What Type of Food Can Older Adults Masticate?: Evaluation of Mastication Performance Using Color-Changeable Chewing Gum

Effectiveness of the lay health advisor program on oral function and quality of life in aboriginal older adults: A randomized controlled trial

BACKGROUND

Aboriginal older adults residing in remote areas have poor oral function due to inadequate access to healthcare services. Lay health advisor (LHA) strategies can fill capacity shortages of healthcare professionals in rural communities and increase population acceptance of health care or healthy behaviours.

OBJECTIVE(S)

To evaluate the effectiveness the LHA program on oral function and oral health-related quality of life (OHRQoL) among older adults in aboriginal community.

METHODS

Participants were randomly assigned to an experimental group (EG; n = 122) and a control group (CG; n = 118). All participants performed oral exercises, and the EG received additional one-on-one 30-min lessons by an LHA over 4 weeks. Data were collected through face-to-face interview and oral examination. The generalized estimating equation model was used to analyse changes in outcomes over time.

RESULTS

The EG exhibited significantly greater improvement in swallowing (β = .63) at the 6-month follow-up and in masticatory performance (β = .52) and pronunciation of the syllable/pa/ (β = 2.65) at the 2-week follow-up than the CG did. The EG had a significantly lower plaque control record (β = -.14) and plaque index (β = -.30) at the 3-month follow-up than the CG did. Moreover, the OHRQoL was significantly increased at 6-months follow-up in the EG (p = .010).

CONCLUSION

The LHA program had positive effects on chewing, swallowing and plaque control in aboriginal older adults. LHA group also experienced positive long-term effect on OHRQoL after intervention.

The use of color-changeable chewing gum in evaluating food masticability

PURPOSE

We assess masticatory performance using color-changeable chewing gum, which shifts from yellow-green to red upon chewing. Previous studies used a colorimeter to reveal the cut-off a* values of the gum's color (a* represents the degree of color between red and green) to determine which foods are masticable (masticable meat, masticable soft side dish, and inadequate masticatory performance). Since a more convenient method is required, we examined the validity and reliability of visual measurement using a color scale to indicate masticable foods by observing the chewing gum's color.

METHODS

Fifty patients (male, 48%), aged ≥ 65 (mean, 82.6) years were enrolled. Using color-changeable chewing gum, three groups were formed according to the cut-off a* values: masticable meat, masticable soft side dish, and inadequate masticatory performance. For the color scale classification, one physiatrist and one dietitian simultaneously, individually, and visually determined the chewing gum color and classified it into one of the three groups. Criterion-related validity was evaluated using the kappa coefficient of agreement between the results from the two methods. Inter-rater reliability was examined using the kappa coefficient of agreement between the three groups judged by the two raters on a color scale.

RESULTS

The kappa coefficients of the agreement for the classifications were 0.908 and 0.909 for the physiatrist and dietitian, respectively. The inter-rater agreement between two raters on the color scale was 0.938 for the kappa coefficient.

CONCLUSION

The color scale indicated masticable foods without a colorimeter. This method can be useful in older adult facilities and homes.

Salmon protein gel enhancement for dysphagia diets: Konjac glucomannan and composite emulsions as texture modifiers

The growing prevalence of dysphagia among the aging population presents a significant challenge. Many highly nutritious foods, like salmon, are often unsuitable for the elderly due to their firm texture when heated. To address this concern, a combination of salmon myofibrillar protein (SMP), Konjac glucomannan (KGM), and different emulsion fillers-such as oil droplets, octenyl succinic anhydride (OSA)-modified potato starch emulsion, and high methoxylated pectin (HMP) emulsions-was selected to enhance the network of salmon protein gels with the aims to create potential applications as dysphagia-friendly foods. The International Dysphagia Dietary Standardization Initiative (IDDSI) test indicated that all gel samples were classified as level 5. The OSA-SMP-KGM gel exhibited notably higher cohesiveness (P < 0.05), reduced adhesion, and enhanced mouthfeel. The OSA-SMP-KGM gel exhibited a smooth surface and excellent water retention (92.4 %), rendering it suitable for individuals with swallowing difficulties, particularly those prone to experiencing dry mouth. The yield stress of OSA-SMP-KGM gel was 594.14 Pa and stable structure was maintained during chewing and swallowing (γe/γv = 62.5). This study serves as a valuable reference for developing salmon-based products that are not only highly nutritious but also fulfill the criteria for a desirable swallowing texture.

