Effects of club soda and ginger brew on linguapalatal pressures in healthy swallowing

The Effect of Genetic Taste Status on Swallowing: A Literature Review

PURPOSE

Swallowing and taste share innervation pathways and are crucial to nutritive intake. Individuals vary in their perception of taste due to factors such as genetics; however, it is unclear to what extent genetic taste status influences swallowing physiology and function. The purpose of this review article is to provide background on genetic taste status, review the evidence on the association between genetic taste status and swallowing, and discuss research and clinical implications.

METHOD

A comprehensive literature review was conducted using search terms related to swallowing and genetic taste status. Studies were included if they investigated the main effect of genetic taste status on swallowing or the interaction of genetic taste status with other variables. Studies were grouped by participant population (healthy participants or persons with a swallowing disorder), swallowing-related outcome measure, and method of genetic taste status measurement.

RESULTS

The results were mixed, with five of 10 reviewed studies reporting a statistically significant main or interaction effect on swallowing. Most studies included healthy participants, with only one study investigating participants with dysphagia. Additionally, swallowing-related outcome measures and methods of determining genetic taste status varied greatly between studies conducted on separate cohorts.

CONCLUSIONS

Few studies have incorporated genetic taste status as a variable in swallowing research, and results are mixed. Future research on sensation and swallowing should consider the potential effect of genetic taste status and follow standardized procedures for its determination. Despite the limited evidence, clinicians may consider how individual differences in perception shape swallowing outcomes.

Effects of Carbonated Water Concentration on Swallowing Function in Healthy Adults

In this study, we investigated the effects of carbonated water concentration on swallowing function using surface electromyography (sEMG). Healthy subjects (n = 52, 26.77 ± 3.21 years old) were asked to perform two swallows each of noncarbonated water, low-concentration carbonated water, medium-concentration carbonated water, and high-concentration carbonated water. Onset time, the mean sEMG activity amplitude, and duration of muscle activity in each swallow were measured and analyzed for orbicularis oris, masseter, submental muscle complex and infrahyoid muscles. Onset time significantly decreased and mean sEMG activity amplitude significantly increased with carbonation concentration. Therefore, stimulation with carbonation can be effective for modulating a faster and stronger swallow in the oral and pharyngeal phases of swallowing, and its effect on amplitude was greater in the oral phase than in the pharyngeal phase.Clinical Trials Registration This study is registered with Clinical Research Information Service (KCT0005925).

Effects of Food and Liquid Properties on Swallowing Physiology and Function in Adults

Foods and liquids have properties that are often modified as part of clinical dysphagia management to promote safe and efficient swallowing. However, recent studies have questioned whether this practice is supported by the evidence. To address this, a scoping review was conducted to answer the question: "Can properties of food and liquids modify swallowing physiology and function in adults?" Online search in six databases yielded a set of 4235 non-duplicate articles. Using COVIDENCE software, two independent reviewers screened the articles by title and abstract, and 229 full-text articles were selected for full-text review. One-hundred eleven studies met the inclusion criteria for qualitative synthesis and assessment of risk of bias. Three randomized controlled trials and 108 non-randomized studies were analyzed. Large amounts of variability in instrumental assessment, properties of food and liquids, and swallowing measures were found across studies. Sour, sweet, and salty taste, odor, carbonation, capsaicin, viscosity, hardness, adhesiveness, and cohesiveness were reported to modify the oral and pharyngeal phase of swallowing in both healthy participants and patients with dysphagia. Main swallow measures modified by properties of food and liquids were penetration/aspiration, oral transit time, lingual pressures, submental muscle contraction, oral and pharyngeal residue, hyoid and laryngeal movement, pharyngeal and upper esophageal sphincter pressures, and total swallow duration. The evidence pooled in this review supports the clinical practice of food texture and liquid consistency modification in the management of dysphagia with the caveat that all clinical endeavors must be undertaken with a clear rationale and patient-specific evidence that modifying food or liquid benefits swallow safety and efficiency while maintaining quality of life.

