What's new in mouth rinse nutrition? Update on fluid and menthol

This session will provide an update on the perceptual, physiological and performance effects of menthol mouth swilling during exercise performance, and the associated mechanisms underpinning these changes. Cooling stimuli applied to the oral cavity impart feelings of freshness that are familiar to users of oral hygiene and other menthol containing products, such as confectionary or oral analgesics, this sensation can be imparted by either physiological or perceptual cooling. Cold fluids provide a cooling sensation by stimulating oral cold receptors, and can attenuate thirst through post-absorptive mechanisms; menthol mimics the provision of oral cooling stimuli, by acting as a cold-receptor agonist to TRPM8 channels, and trigeminal and cold-sensitive neurons in the face and oral cavity. This invokes perceived thermal changes in congruence with an environmental temperature range of 8-28°c, the magnitude of which is inversely proportional to the thickness of the stratum corneum in the region that menthol is applied. Hence, the oral application of menthol and cold fluids may lower individuals’ thermal sensation, improve thermal comfort and attenuate thirst, independent of physiological changes in temperature. This attenuation of thermal symptoms may be perceived as hedonic, and concomitantly improve exercise performance. To date literature has focused on endurance exercise performance in hot environmental conditions, with menthol mouth swilling improving time to exhaustion performance in cyclists, and time trial performance in runners and triathletes. Menthol may also provide an additive perceptual cooling stimulus when applied alongside physiological cooling strategies, in a temperature dependent manner. There are limited data pertaining to menthol mouth swilling and power related activities at present. The timing of menthol throughout the exercise bout may affect its ergogenic properties, but this research is also in its preliminary stages. Future research should aim to individualise menthol mouth swilling based upon personal preference and sensitivity; further personalisation of swilling strategies may be achieved by investigating the timing of swilling during the exercise bout and utilising menthol in conjunction with other ergogenic nutritional strategies. The possibility of habituation to menthol mouth swilling also warrants investigation

Menthol sensory qualities and smoking topography: a review of tobacco industry documents.

ObjectiveTo determine what the tobacco industry knew about the potential effects of menthol on smoking topography-how a person smokes a cigarette.MethodsA snowball strategy was used to systematically search the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu) between 1 June 2010 and 9 August 2010. We qualitatively analysed a final collection of 252 documents related to menthol and smoking topography.ResultsThe tobacco industry knew that menthol has cooling, anaesthetic and analgesic properties that moderate the harshness and irritation of tobacco. Owing to its physiological effects, menthol contributes to the sensory qualities of the smoke and affects smoking topography and cigarette preference.ConclusionOur review of industry studies suggests that the amount of menthol in a cigarette is associated with how the cigarette is smoked and how satisfying it is to the smoker. If menthol in cigarettes was banned, as the US Food and Drug Administration (FDA) is currently considering, new/experimental smokers might choose not to smoke rather than experience the harshness of tobacco smoke and the irritating qualities of nicotine. Similarly, established menthol smokers might choose to quit if faced with an unpleasant smoking alternative

Menthol mouth rinsing: An applied perspective

With the Tokyo Olympics rapidly approaching, and increasing global temperatures, applied nutrition practitioners and supporting scientists are looking for ways to physiologically cool their athletes, but the value of perceptual cooling is also gaining a profile; menthol mouth swilling is one such strategy. This article provides a brief synopsis of menthol research to date, followed by a reflection of how we have used menthol mouth rinsing to complement anIro nman™ triathlete’s event nutrition strategy, and concludes by highlighting ethical concerns with menthol mouth rinsing