Chewing and its influence on swallowing, gastrointestinal and nutrition-related factors: a systematic review

The study aimed to evaluate the hypothesis that chewing is a mechanical and physiological contributor to swallowing, physiologic/pathologic processes of the gastrointestinal tract (GIT), and nutrition-related factors. A search strategy was applied to three different databases to investigate if chewing function in adults affects the swallowing, physiologic/pathologic processes of the GIT, and nutrition-related factors compared to controls with no exposure. The included studies were evaluated for methodological quality and risk of bias and certainty of evidence. The results showed 71 eligible studies. Overall, the results showed that 46 studies supported the hypothesis while 25 refuted it. However, the GRADE analysis showed low to very low certainty of the evidence to support the hypothesis that chewing is an important contributor in the swallowing process, and physiologic/pathologic processes in the GIT. The GRADE analysis also showed a moderate to very low certainty of the evidence to suggest that chewing function contributes to nutrition-related parameters. The overall results of the current study showed that a majority (64.7%) of the studies (46 out of 71) supported the hypothesis. However, robust studies with proper design, adequate sample size, and well-defined outcome parameters are needed to establish conclusive evidence.

Mechanical Properties, Microstructure, and In Vitro Digestion of Transglutaminase-Crosslinked Whey Protein and Potato Protein Hydrolysate Composite Gels

The production of animal protein usually leads to higher carbon emissions than that of plant protein. To reduce carbon emissions, the partial replacement of animal protein with plant protein has attracted extensive attention; however, little is known about using plant protein hydrolysates as a substitute. The potential application of 2 h-alcalase hydrolyzed potato protein hydrolysate (PPH) to displace whey protein isolate (WPI) during gel formation was demonstrated in this study. The effect of the ratios (8/5, 9/4, 10/3, 11/2, 12/1, and 13/0) of WPI to PPH on the mechanical properties, microstructure, and digestibility of composite WPI/PPH gels was investigated. Increasing the WPI ratio could improve the storage modulus (G') and loss modulus (G″) of composite gels. The springiness of gels with the WPH/PPH ratio of 10/3 and 8/5 was 0.82 and 0.36 times higher than that of the control (WPH/PPH ratio of 13/0) (p < 0.05). In contrast, the hardness of the control samples was 1.82 and 2.38 times higher than that of gels with the WPH/PPH ratio of 10/3 and 8/5 (p < 0.05). According to the International Organization for Standardization of Dysphagia Diet (IDDSI) testing, the composite gels belonged to food level 4 in the IDDSI framework. This suggested that composite gels could be acceptable to people with swallowing difficulties. Confocal laser scanning microscopy and scanning electron microscopy images illustrated that composite gels with a higher ratio of PPH displayed thicker gel skeletons and porous networks in the matrix. The water-holding capacity and swelling ratio of gels with the WPH/PPH ratio of 8/5 decreased by 12.4% and 40.8% when compared with the control (p < 0.05). Analysis of the swelling rate with the power law model indicated that water diffusion in composite gels belonged to non-Fickian transport. The results of amino acid release suggested that PPH improved the digestion of composite gels during the intestinal stage. The free amino group content of gels with the WPH/PPH ratio of 8/5 increased by 29.5% compared with the control (p < 0.05). Our results suggested that replacing WPI with PPH at the ratio of 8/5 could be the optimal selection for composite gels. The findings indicated that PPH could be used as a substitute for whey protein to develop new products for different consumers. Composite gels could deliver nutrients such as vitamins and minerals to develop snack foods for elders and children.

Study of occlusal acoustic parameters in assessing masticatory performance

Background

Previous masticatory studies have focused on a variety of measurements of foods and boluses or kinematic parameters and sound during mastication. To date, the masticatory sound research of has been limited due to the difficulties of sound collection and accurate analysis. Therefore, significant progress in masticatory sound has not been made. Meanwhile, the correlation between acoustic parameters and mastication performance remains unclear. For the purpose of exploring the acoustic parameters in measuring mastication performance, the bone-conduction techniques and sound analysis were used, and a statistical analysis of acoustic and occlusal parameters were conducted.

