Effects of acute abstinence and nicotine administration on taste perception in cigarette smokers

Diet quality as assessed by the healthy eating index-2020 among different smoking status: an analysis of national health and nutrition examination survey (NHANES) data from 2005 to 2018

BACKGROUND

Combining smoking with poor eating habits significantly elevates the risk of chronic illnesses and early death. Understanding of how dietary quality shifts post-smoking cessation remains limited. The objective of this study is to examine dietary quality - using Healthy Eating Index (HEI - 2020) and its 13 components, among current, former, and never smokers, and particularly the impact of quitting and the duration of cessation on dietary habits.

METHODS

A cross-sectional analysis of 31,569 adults from the National Health and Nutrition Examination Survey (NHANES) 2005-2018 was conducted. Dietary quality was assessed using HEI-2020 scores, which were determined by NIH developed - simple HEI scoring algorithm per person. Smoking status was categorized into current, former, and never smokers, with further subdivisions for current (heavy/light smokers) and former smokers (duration post-cessation). Descriptive analysis and multiple regression models weighted to represent the US population were performed.

RESULTS

The current smoking rate was 19.4%, with a higher prevalence in males (22.5%) than females (17.5%). Current smokers reported statistically significantly lower HEI total score than both former and never smokers. Former smokers exhibited HEI scores similar to those of never smokers. The adjusted HEI total scores for current, former, and never smokers were 49.2, 54.0, and 53.3, respectively, with a statistically significant difference (p < 0.001). Moreover, light smokers had better total HEI score than heavy smokers (46.8 vs. 50.8, p < 0.001, respectively), but former and never smokers scored even higher. Quitting smoking immediately improved dietary quality, with former smokers reaching the dietary levels of never smokers within 5-10 years (53.8 vs. 53.3, p > 0.05, respectively). Compared to current smokers, former smokers tended to consume more beneficial foods (e.g., fruits, vegetables, greens and beans, whole grains, proteins, and fatty acids), while also consuming more sodium and less added sugar.

CONCLUSIONS

Current smokers, particularly heavy smokers, exhibit poorer dietary habits than former and never smokers. The dietary quality of former smokers aligns with never smokers over time, highlighting the positive impact of smoking cessation on diet. This has implications for reducing chronic disease risks associated with poor diet and smoking.

Does vaping affect the taste and smell perception? An exploratory study with New Zealand young adults

OBJECTIVE

The study aimed to assess potential effects of vaping on individual taste and smell perception in a sample of young adult New Zealanders.

DESIGN

This cross-sectional study measured taste and smell perception using intensity and hedonic ratings to two olfactory (i.e., vanillin, methional) and two gustatory stimuli (i.e., sucrose, monosodium glutamate), representing sweet and savoury flavours. Detection sensitivities to sucrose and vanillin were also assessed using a forced choice detection paradigm aligned with the signal detection framework. MANCOVAs were employed to compare sensory perception between groups based on vaping use frequency. Additional regression analyses were conducted to identify potential predictors of intensity and hedonic sensory ratings.

SETTING

Participants were recruited from the University of Otago student population and surrounding neighbourhoods of Dunedin, New Zealand in 2023.

PARTICIPANTS

The study included 213 university students (98 vapers and 115 non-vapers) RESULTS: We found a significant difference in hedonic ratings for vanillin, indicating a stronger preference among non-vapers. However, no other differences between the two groups were significant. Notably, the use of tobacco and mint flavours were emerged as significant predictors for hedonic responses to the savoury smell and sweet taste stimulus, respectively. No significant differences were observed between groups in the ability to detect weak stimuli.

CONCLUSIONS

Our findings suggest that vape use, particularly with specific flavours, may be associated with alterations in hedonic responses to smells. This finding may have potential implications for how vaping affects on food preferences and dietary choices.

