Chewing Gum

There has been recent interest in the ergogenic effects of caffeine delivered in low doses (~ 200 mg or ~ 3 mg/kg body mass) and administered in forms other than capsules, coffee and sports drinks, including chewing gum, bars, gels, mouth rinses, energy drinks and aerosols. Caffeinated chewing gum is absorbed quicker through the buccal mucosa compared with capsule delivery and absorption in the gut, although total caffeine absorption over time is not different. Rapid absorption may be important in many sporting situations. Caffeinated chewing gum improved endurance cycling performance, and there is limited evidence that repeated sprint cycling and power production may also be improved. Mouth rinsing with caffeine may stimulate nerves with direct links to the brain, in addition to caffeine absorption in the mouth. However, caffeine mouth rinsing has not been shown to have significant effects on cognitive performance. Delivering caffeine with mouth rinsing improved short-duration, high-intensity, repeated sprinting in normal and depleted glycogen states, while the majority of the literature indicates no ergogenic effect on aerobic exercise performance, and resistance exercise has not been adequately studied. Studies with caffeinated energy drinks have generally not examined the individual effects of caffeine on performance, making conclusions about this form of caffeine delivery impossible. Caffeinated aerosol mouth and nasal sprays may stimulate nerves with direct brain connections and enter the blood via mucosal and pulmonary absorption, although little support exists for caffeine delivered in this manner. Overall, more research is needed examining alternate forms of caffeine delivery including direct measures of brain activation and entry of caffeine into the blood, as well as more studies examining trained athletes and female subjects.

RationaleElectronic cigarettes (ECs) are becoming popular alternatives for smokers, but there has been limited study of their abuse liability.ObjectivesThe objective of this study was to evaluate the abuse liability of three Vuse Solo ECs, ranging from 14 to 36 mg in nicotine content, relative to high- and low-abuse liability comparator products (usual brand combustible cigarettes and nicotine gum, respectively) in a group of 45 EC-naïve smokers.MethodsEnrolled subjects' ratings of subjective effects and nicotine uptake over 6 h were used to measure abuse liability and pharmacokinetics following in-clinic use of each EC.ResultsUse of Vuse Solo resulted in subjective measures and nicotine uptake that were between those of combustible cigarettes and nicotine gum, although generally closer to nicotine gum. Compared to combustible cigarettes, use of Vuse Solo resulted in significantly lower scores in measures of product liking, positive effects, and intent to use again. These pharmacodynamic findings were consistent with the pharmacokinetic data, showing that cigarettes produced substantially faster and higher levels of nicotine uptake as compared to Vuse Solo and nicotine gum. Vuse Solo resulted in more rapid initial uptake of nicotine compared to nicotine gum, but peak concentration and long-term extent of uptake were not different or were lower with Vuse.ConclusionsCollectively, these findings suggest that Vuse Solo likely has an abuse liability that is somewhat greater than nicotine gum but lower than cigarettes.Trial registrationClinicalTrials.gov identifier: NCT02269514.

IntroductionThe aerosol composition of electronic cigarettes (ECs) suggests that exposure to toxicants during use is greatly reduced compared to exposure from combustible cigarettes (CCs).MethodsThis randomized, parallel-group, clinical study enrolled smokers to switch to Vuse Solo (VS) Digital Vapor Cigarettes (Original or Menthol) or Nicorette 4 mg nicotine gum (NG) in a controlled setting. Subjects who smoked CCs ad libitum for 2 days during a baseline period were then randomized to ad libitum use of either VS or NG for 5 days. Biomarkers of 23 toxicants were measured in 24-hour urine samples and blood collected at baseline and following product switch.ResultsA total of 153 subjects completed the study. Total nicotine equivalents decreased in all groups, but higher levels were observed in the VS groups compared to the NG groups, with decreases of 38% and 60%-67%, respectively. All other biomarkers were significantly decreased in subjects switched to VS, and the magnitude of biomarker decreases was similar to subjects switched to NG. Decreases ranged from 30% to greater than 85% for constituents such as benzene and acrylonitrile.ConclusionsThese results indicate that exposure to toxicants when using VS is significantly reduced compared to CC smoking, and these reductions are similar to those observed with use of NG. Although statistically significantly decreased, nicotine exposure is maintained closer to CC smoking with VS use compared to NG use. This research suggests that use of VS exposes consumers to fewer and lower levels of smoke toxicants than CCs while still providing nicotine to the consumer.ImplicationsThis is the first study to report changes in nicotine delivery and biomarkers of tobacco exposure following a short-term product switch from CCs to either an EC or NG in a controlled environment. The study shows that nicotine exposure decreased in both groups but was maintained closer to CC smoking with the EC groups. Biomarkers of tobacco combustion decreased to similar levels in both EC and gum groups.

PurposeThis study examined whether 3 mg·kg-1 (CAF3) and 6 mg·kg-1 (CAF6) caffeine gum, administered before a standardized resistance-priming (RP) protocol, produced additional neuromuscular performance advantages over placebo (PLA) at 1 h, 24 h, and 48 h in male basketball players.MethodsFifteen male basketball players completed three randomized, double-blind, placebo-controlled crossover conditions: PLA+RP, CAF3+RP, and CAF6+RP. After 15 min of gum chewing, participants performed a standardized warm-up followed by RP consisting of 3 × 3 back squats at 85% 1RM. Mean concentric velocity (MV) was recorded during RP. Performance tests were conducted at 1 h, 24 h, and 48 h post-RP and included isometric mid-thigh pull peak force and 200-ms rate of force development, countermovement jump height, 20-m sprint, Y-shaped reactive agility, and Lane Agility Test. Data were analyzed using linear mixed-effects models adjusted for experimental period and administration sequence.ResultsSignificant dose × time interactions were observed for all performance outcomes except the Lane Agility Test. At 1 h, CAF3+RP and CAF6+RP produced superior performance compared with PLA+RP in isometric strength, explosive power, sprint, and reactive agility outcomes. No significant differences were observed between CAF3 and CAF6. At 24 h and 48 h, no additional between-condition advantages were found for either caffeine dose compared with PLA. Barbell MV during RP was higher under caffeine conditions than PLA, indicating greater RP training output.ConclusionWithin a standardized RP context, CAF3 and CAF6 caffeine gum were associated with improved same-day neuromuscular performance and higher RP barbell velocity compared with PLA, but no additional between-condition advantages were observed at 24 h or 48 h. Because this study did not include pre-intervention baseline testing, a caffeine-only condition, or a no-RP control condition, the findings should be interpreted as caffeine-related differences within an RP context rather than direct evidence of the independent effects of caffeine, RP, or their interaction.