Methods

The gnathosonic and chewing sounds of fifty-six volunteers with healthy dentate were recorded by a bone-conduction microphone and further analyzed by Praat 5.4.04 when intercuspally occluding natural foods (peanuts) were consumed. The granulometry of the expectorated boluses from the peanuts was characterized by the median particle size of the whole chewing sequence (D50^a) and the median particle size during the fixed chewing strokes (D50^b). The chewing time of the whole chewing sequence (CT^a), the chewing time of the fixed chewing strokes (CT^b), the chewing cycles (CC), and the chewing frequency (CF) were recorded and analyzed by the acoustic software. The acoustic parameters, including gnathosonic pitch, gnathosonic intensity, mastication sound pitch of the whole chewing sequence (MP^a), mastication sound pitch of the fixed chewing strokes (MP^b), mastication sound intensity of the whole chewing sequence (MI^a) and mastication sound intensity of the fixed chewing strokes (MI^b), were analyzed. Independent sample t-test, Spearman and Pearson correlation analyses were used where applicable.

Results

Significant difference in parameters CC, MI^a, CF and D50^a were found by sex (t-test, p < 0.01). The masticatory degree of the test foods was higher in women (CC, 24.25 ± 5.23; CF, 1.70 ± 0.21 s⁻¹; D50^a, 1655.07 ± 346.21 μm) than in men (CC, 18.14 ± 6.38; CF, 1.48 ± 0.18 s⁻¹; D50^a, 2159.21 ± 441.26 μm). In the whole chewing sequence study, a highly negative correlation was found between MI^a and D50^a, and a highly positive correlation was found between MI^a and CF (r =  − 0.94, r = 0.82, respectively, p < 0.01). No significant correlation was found between the remaining acoustic parameters and mastication parameters. In the fixed chewing strokes study, a highly negative correlation was found between MI^b and D50^b (r =  − 0.85, p < 0.01). There was no significant correlation between the rest of the acoustic parameters and the mastication parameters.

Conclusions

Mastication sound intensity may be a valuable indicator for assessing mastication. Acoustic analysis can provide a more convenient and quick method of assessing mastication performance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-02018-9.

Physical Frailty and Oral Frailty Associated with Late-Life Depression in Community-Dwelling Older Adults

Late-life depression is a major mental health problem and constitutes a heavy public health burden. Frailty, an aging-related syndrome, is reciprocally related to depressive symptoms. This study investigated the associations of physical frailty and oral frailty with depression in older adults. This large-scale cross-sectional study included 1100 community-dwelling older adults in Taiwan. The participants completed a dental examination and questionnaires answered during personal interviews. The 15-item Geriatric Depression Scale was used to assess depression, and information on physical conditions and oral conditions was collected. Multivariable logistical regression analysis was conducted to examine associations of interest. Significant factors associated with depression were pre-physical frailty (adjusted odds ratio (aOR) = 3.61), physical frailty (aOR = 53.74), sarcopenia (aOR = 4.25), insomnia (aOR = 2.56), pre-oral frailty (aOR = 2.56), oral frailty (aOR = 4.89), dysphagia (aOR = 2.85), and xerostomia (aOR = 1.10). Depression exerted a combined effect on physical frailty and oral frailty (aOR = 36.81). Physical frailty and oral frailty were significantly associated with late-life depression in community-dwelling older adults in a dose–response manner. Developing physical and oral function interventions to prevent depression among older adults is essential.