The effect of taste on swallowing: A scoping and systematic review

Consuming foods and liquids for nutrition requires the coordination of several muscles. Swallowing is triggered and modified by sensory inputs from the aerodigestive tract. Taste has recently received attention as a potential modulator of swallowing physiology, function, and neural activation; additionally, taste impairment is a sequela of COVID-19. This review presents factors impacting taste and swallowing, systematically summarizes the existing literature, and assesses the quality of included studies. A search was conducted for original research including taste stimulation, deglutition-related measure(s), and human participants. Study design, independent and dependent variables, and participant characteristics were coded; included studies were assessed for quality and risk of bias. Forty-eight articles were included after abstract and full-text review. Synthesis was complicated by variable sensory components of stimuli (taste category and intensity, pure taste vs. flavor, chemesthesis, volume/amount, consistency, temperature), participant characteristics, confounding variables such as genetic taster status, and methods of measurement. Most studies had a high risk of at least one type of bias and were of fair or poor quality. Interpretation is limited by wide variability in methods, taste stimulation, confounding factors, and lower-quality evidence. Existing studies suggest that taste can modulate swallowing, but more rigorous and standardized research is needed.

Effects of Carbonation on Swallowing: Systematic Review and Meta-Analysis

OBJECTIVES

The effectiveness of the use of carbonation in preventing penetration/aspiration or enhancing swallowing function in adults remains unclear. This systematic review aimed to evaluate the effectiveness of carbonation on improving swallowing function in adult subjects.

METHODS

Literature published before March 2021 was inspected using MEDLINE, CINAHL, Web of Science Core Collection, The Cochrane Library, Cochrane Central Register of Controlled Trials, and Ichushi-web databases. We searched for intervention studies or randomized control trials considering the effects of carbonated liquids on swallowing function. The risk of bias was assessed using the Cochrane tool for assessing the risk of bias for randomized controlled trials and the Risk of Bias Assessment Tool for Nonrandomized Studies.

RESULTS

The systematic review identified 19 studies with a total of 586 participants. The effects of carbonation on swallowing function are diverse. Overall, most studies showed that carbonation promotes swallowing function compared to other liquids. Five studies were included in the quantitative synthesis. Meta-analysis showed that carbonated liquids prevent aspiration (risk difference [RD] -0.27%, 95% confidence interval [CI] -0.44 to -0.10; I²  = 0%; number needed to treat 3.8, 95% CI 2.2 to 15.0; moderate quality of evidence) when compared to noncarbonated thin liquids. Carbonated liquids also increased the duration of swallowing apnea than did noncarbonated liquids (standardized mean difference 0.25 (mean difference 0.36 seconds), 95% CI 0.03 to 0.47; I²  = 0%; low quality of evidence).

CONCLUSIONS

Carbonation had favorable effects on swallowing function. Further in-depth studies are needed to clarify the benefits of carbonation.

LEVEL OF EVIDENCE

NA Laryngoscope, 2022.

Effects of carbonation of liquids on penetration-aspiration and residue management

Objective

Carbonation as a sensory enhancement strategy for prevention of aspiration of thin liquids has not been thoroughly studied. The aim of our study was to examine the effect of carbonation on penetration–aspiration and pharyngeal residue in dysphagia patients using Fiber-Optic Endoscopic Evaluation of Swallowing (FEES) and to identify parameters associated with a response to carbonation.

Methods

A cross-sectional study of patients undergoing FEES in a dysphagia clinic. Patients were offered 100 cc of dyed water. Penetration–aspiration was scored using the penetration–aspiration scale (PAS). Residue was scored using the Yale Pharyngeal Residue Severity Rating Scale (YPR-SRS). Patients with a PAS ≥ 2 for water were subsequently offered 100 cc of carbonated water. PAS, YPR-SRS and residue clearance were compared between thin and carbonated liquids. Multivariate logistic regression analysis was used to identify predictors for good response to carbonation.

Results

84 patients were enrolled, 77.4% males, with diverse dysphagia etiologies (58.3% neurogenic, 11.9% radiation-induced, 23.8% deconditioning-induced, and 6% neck surgery induced). Median PAS was 7 (IQR 4–8) for thin liquids and 4.5 (IQR 2–8) for carbonated liquids (P = 0.0001). YPR-SRS was reduced for carbonated compared to thin liquids in the vallecula (1.58 ± 0.83 vs 1.76 ± 0.93, P = 0.001) and piriform sinuses (1.5 ± 0.87 vs 1.67 ± 0.9, P = 0.002). 31 patients had improvement in PAS with carbonation. Deconditioning as a dysphagia etiology was found to predict good response to carbonation on multivariate logistic regression analysis.

