of aerosolized e-cigarette solutions varied according to a 3 flavor (sweet [e.g., cotton candy] vs. non-sweet [e.g., tobacco-flavored] vs. flavorless)×2 nicotine (6mg/mL nicotine vs. 0mg/mL [placebo]) double-blind, cross-over design. Participants rated appeal (liking, willingness to use again and perceived monetary value), perceived sweetness and throat hit strength after each administration.

Results: Sweet-flavored (vs. non-sweet and flavorless) solutions produced greater appeal and perceived sweetness ratings. Nicotine produced greater throat hit ratings than placebo, but did not significantly increase appeal nor interact with flavor effects on appeal. Controlling for flavor and nicotine, perceived sweetness was positively associated with appeal ratings; throat hit was not positively associated with appeal.

Conclusions: Further identification of compounds in e-cigarette solutions that enhance sensory perceptions of sweetness, appeal, and utilization of e-cigarettes are warranted to inform evidence-based regulatory policies.

Keywords: Appeal; Flavoring; Nicotine; Tobacco regulatory science; e-Cigarette.

Figure 1

Appeal, Sweetness and Throat Hit Ratings by Flavor Type and Nicotine (Mean±SE). ^†Significantly greater than “Not Sweet” in pairwise contrast (p<0.0001). ^*Significantly greater than “ lavorless” in pairwise contrast (p<0.0001). ◆Significantly greater than “Placebo” in pairwise contrast (p<0.0001). Like = “How much did you like it?”; Use Again = “Would you use the it again?”; Pay = “How much would you pay for a day’s worth of it?”; Sweetness = “How sweet was it?”; hroat Hit = “How strong was the throat hit?”

Figure 2

Scatter Plots with Linear Trend Line of Appeal Ratings by Sweetness and Throat Hit Rating. B’s and p-values were obtained from multilevel linear models that treated sweetness and throat hit rating as a time-varying regressor variable. All ratings besides “Pay” were made on Visual Analog Scales (0–100). Like = “How much did you like it?”; Use Again = “Would you use the it again?”; Pay = “How much would you pay for a day’s worth of it?”; Sweetness = “How sweet was it?”; hroat Hit = “How strong was the throat hit?”.

Figure 2

Scatter Plots with Linear Trend Line of Appeal Ratings by Sweetness and Throat Hit Rating. B’s and p-values were obtained from multilevel linear models that treated sweetness and throat hit rating as a time-varying regressor variable. All ratings besides “Pay” were made on Visual Analog Scales (0–100). Like = “How much did you like it?”; Use Again = “Would you use the it again?”; Pay = “How much would you pay for a day’s worth of it?”; Sweetness = “How sweet was it?”; hroat Hit = “How strong was the throat hit?”.