Topical Menthol, Ice, Peripheral Blood Flow, and Perceived Discomfort

Context : Injury management commonly includes decreasing arterial blood flow to the affected site in an attempt to reduce microvascular blood flow and edema and limit the induction of inflammation. Applied separately, ice and menthol gel decrease arterial blood flow, but the combined effects of ice and menthol gel on arterial blood flow are unknown. Objectives : To compare radial artery blood flow, arterial diameter, and perceived discomfort before and after the application of 1 of 4 treatment conditions. Design : Experimental crossover design. Setting : Clinical laboratory. Participants or Other Participants : Ten healthy men, 9 healthy women (mean age = 25.68 years, mean height = 1.73 m, mean weight = 76.73 kg). Intervention(s) : Four treatment conditions were randomly applied for 20 minutes to the right forearm of participants on 4 different days separated by at least 24 hours: (1) 3.5 mL menthol gel, (2) 0.5 kg of crushed ice, (3) 3.5 mL of menthol gel and 0.5 kg of crushed ice, or (4) no treatment (control). Main Outcome Measure(s) : Using high-resolution ultrasound, we measured right radial artery diameter (cm) and blood flow (mL/min) every 5 minutes for 20 minutes after the treatment was applied. Discomfort with the treatment was documented using a 1-to-10 intensity scale. Results : Radial artery blood flow decreased (P \u3c .05) from baseline in the ice (−20% to −24%), menthol (−17% to −24%), and ice and menthol (−36% to −39%) treatments but not in the control (3% to 9%) at 5, 10, and 15 minutes. At 20 minutes after baseline, only the ice (−27%) and combined ice and menthol (−38%) treatments exhibited reductions in blood flow (P \u3c .05). Discomfort was less with menthol than with the ice treatment at 5, 10, and 20 minutes after application (P \u3c .05). Arterial diameter and heart rate did not change. Conclusions : The application of 3.5 mL of menthol was similar to the application of 0.5 kg of crushed ice in reducing peripheral blood flood. Combining crushed ice with menthol appeared to have an additive effect on reducing blood flow

The effectiveness of orally applied L-menthol on exercise performance in the heat

During exercise in the heat, increasing thermal load leads to thermo-behavioural adjustments in exercise performance, due to greater perceptual and physiological strain. Behavioural reductions in exercise intensity in the heat are initially mediated via rises in skin temperature, which alter thermal perception (comfort and sensation) and later by rises in core temperature, which increase cardiovascular strain and perceived exertion. Therefore, thermoregulation may be ordered and dependant on the magnitude, timing and/or prioritisation of afferent signals. Non-thermal cooling via L-menthol has been shown to enhance exercise performance in the early and latter stages when delivered orally at a concentration of 0.01%. Indeed, during periods of progressive thermal stress, imposed by the combination of maximal exercise and environmental heat and humidity, L-menthol has been shown to offer an immediate cooling stimulus thus extending exercise capacity. However, repeated administration of L-menthol during exercise in the heat, as thermal load increases, is unable to recover a decline in work rate. Therefore, it is unclear whether the potency of L-menthol is sustained upon frequent application and what strategies are needed in both sporting and occupational settings to optimise its effectiveness. In this part of the symposium we will consider oral delivery of L-menthol and its potential for reducing an individual’s perception of heat stress with associated effects on exercise tolerance in the heat. We will also examine the frequency of use, optimal concentration, timing and novelty of L-menthol in a sporting and occupational context

In Vitro Consequences of Electronic-Cigarette Flavoring Exposure on the Immature Lung.

Background: The developing lung is uniquely susceptible and may be at increased risk of injury with exposure to e-cigarette constituents. We hypothesize that cellular toxicity and airway and vascular responses with exposure to flavored refill solutions may be altered in the immature lung. Methods: Fetal, neonatal, and adult ovine pulmonary artery smooth muscle cells (PASMC) were exposed to popular flavored nicotine-free e-cigarette refill solutions (menthol, strawberry, tobacco, and vanilla) and unflavored solvents: propylene glycol (PG) or vegetable glycerin (VG). Viability was assessed by lactate dehydrogenase assay. Brochodilation and vasoreactivity were determined on isolated ovine bronchial rings (BR) and pulmonary arteries (PA). Results: Neither PG or VG impacted viability of immature or adult cells; however, exposure to menthol and strawberry flavored solutions increased cell death. Neonatal cells were uniquely susceptible to menthol flavoring-induced toxicity, and all four flavorings demonstrated lower lethal doses (LD50) in immature PASMC. Exposure to flavored solutions induced bronchodilation of neonatal BR, while only menthol induced airway relaxation in adults. In contrast, PG/VG and flavored solutions did not impact vasoreactivity with the exception of menthol-induced relaxation of adult PAs. Conclusion: The immature lung is uniquely susceptible to cellular toxicity and altered airway responses with exposure to common flavored e-cigarette solutions

Oral application of L-menthol in the heat: From pleasure to performance

When menthol is applied to the oral cavity it presents with a familiar refreshing sensation and cooling mint flavour. This may be deemed hedonic in some individuals, but may cause irritation in others. This variation in response is likely dependent upon trigeminal sensitivity toward cold stimuli, suggesting a need for a menthol solution that can be easily personalised. Menthol’s characteristics can also be enhanced by matching colour to qualitative outcomes; a factor which can easily be manipulated by practitioners working in athletic or occupational settings to potentially enhance intervention efficacy. This presentation will outline the efficacy of oral menthol application for improving time trial performance to date, either via swilling or via co-ingestion with other cooling strategies, with an emphasis upon how menthol can be applied in ecologically valid scenarios. Situations in which performance is not expected to be enhanced will also be discussed. An updated model by which menthol may prove hedonic, satiate thirst and affect ventilation will also be presented, with the potential performance implications of these findings discussed and modelled. Qualitative reflections from athletes that have implemented menthol mouth swilling in competition, training and maximal exercise will also be included

Effects of Very Low Nicotine Content Cigarettes on Smoking Behavior and Biomarkers of Exposure in Menthol and Non-menthol Smokers.