Conclusion

Carbonation may prevent aspiration and improve residue management for some patients with dysphagia for liquids.

Level of evidence

IV.

An examination into the effect of genetic taste status and intensity of carbonation on swallowing and palatability in healthy young adults

BACKGROUND

Dysphagia is a highly prevalent condition and affects a wide range of cohorts. A common compensatory strategy to manage dysphagia is diet modification. However, this technique is often associated with poor patient quality of life and adverse long-term effects. Carbonated liquids have shown promise as an alternative compensatory strategy for the management of dysphagia.

AIMS

To examine the effect of genetic taste status and intensity of carbonation on swallowing and palatability in a healthy young adult population. To examine the palatability of carbonated liquids over time.

METHODS & PROCEDURES

A total of 35 healthy young adults were recruited for this prospective, quantitative cohort study. They each drank 150 ml of still water (SW), lightly carbonated water (LCW) and highly carbonated water (HCW). Swallow function, palatability and genetic taste status were assessed using the timed water swallow test, the hedonic general labelled magnitude scale and participant ratings of the bitterness of propylthiouracil strips, respectively. Participants were divided into groups of supertasters, moderate tasters and non-tasters.

OUTCOMES & RESULTS

A significant difference was found between SW and HCW on three tests of swallow function. Average time per swallow increased (p = 0.03), average swallow velocity decreased (p = 0.001) and average volume per swallow decreased (p = 0.017) on HCW compared with SW. HCW had a greater impact on swallow function than LCW. A significant mean difference in palatability ratings was found across intensity levels of carbonated fluids (p = 0.002), specifically between SW and HCW (p = 0.001). HCW was less palatable than SW. The palatability of carbonated liquids, investigated within a subgroup of five participants, did not decrease after a 24-h period during which participants only drank carbonated liquids (p = 0.102). A significant difference was found between supertasters' (n = 9) (mean = 13.33) and non-tasters' (n = 20) (mean = -24.5) palatability ratings of HCW (p = 0.03). Despite differences in swallow function between SW and HCW, no differences were detected between supertasters' and non-tasters' swallow function on SW, LCW or HCW.

CONCLUSIONS & IMPLICATIONS

Carbonated liquids have the ability to alter swallow function in a healthy young adult population; however, liquids must be highly carbonated in order to have an effect. Additionally, highly carbonated liquids are less palatable than SW, but the palatability of carbonated liquids does not decrease over time. Furthermore, supertasters find HCW more palatable than non-tasters. These findings suggest that carbonated liquids alter swallowing in a healthy population. Further research in a clinical population is needed to better understand the potential role of sensory stimulation as a dysphagia intervention.

WHAT THIS PAPER ADDS

What is already known on the subject Several studies have found that carbonated liquids have the ability to alter swallow function in both healthy and clinical populations. However, there is a lack of evidence around the optimum intensity of CO₂ in carbonated liquids and the palatability of carbonated liquids as well as the palatability of carbonated fluids over time. What this paper adds to existing knowledge The findings from this study suggest that carbonated liquids can alter swallow function in a healthy young adult population, but liquids must be highly carbonated in order to have an effect. HCW is less palatable than SW, but the palatability of carbonated liquids does not decrease over time. Additionally, supertasters find HCW more palatable than non-supertasters (non-tasters). What are the potential or actual clinical implications of this work? The findings from this study suggest that carbonated liquids may be suitable for use as a sensory stimulation technique for people with dysphagia, as their palatability does not decrease over time; however, further research in a clinical population is needed in order to determine this. Additionally, intensity of stimulus is an important factor to consider during dysphagia evaluation to identify what intensity is required to optimize swallowing.