Substitutability of nicotine and sucrose in rats: A behavioral economic analysis

Despite considerable evidence suggesting that sweet foods are a substitute for nicotine in humans, no formal behavioral economic analysis of this interrelationship has been conducted in nonhumans. The purpose of the present study was to examine this phenomenon in rats using concurrent schedules of sucrose pellet, chow pellet, and nicotine reinforcer delivery. Rats responded on separate levers that delivered sucrose pellets, chow pellets, or nicotine infusions under concurrent fixed-ratio (FR) 1 schedules for each commodity within a closed economy. Following stable food and nicotine intake, the unit price of either sucrose or nicotine (the primary commodity) was increased while the two alternative commodities remained unchanged. Substitution was quantified using a behavioral economic cross-price model, as well as a novel commodity relation index that normalizes consumption of dissimilar commodities. Asymmetrical partial substitution was observed, wherein sucrose served as a partial substitute for nicotine, but nicotine failed to substitute for sucrose. Moreover, sucrose was a stronger partial substitute for nicotine than chow in most rats. These findings indicate that substitution of food for nicotine depends on the type of food. These findings mirror the selective increase in carbohydrate intake that can occur during smoking cessation and demonstrate a behavioral economic mechanism that may mediate it.

Inter-individual characteristics on basic taste recognition thresholds in a college-aged cohort: potential predictive factors

Studying nutritional status from the perspective of taste sensitivity, rather than only dietary patterns, may provide new insights into the role of taste receptor signaling in the development of metabolic-associated diseases. In this cross-sectional study, we investigated the possible influence of sociodemographic (sex and smoking habit) and clinical variables (dental cavities, missing teeth, sinusitis, rhinitis, body mass index and metabolic high prevalence family antecedent diseases) on tastant (sucrose, monosodium glutamate, sodium chloride, citric acid, quinine, sinigrin, phenylthiocarbamide) recognition thresholds (RTs) in a college-aged cohort (n = 397). Predictive models for the tastant RTs were generated and a higher sucrose RT was found in females than in males, while sinusitis and rhinitis explained sucrose and sodium chloride RTs. Smoking habit was not an important predictive factor of taste sensitivity, although its long-term influence on RTs remains unclear. Additionally, a positive correlation was found between all the tastant RTs studied. Although results did not show a clear pattern, the statistical approach employed should prove useful in future studies of predictors of taste sensitivity.

Factors Influencing the Phenotypic Characterization of the Oral Marker, PROP

In the last several decades, the genetic ability to taste the bitter compound, 6-n-propyltiouracil (PROP) has attracted considerable attention as a model for understanding individual differences in taste perception, and as an oral marker for food preferences and eating behavior that ultimately impacts nutritional status and health. However, some studies do not support this role. This review describes common factors that can influence the characterization of this phenotype including: (1) changes in taste sensitivity with increasing age; (2) gender differences in taste perception; and (3) effects of smoking and obesity. We suggest that attention to these factors during PROP screening could strengthen the associations between this phenotype and a variety of health outcomes ranging from variation in body composition to oral health and cancer risk.

Tobacco Influence on Taste and Smell: Systematic Review of the Literature

Introduction  In Brazil, estimates show that 14.7% of the adult population smokes, and changes in smell and taste arising from tobacco consumption are largely present in this population, which is an aggravating factor to these dysfunctions.

Objectives  The objective of this study is to systematically review the findings in the literature about the influence of smoking on smell and taste.

Data Synthesis  Our research covered articles published from January 1980 to August 2014 in the following databases: MEDLINE (accessed through PubMed), LILACS, Cochrane Library, and SciELO. We conducted separate lines of research: one concerning smell and the other, taste. We analyzed all the articles that presented randomized controlled studies involving the relation between smoking and smell and taste. Articles that presented unclear methodologies and those whose main results did not target the smell or taste of the subjects were excluded. Titles and abstracts of the articles identified by the research strategy were evaluated by researchers. We included four studies, two of which were exclusively about smell: the first noted the relation between the perception of puff strength and nicotine content; the second did not find any differences in the thresholds and discriminative capacity between smokers and nonsmokers. One article considered only taste and supports the relation between smoking and flavor, another considered both sensory modalities and observes positive results toward the relation immediately after smoking cessation.

Conclusion  Three of the four studies presented positive results for the researched variables.