Reliability and validity of a new colour-changing test food with an acid-base reaction for the clinical assessment of masticatory performance

The aim of this study was to determine the reliability and validity of a new test food for the clinical assessment of masticatory performance. The test food had two overlapping acidic/basic halves. Ten dentate subjects chewed one unit for 10-100 cycles. One subject chewed ten units for the same number of cycles. Differences in the L*, a* and b* colour axes were determined before and after chewing by ANOVA. Colour guides were created based on the values of these axes and matched with the number of cycles. The reliability of the guides was evaluated using 30 images, where three examiners indicated the number of cycles in which the colour closest to that of a chewed material was found. The data were contrasted with the real values of the guides to determine the validity (Kappa coefficients). The equivalence of the guides with the median particle size (X₅₀) was determined using equidimensional curves. The test food progressively changed from green to pink during chewing. As the number of cycles increased, the a* values increased and the b* values decreased (p < 0.05). Overall, the guides showed a Kappa value >0.8 for the intra-examiner and inter-examiner reliability and the validity comparisons. The a* and X₅₀ values were inversely proportional to each other, and the b* values showed a direct relationship with the X₅₀ values. The L* values did not show correspondence. The new test food showed high reliability and validity for the assessment of masticatory performance through clinical colour guides matched with the number of cycles and X₅₀.

Exploring Tools for Designing Dysphagia-Friendly Foods: A Review

Dysphagia is a medical condition that affects normal swallowing. To prevent the risk of aspiration or choking, thickened fluids and texture-modified foods have been used for dysphagia management with the goal of slowing down the flow of liquids and protecting the airway. This article summarizes the available information about the rheological and textural parameters, the characterization of the most-used thickeners and the application of alternative texture modification technologies that are crucial to developing safe dishes for people who suffer from swallowing difficulties. Regarding rheological and textural measurements, fundamental and empirical methods are described.

Association between the dental occlusion and perceived ability to eat foods of Taiwanese older adults

Tooth loss is a common problem among older adults that affects masticatory function (MF) and food selection. Financial burden is a reason that some older adults in Taiwan with this condition forgo dental restoration. To identify the number of posterior occlusal support areas (POSAs) associated with MF. Large-scale cross-sectional study included 1100 community-dwelling participants of Taiwan aged ≥65 years. Participants completed dental examination and questionnaires through personal interviews. Masticatory performance was evaluated using a colour-changeable chewing gum. Masticatory ability was evaluated on the basis of how many of 14 common foods the participants were able to eat. Participants were grouped into 10 categories (A1-A3, B1-B4 and C1-C3) according to the Eichner index (EI) of posterior occlusal contacts. Multivariable regression models were used to analyse the association between the EI groups and MF. More than 80% of the participants with two or more POSAs (those in groups A1-B2) could easily eat various foods. Compared with those in groups A1-B2, those in groups in B3, B4, C1, C2 and C3 exhibited a significantly different masticatory performance (all P < .001) and significantly higher difficulty in eating fruits and vegetables. A dose-response effect between POSAs and perceived masticatory ability to eat fruits and vegetables was observed (P < .05 for both trends). Preservation of at least two POSAs is essential for MF. Older adults with tooth loss can undergo the restoration of two POSAs to improve MF and increase food intake.

Bolus rheology of texture-modified food: Effect of degree of modification

Swallowing disorders, or dysphagia, require an intake of texture-modified foods progressively softer, smoother, and moister depending on the severity of the disorder. Bolus rheology was determined for five healthy subjects for a set of such solid foods regularly given to dysphagia patients. The softest class was gel food, then a smooth timbale which both were compared to the corresponding regular, un-modified food. The foods investigated were bread, cheese, tomato, and the combination as a sandwich, all for the respective texture class: gel, timbale, and regular food. The subjects chewed until ready to swallow and the expectorated bolus was immediately measured for complex shear modulus and viscosity, and moisture and saliva content were determined. Rheology show that texture-modification influenced bolus rheology with decreased viscosity and modulus for increased degree of modification. Also saliva content as well as chews-to-swallow decreased with degree of modification. Overall, the bolus saliva content was lower for the combination (sandwich) than for the individual components. Saliva content was fairly constant irrespective of food moisture content. The phase angle for all boluses was also relatively constant, indicating a similar bolus structure. All boluses of the texture-modified foods showed high extensional viscosity, which is important for bolus cohesiveness. Bolus rheology rather than food texture determines if a food is safe to swallow and the results show that the intended texture-modification is reflected in the flow properties of the respective boluses.

Dysphagia and masticatory performance as a mediator of the xerostomia to quality of life relation in the older population

Background

The impact of poor oral health on older adults’ quality of life is a public health problem. In this study, the mediating effects of dental status, occlusal condition, dysphagia, and masticatory performance on the association between xerostomia and oral health-related quality of life (OHRQoL) were assessed in the older adult population.