Older US adults like sweetened colas, but not other chemesthetic beverages

Many older adults suffer from difficulty swallowing thin beverages like water or coffee. To improve swallowing safety, beverages are typically thickened. This creates a new problem: the thickened beverages can be disgusting. New research suggests chemesthesis, particularly spiciness, carbonation, or intense sourness, could improve swallowing without the need for thickeners. Yet, whether such beverages would be liked by older adults is unknown. We thus conducted this experiment to establish older adults' sensory perception and liking/disliking of commercially available chemesthetic beverages. We recruited participants to rate sweetness, sourness, fizziness, stinging, and liking/disliking of unsweetened carbonated waters (1 plain, 5 flavored), sour orange juice, spicy ginger beer, and colas (sugar or aspartame-sweetened). Initial tests (N = 30 older adults) indicated sour orange juice, spicy ginger beer, and two of the flavored waters were not well-liked, so other beverages were selected for a second test (N = 94, 30 younger adults, 64 older adults). Sweetened, carbonated colas were the best-liked of the beverages. The unsweetened, flavored carbonated waters were in general not liked. Regarding comparisons of sensory ratings between older and younger adults, only sweetness differed between age groups. In particular, intensity ratings for the chemesthetic aspects of the beverages (stinging/burning/spiciness, fizziness) and the sour taste did not differ by age. As the chemesthetic properties are the most likely reason the beverages could aid in swallowing safety, observing no suppression of these sensations in older adults is encouraging for the potential of these products as a treatment option.

Variations in the amplitude and duration of hyolaryngeal elevation during swallow: Effect of sour and carbonated liquid bolus

BACKGROUND

Altering sensory properties of food is relevant to the management of swallowing disorders. The current investigation aimed to examine the influence of sour and carbonated stimuli on measures of hyolaryngeal elevation.

METHOD

Sixty healthy adults in the age range of 18 to 35 years were assessed using Digital Accelerometry Swallowing Imaging (DASI) while swallowing 5 ml of neutral, sour and carbonated liquid bolus.

RESULTS

Sour stimulus was significantly different with higher amplitude and longer durational measures of hyolaryngeal elevation compared to the two other stimuli.

CONCLUSION

Sour stimulus facilitates better hyolaryngeal elevation, which implicates its usage in dysphagia management.

Ginger in gastrointestinal disorders: A systematic review of clinical trials

Ginger, the rhizome of Zingiber officinale, which is used as a spice globally has a long history of medicinal use that stimulates investigators to assess its potential roles as an adjuvant therapy or alternative medicine in a range of diseases. Anti-inflammatory, antioxidant, antitumor, and antiulcer effects of ginger have been proven in many scientific studies, and some of the ancient applications of ginger as a home remedy has been confirmed in human. In this review, we summarized the current evidence on the effects of ginger consumption on gastrointestinal disorders based on clinical trials. Our data indicate that divided lower daily dosage of 1500 mg ginger is beneficial for nausea relief. Because of limited number of studies on some other gastrointestinal disorders, the results may not be as much powered as to find significant results. Therefore, more extensive and well-controlled human studies of ginger or its standard extracts are required to demonstrate its efficacy as a gastroprotective agent. Dose-finding studies should be undertaken to accurately determine the effective dose and preparation of ginger in further clinical trials protocol.

Carbonation as a sensory enhancement strategy: a narrative synthesis of existing evidence

PURPOSE

Sensory enhancement techniques, like other compensatory strategies, aim to reduce dysphagia symptoms. The use of carbonated liquids has been proposed as a possible sensory technique, however to date, there is limited information of its efficacy or guidance for clinical implementation. A narrative synthesis was completed to determine the quality and strength of the evidence base for use of carbonation as a compensatory strategy in dysphagia rehabilitation.

METHODS

From 101 articles initially identified, 14 articles met the study criteria. Eleven papers described the effects of carbonation on swallowing in healthy participants whereas three described the impact of carbonation in dysphagic populations. A narrative synthesis of papers was undertaken given the diversity of identified studies.

RESULTS

Synthesis of findings was challenging given the exploratory phase of most research activity with diverse populations described and extensive differences in research methodologies. There is currently weak, but potentially positive evidence to support using carbonation as a compensatory technique in dysphagia rehabilitation.

CONCLUSION

Despite future potential, existing evidence fails to provide clear direction for the clinical implementation of carbonation. Validation of carbonation use with the dysphagic population requires further research with consistent, controlled methodologies, and larger cohorts of participants to inform potential for dysphagia rehabilitation. Implications for Rehabilitation The use of carbonated liquids has been proposed as a possible sensory enhancement technique which may facilitate changes to swallow physiology. However to date, there is limited information to direct clinical implementation. This paper provides a narrative synthesis of existing knowledge and highlights possible limitations of findings reported. Research to date has used disparate research methodologies in varied populations making synthesis of current findings challenging.