The effects of nicotine self-administration and withdrawal on concurrently available chow and sucrose intake in adult male rats

Carbohydrate intake, preference, and taste thresholds may be altered in current and former cigarette smokers, which may mediate weight gain and risk for obesity in individuals who quit smoking. Attempts to model these effects in rodents have primarily used noncontingent nicotine administration. The purpose of this research was to characterize changes in chow and sucrose intake in rats during a 23-h access model of i.v. nicotine self-administration (NSA), in which rats lever-pressed for chow, sucrose, and nicotine under concurrent fixed-ratio (FR) 1 schedules. Male rats were assigned to one of three groups that differed in food and drug availability. The Nicotine C+S group had concurrent access to nicotine, chow, and sucrose. The Saline C+S group had access to saline, chow, and sucrose. The Nicotine C-Only group had access to nicotine and chow, but not sucrose. Changes in food intake and weight gain were assessed during baseline, NSA, and nicotine withdrawal (i.e., saline extinction). Weight gain was significantly slowed during NSA and increased during withdrawal, but did not differ between the nicotine groups. NSA produced a significant decrease in both chow and sucrose intake. Gradual tolerance to nicotine's effects on sucrose, but not chow intake, occurred. During withdrawal, chow and sucrose intake increased, with a larger percent increase in sucrose intake compared to chow. The proportion of total food intake from sucrose was greater at the end of withdrawal compared to baseline, indicating a history of nicotine intake changed dietary preference. Combined, these results indicate that sucrose intake is more resistant to nicotine's appetite suppressant effects and withdrawal from nicotine produces a greater increase in sweet food intake alongside general increases in chow intake. Changes in overall food intake in current and ex-smokers may lead to increased risk for obesity and other health problems, potentially limiting the benefit of quitting smoking.

Relationships of PROP Taste Phenotype, Taste Receptor Genotype, and Oral Nicotine Replacement Use

INTRODUCTION

Recommended dosage of oral nicotine replacement therapy (NRT) product is often not achieved in smoking cessation attempts. n-6-propylthiouracil (PROP) bitter taste phenotype may be a potential risk factor for non-adherence to oral NRT products due to their bitter taste. There is limited literature on this phenotype in the context of smoking and none in relation to oral NRT pharmacotherapy.

METHODS

The association of PROP taste phenotype with NRT usage and sensory response to products was examined. In a cross-over experimental design, 120 participants received a 1 week supply of nicotine inhalers and 1 week of nicotine lozenges with random assignment to order. Mixed effects linear model analyses were conducted.

RESULTS

PROP taste phenotype and taste receptor genotype were not associated with NRT usage or sensory response to NRT, after adjusting for other factors. However, PROP non-tasters used a higher number of lozenges per day (continuous exposure) than nicotine cartridges (intermittent exposure). Unexpectedly, half of baseline PROP non-tasters shifted to taster phenotype 2 weeks after smoking cessation or reduction. Menthol cigarette smokers identified higher NRT strength of sensation scores than nonmenthol smokers. Taste receptor genotype was related to PROP taste phenotype (Kendall τ = .591, p = .0001).

CONCLUSIONS

A nonsignificant relationship of PROP phenotype and NRT usage may be associated with NRT under-dosing and limited variance in the outcome variable. PROP non-tasters' greater use of lozenges is consistent with nicotine exposure being less aversive to non-tasters. Further research of this and other factors impacting NRT usage are warranted to effectively inform smoking cessation pharmacotherapy.

Impaired taste and increased mortality in acutely hospitalized older people

Taste ability is known to be impaired in elderly and even more so in acutely hospitalized elderly people. To our knowledge, no study has investigated the association between taste impairment and mortality. Our aim was to examine this association in acutely hospitalized older people. In a prospective study, 200 acutely hospitalized elderly people ≥70 years of age were included between November 2009 and October 2010 at the Oslo University Hospital, Norway. Exclusion criteria were cognitive impairment, nursing home residency, and terminal diseases. Comorbidity was registered with the Cumulative Illness Rating Scale, in addition to recording of age, gender, smoking, education, and number of medications. Taste ability was assessed quantitatively with the "taste strips method" in 174 patients (mean age: 84 years). Mortality until 1 January 2012 was obtained from hospital records. Fifty-six patients died during the observation period. The relative risk of death in total taste score quartile 4 compared with total taste score quartile 1 was 0.31 (95% confidence interval [95% CI]: 0.14-0.69, P = 0.004), after adjusting for age, gender, smoking, education, and Cumulative Illness Rating Scale. Adjusted 1-year mortality decreased from 30% in total taste score quartile 1 to 9% in total taste score quartile 4. Thus, impaired taste appears to be strongly associated with mortality in acutely hospitalized elderly people.