Methods

Stratified cluster sampling was used to recruit 1076 community-dwelling adults aged 65 years and older from Kaohsiung, Taiwan. Community care centers were randomly selected according to their geographic classifications (urban, rural, or mountainous areas). Assessments of dental status and occlusal condition were performed by dentists. Information on demographics, physical function, xerostomia, dysphagia and depression was collected through face-to-face interviews. Masticatory performance was evaluated using color-changeable chewing gum. OHRQoL was measured using the Geriatric Oral Health Assessment Index. Hierarchical regression models were used to assess the relationships between OHRQoL and physical function, dental status and oral function in older adults. Path analysis was used to estimate direct and indirect pathways between xerostomia and OHRQoL.

Results

Participants with xerostomia exhibited a 0.20 OHRQoL reduction (p < .001) compared with patients with no xerostomia, and the direct effect accounted for 83.3% of the total effect. Dysphagia and masticatory performance were found to exert significant mediating effects on the association between xerostomia and OHRQoL (βs = 0.20 and − 0.12, respectively; both p < .001; βs = 0.06 and − 0.09, respectively; both p < .05). Moreover, potential mediating effects of the number of functional teeth (βs = − 0.11 and − 0.43, respectively; both p < .001) and occlusal condition (βs = 0.09 and 0.13, respectively; both p < .05) on the relationship between xerostomia and masticatory performance were noted.

Conclusions

Dysphagia and masticatory performance may serve as pathways through which xerostomia affects quality of life. Early oral function intervention may be a valuable and actionable target for older adults to maintain quality of life. Our results further suggest that checkup and screening for oral dysfunction are essential to prevent or delay the onset of complications.

Supplied Food Consistency and Oral Functions of Institutionalized Elderly

Background

Maintaining good oral function is one of the goals of dental treatment. The Japanese national insurance system newly introduced the concept of management of oral function according to the life stage. For the application of management of oral functions of the elderly, seven kinds of examination is a must for the diagnosis: xerostomia, oral hygiene status, maximum occlusal pressure, tongue and labium function, tongue pressure, chewing ability, and swallowing function. We analyzed the relationship between oral functions and supplied food consistency.

Methods

Oral functions and supplied food consistency of sixty-nine institutionalized elderly were investigated. There were 13 men and 56 women, and their mean age was 86.23 ± 7.02. Oral functions were measured and evaluated according to the Japanese insurance system. Data were analyzed by item response theory analysis, ROC analysis, and decision analysis.

Results

By the item response theory analysis, tongue pressure and swallowing functions had high discrimination ability. The subjects who had malfunction of the tongue and labium all had processed food. The subjects with difficulty in swallowing, even without malfunction of the tongue and labium, all had processed food.

Conclusion

Supplied food consistency may depend on the oral functions. However, as oral function has some dimension, a systematic evaluation system is necessary to decide the supplied food consistency.

Swallowing function in advanced age

PURPOSE OF REVIEW

To present current literature regarding swallowing function in advanced age, including healthy ageing, dysphagia and trends in multidisciplinary team service delivery.

RECENT FINDINGS

Normative studies support swallowing efficiency but greater variability in healthy advanced age, through to 100 years old. Deviations from normative data and symptoms of dysphagia leading to aspiration or nutritional risk, imply swallowing disorder, rather than simply the ageing process. Quantitative and qualitative studies are emerging that promote management of swallow dysfunction for an ageing society, including innovative assessment, home treatment, swallowing exercise and optimized mealtimes.

SUMMARY

Current literature on swallowing function in advanced age provides multidisciplinary perspectives and initiatives, with clear commitment to improving quality of life for older adults. The diversity of the older population and serious consequences of swallowing difficulties calls for routine screening tools for swallowing impairment and malnutrition risk. Representation of 'oldest old' in future normative studies is essential to guide swallowing management in adults over 85 years old.