IntroductionBecause 30% of cigarettes sold in the United States are characterized as menthol cigarettes, it is important to understand how menthol preference may affect the impact of a nicotine reduction policy.MethodsIn a recent trial, non-treatment-seeking smokers were randomly assigned to receive very low nicotine cigarettes (VLNC; 0.4 mg nicotine/g tobacco) or normal nicotine cigarettes (NNC; 15.5 mg/g) for 20 weeks. On the basis of preference, participants received menthol or non-menthol cigarettes. We conducted multivariable regression analyses to examine whether menthol preference moderated the effects of nicotine content on cigarettes per day (CPD), breath carbon monoxide (CO), urinary total nicotine equivalents (TNE), urinary 2-cyanoethylmercapturic acid (CEMA), and abstinence.ResultsAt baseline, menthol smokers (n = 346) reported smoking fewer CPD (14.9 vs. 19.2) and had lower TNE (52.8 vs. 71.6 nmol/mg) and CO (17.7 vs. 20.5 ppm) levels than non-menthol smokers (n = 406; ps < .05). At week 20, significant interactions indicated that menthol smokers had smaller treatment effects than non-menthol smokers for CPD (-6.4 vs. -9.3), TNE (ratio of geometric means, 0.22 vs. 0.10) and CEMA (ratio, 0.56 vs. 0.37; ps < .05), and trended toward a smaller treatment effect for CO (-4.5 vs. -7.3 ppm; p = .06). Odds ratios for abstinence at week 20 were 1.88 (95% confidence interval [CI] = 0.8 to 4.4) for menthol and 9.11 (95% CI = 3.3 to 25.2) for non-menthol VLNC smokers (p = .02) relative to the NNC condition.ConclusionsAlthough menthol smokers experienced reductions in smoking, toxicant exposure, and increases in quitting when using VLNC cigarettes, the magnitude of change was smaller than that observed for non-menthol smokers.ImplicationsResults of this analysis suggest that smokers of menthol cigarettes may respond to a nicotine reduction policy with smaller reductions in smoking rates and toxicant exposure than would smokers of non-menthol cigarettes

Comparing The Effects Of Menthol Status On The Behavioral Pharmacology Of Smoking Reduced Nicotine Content Cigarettes

Introduction: An active area of tobacco regulatory science research focuses on examining the effects of varying the nicotine content of cigarettes as part of a potential national policy to lower their nicotine content levels to reduce addiction potential. The present study examines differences in the behavioral effects of reduced nicotine content cigarettes related to their menthol status. Menthol is the only cigarette flavoring that is still legally permissible according to Food and Drug administration regulations. Methods: Participants were 26 current adult smokers from three populations especially vulnerable to tobacco use and addiction (economically disadvantaged women, opioid-dependent individuals, individuals with affective disorders) dichotomized as menthol (n=11) or non-menthol (n=15) smokers. Participants completed 14 experimental sessions following acute smoking abstinence (CO\u3c50% baseline level). Across sessions, participants smoked four Spectrum research cigarettes (22nd Century Group, Clarence, NY) with varying nicotine content levels (0.4mg/g, 2.4 mg/g, 5.2 mg/g, 15.8 mg/g) or their usual brand cigarette. Research cigarettes were mentholated or non-mentholated corresponding to participants usual brand. Upon completion of smoking, participants completed tasks measuring reinforcing efficacy, subjective effects, topography, and withdrawal and craving measures. Repeated Measures Analysis of Variance was used for all analyses (p\u3c.05). Results: Main effects of menthol status, as well as interactions of nicotine dose and menthol were noted across subscales of subjective effects and direct assessments of reinforcing efficacy. Usual brand mentholated cigarettes produced a profile of equal or greater relative reinforcing effects than usual brand non-mentholated cigarettes, while mentholated research cigarettes produced a profile of effects that fell below (i.e., lower relative reinforcing effects compared to usual brand or non-mentholated cigarettes) those of non-mentholated research cigarettes. Conclusions: Mentholated research cigarettes produce a lower profile of reinforcing and subjective effects, without discernible differences in smoking topography. The potential impact of mentholation on reinforcing efficacy and subjective effects should be considered when using Spectrum research cigarettes