Analysis of carbonated thin liquids in pediatric neurogenic dysphagia

BACKGROUND

Aspiration of liquids is a serious complication of neurological impairments such as traumatic brain injury or stroke. Carbonated liquids have been examined as a possible alternative to thickened liquids to help reduce aspiration in cases of dysphagia in adults, but no published literature to the best of our knowledge has evaluated this technique in children. If carbonated liquids result in safer swallowing in children, they could provide a preferred alternative to thickened liquids.

OBJECTIVE

This pilot study examined whether carbonated thin liquids (CARB) improved swallowing compared to non-carbonated thin liquids (NOCARB) for children with neurogenic dysphagia.

MATERIALS AND METHODS

Twenty-four children admitted to a level I trauma center for acute neurological injury/disease were evaluated via videofluoroscopic swallow studies. Four descriptive outcome measures were contrasted.

RESULTS

CARB significantly decreased pooling (P = 0.0006), laryngeal penetration/aspiration (P = 0.0044) and Penetration-Aspiration Scale scores (P = 0.0127) when compared to NOCARB. On average, CARB improved scores on the Penetration-Aspiration Scale by 3.7 points for participants who aspirated NOCARB. There was no significant difference in pharyngeal residue noted between CARB and NOCARB (P = 0.0625).

CONCLUSION

These findings support the hypothesis that carbonated thin liquids may provide an alternative to thickened liquids for children with neurogenic dysphagia. Implications for future research and clinical practice are discussed.

Barium versus nonbarium stimuli: differences in taste intensity, chemesthesis, and swallowing behavior in healthy adult women

PURPOSE

The authors examined the impact of barium on the perceived taste intensity of 7 different liquid tastant stimuli and the modulatory effect that these differences in perceived taste intensity have on swallowing behaviors.

METHOD

Participants were 80 healthy women, stratified by age group (<40; >60) and genetic taste status (supertasters; nontasters). Perceived taste intensity and chemesthetic properties (fizziness; burning-stinging) were rated for 7 tastant solutions (each prepared with and without barium) using the general Labeled Magnitude Scale. Tongue-palate pressures and submental surface electromyography (sEMG) were simultaneously measured during swallowing of these same randomized liquids. Path analysis differentiated the effects of stimulus, genetic taste status, age, barium condition, taste intensity, and an effortful saliva swallow strength covariate on swallowing.

RESULTS

Barium stimuli were rated as having reduced taste intensity compared with nonbarium stimuli. Barium also dampened fizziness but did not influence burning-stinging sensation. The amplitudes of tongue-palate pressure or submental sEMG did not differ when swallowing barium versus nonbarium stimuli.

CONCLUSIONS

Despite impacting taste intensity, the addition of barium to liquid stimuli does not appear to alter behavioral parameters of swallowing. Barium solutions can be considered to elicit behaviors that are similar to those used with nonbarium liquids outside the assessment situation.

Influence of the perceived taste intensity of chemesthetic stimuli on swallowing parameters given age and genetic taste differences in healthy adult women

PURPOSE

This study examined whether the perceived taste intensity of liquids with chemesthetic properties influenced lingua-palatal pressures and submental surface electromyography (sEMG) in swallowing, compared with water.

METHOD

Swallowing was studied in 80 healthy women, stratified by age group and genetic taste status. General Labeled Magnitude Scale ratings of taste intensity were collected for deionized water; carbonated water; 2.7% w/v citric acid; and diluted ethanol. These stimuli were swallowed, with measurement of tongue-palate pressures and submental sEMG. Path analysis differentiated stimulus, genetic taste status, age, and perceived taste intensity effects on swallowing. Signal amplitude during effortful saliva swallowing served as a covariate representing participant strength.

RESULTS

Significant differences (p < .05) in taste intensity were seen across liquids: citric acid > ethanol > carbonated water > water. Supertasters perceived greater taste intensity than did nontasters. Lingua-palatal pressure and sEMG amplitudes were correlated with the strength covariate. Anterior palate pressures and sEMG amplitudes were significantly higher for the citric acid stimulus. Perceived taste intensity was a significant mediator of stimulus differences.

CONCLUSION

These data provide confirmatory evidence that high-intensity sour stimuli do influence swallowing behaviors. In addition, taste genetics influence the perception of taste intensity for stimuli with chemesthetic properties, which modulates behavioral responses.