Single bright light exposure decreases sweet taste threshold in healthy volunteers

INTRODUCTION

Bright light exposure can alter circulating serotonin levels, and alteration of available serotonin by acute selective serotonin reuptake inhibition significantly lowers sweet but not salt taste recognition thresholds. We tested the hypothesis that bright light exposure would increase sweet but not salt taste sensitivity in healthy adults.

METHODS

Fourteen healthy volunteers were exposed to bright (10,000 lux) and dim (<20 lux) light for 30 min each, in counterbalanced order. Measures of taste perception (salt and sweet) and mood were determined at baseline, and before and after each light exposure period.

RESULTS

Recognition thresholds for sucrose were significantly lower after bright but not dim light exposure. Thresholds for salt were unaffected by either condition. There were no significant changes in taste acuity, intensity or pleasantness for both the taste modalities and on visual analogue scales (VASs) for mood, anxiety, sleepiness and alertness, under either light condition.

CONCLUSION

Brief bright light exposure reduces sweet but not salt taste recognition thresholds in healthy humans.

Opiate agonists and antagonists modulate taste perception in opiate-maintained and recently detoxified subjects

Heroin addicts consume large quantities of refined sugars. This study investigated the effect of opiate use and antagonism on sweet taste in opiate-maintained drug users and detoxified former chronic opiate users, using a within-subject design. Seven opiate users received methadone and seven buprenorphine maintenance. Six detoxified subjects received naltrexone. Sucrose recognition thresholds and measurements of pleasantness and intensity were determined before and four hours after 1) a single dose of methadone or buprenorphine or 2) naltrexone. Control data were taken from a cohort of healthy volunteers including smokers. All measures of sweet and salt taste perception were significantly greater in opiate users and recently detoxified subjects compared to control subjects, with the exception of sweet pleasantness, which returned to control level after detoxification. Acute methadone administration reduced salt thresholds and unpleasantness to control levels. Increased sweet thresholds and salt unpleasantness in detoxified subjects were reversed by acute opioid antagonism, returning to control levels. These results suggest that opiate use and antagonism alters taste perception. Some of the alterations reverse on detoxification (sweet pleasantness), and others can be reversed by opioid antagonism (sweet threshold, salt unpleasantness). Changes in taste perception may underlie altered consumption of refined sugars in opiate users.

Scientific assessment of the use of sugars as cigarette tobacco ingredients: a review of published and other publicly available studies

Sugars, such as sucrose or invert sugar, have been used as tobacco ingredients in American-blend cigarettes to replenish the sugars lost during curing of the Burley component of the blended tobacco in order to maintain a balanced flavor. Chemical-analytical studies of the mainstream smoke of research cigarettes with various sugar application levels revealed that most of the smoke constituents determined did not show any sugar-related changes in yields (per mg nicotine), while ten constituents were found to either increase (formaldehyde, acrolein, 2-butanone, isoprene, benzene, toluene, benzo[k]fluoranthene) or decrease (4-aminobiphenyl, N-nitrosodimethylamine, N-nitrosonornicotine) in a statistically significant manner with increasing sugar application levels. Such constituent yields were modeled into constituent uptake distributions using simulations of nicotine uptake distributions generated on the basis of published nicotine biomonitoring data, which were multiplied by the constituent/nicotine ratios determined in the current analysis. These simulations revealed extensive overlaps for the constituent uptake distributions with and without sugar application. Moreover, the differences in smoke composition did not lead to relevant changes in the activity in in vitro or in vivo assays. The potential impact of using sugars as tobacco ingredients was further assessed in an indirect manner by comparing published data from markets with predominantly American-blend or Virginia-type (no added sugars) cigarettes. No relevant difference was found between these markets for smoking prevalence, intensity, some markers of dependence, nicotine uptake, or mortality from smoking-related lung cancer and chronic obstructive pulmonary disease. In conclusion, thorough examination of the data available suggests that the use of sugars as ingredients in cigarette tobacco does not increase the inherent risk and harm of cigarette smoking.