Systematic review of measurement properties of methods for objectively assessing masticatory performance

The objectives of this study is to identify methods for objectively assessing masticatory performance (MP) and to evaluate their measurement properties. A secondary objective was to identify any reported adverse events associated with the methods to assess MP. Bibliographic databases were searched, including MEDLINE, Embase, Web of Science Core Collection, Cochrane, and Cinahl databases. Eligible papers that satisfied predefined inclusion and exclusion criteria were appraised independently by two investigators. Four other investigators independently appraised any measurement properties of the assessment method according to the consensus-based standards for the selection of health measurement instruments checklist. The qualities of the measurement properties were evaluated using predefined criteria. The level of evidence was rated by using data synthesis for each MP assessment method, where the rating was a product of methodological quality and measurement properties quality. All studies were quality assessed separately, initially, and subsequently for each method. Studies that described the use of identical assessment method received an individual score, and the pooled sum score resulted in an overall evidence synthesis. The level of evidence was synthesized across studies with an overall conclusion, that is, unknown, conflicting, limited, moderate, or strong evidence. Forty-six out of 9,908 articles were appraised, and the assessment methods were categorized as comminution (n = 21), mixing ability (n = 23), or other methods (n = 2). Different measurement properties were identified, in decreasing order construct validity (n = 30), reliability (n = 22), measurement error (n = 9), criterion validity (n = 6), and responsiveness (n = 4). No adverse events associated with any assessment methods were reported. In a clinical setting or as a diagnostic method, there are no gold standard methods for assessing MP with a strong level of evidence for all measurement properties. All available assessment methods with variable level of evidence require lab-intensive equipment, such as sieves or digital image software. Clinical trials with sufficient sample size, to infer trueness and precision, are needed for evaluating diagnostic values of available methods for assessing masticatory performance.

Characterization of oral tactile sensitivity and masticatory performance across adulthood

Texture perception is one of the most important factors in food acceptance, yet population-wide differences in texture sensations are not well understood. The variation in texture perception across populations is thought to depend on oral tactile sensitivity and masticatory performance. To address this hypothesis, we aimed to measure tactile acuity with a battery of tests and quantitate the relationship to masticatory performance. The study was performed on 98 participants, in three age groups (20-25, 35-45, or over 62). Two main measures of oral sensitivity were performed: to assess bite force, subjects were asked to discriminate between foam samples of varying hardness. Second, to assess lingual sensitivity the subjects were asked to identify 3D printed shapes using their tongue, as well as identify confectionary letters. Additionally, masticatory performance was measured through assessing each participants ability to mix two-colored chewing gum. In general, we found that sensitivity and masticatory performance in the younger age groups was superior to that of older adults. We also found a positive linear trend between bite force sensitivity and masticatory performance with younger participants, a trend not found in older participants. We found no significant relationship between age groups for bite force sensitivity and masticatory performance, suggesting that age-related declines in bite force sensitivity are not a significant cause of altered masticatory performance. This study represents a valuable first step in showing that bite force sensitivity does not depend on age, and the minimal influence of factors such as oral sensitivity on masticatory performance. PRACTICAL APPLICATIONS: In a society that is rapidly aging, it is important to understand the subtle changes in physiology and eating behavior that are associated with aging. This study used a variety of tests oral sensitivity to better understand which aspects of oral physiology are integral for effective chewing. The information gained helps shed light on to the factors that create an effective chewing cycle. Besides moving knowledge forward, this study may help in designing food and rehabilitation programs for those with trouble chewing and swallowing, increasing their overall quality of life.

Optimizing Texture Modified Foods for Oro-pharyngeal Dysphagia: A Difficult but Possible Target?

Dysphagia is a swallowing disorder characterized by the difficulty in transferring solid foods and/or liquids from the oral cavity to the stomach, imparing autonomous, and safe oral feeding. The main problems deriving from dysphagia are tracheo-bronchial aspiration, aspiration pneumonia, malnutrition and dehydration. In order to overcome dysphagia-induced problems, over the years water and food thickening has been used, focusing specifically on viscosity increase, but limited results have been obtained. Elastic components and their effects on the cohesiveness on the bolus should be taken into account in the first place. We provide an analysis of dysphagia and suggest possible corrections to the protocols which are being used at present, taking into account rheological properties of food and the effect of saliva on the bolus. We reckon that considering such aspects in the dysphagia management market and healthcare catering would result in significant clinical risk reduction.