Bitter, Sweet, Salty, Sour and Umami Taste Perception Decreases with Age: Sex-Specific Analysis, Modulation by Genetic Variants and Taste-Preference Associations in 18 to 80 Year-Old Subjects

Self-Administered Taste Testing Without Water: Normative Data for the 53-Item Waterless Empirical Taste Test (WETT®)

BACKGROUND

According to the National Health and Nutrition Examination Survey (NHANES), more than 20 million Americans suffer from chronic taste problems. Unfortunately, quantitative testing is rarely performed, self-reports are inaccurate, and "taste" is often confused with olfaction-dependent flavors. Clearly, a reliable, practical, and norm-based clinical taste test is sorely needed.

METHODS

The recently developed 53-item Waterless Empirical Taste Test (WETT®) was self-administered by 1392 healthy subjects (493 men and 899 women) spanning the ages of 10-94. Normative percentile ranks were developed, and the influences of sex, age, COVID-19 infection history, and smoking behavior were evaluated using general linear models.

RESULTS

On average, WETT® scores declined with age beginning in the 30s and were lower in men than in women (ps < 0.0001), with the sex difference most apparent between 40 and 70 years of age. Subtest scores for the five basic taste qualities followed similar age- and sex-related patterns. No influences of COVID-19 history were evident. Smokers had lower salty (NaCl) and bitter (caffeine) WETT® scores than nonsmokers. The developed normative tables make it possible to determine a patient's absolute dysfunction score as well as a relative score based on age- and sex-related percentiles.

CONCLUSION

This study provides normative data based on 1392 healthy subjects for interpreting a patient's performance on a reliable self-administered taste test that requires no liquid stimuli or rinses. Its findings support the view that both sex and age are significant determinants of taste function in the general population.

A deadly taste: linking bitter taste receptors and apoptosis

Humans can perceive five canonical tastes: salty, sour, umami, sweet, and bitter. These tastes are transmitted through the activation of ion channels and receptors. Bitter taste receptors (Taste Family 2 Receptors; T2Rs) are a sub-family of 25 G-protein coupled receptor (GPCR) isoforms that were first identified in type II taste bud cells. T2Rs are activated by a broad array of bitter agonists, which cause an increase in intracellular calcium (Ca2+) and a decrease in cyclic adenosine 3',5'-monophosphate (cAMP). Interestingly, T2Rs are expressed beyond the oral cavity, where they play diverse non-taste roles in cell physiology and disease. Here, we summarize the literature that explores the role of T2Rs in apoptosis. Activation of T2Rs with bitter agonists induces apoptosis in several cancers, the airway epithelia, smooth muscle, and more. In many of these tissues, T2R activation causes mitochondrial Ca2+ overload, a main driver of apoptosis. This response may be a result of T2R cellular localization, nuclear Ca2+ mobilization and/or a remnant of the established immunological roles of T2Rs in other cell types. T2R-induced apoptosis could be pharmacologically leveraged to treat diseases of altered cellular proliferation. Future work must explore additional extra-oral T2R-expressing tissues for apoptotic responses, develop methods for in-vivo studies, and discover high affinity bitter agonists for clinical application.

Influence of masticatory function on food preferences and cognitive performance in centenarians: an observational study

INTRODUCTION

Demographic projections forecast that centenarians' population growth will continue. "CaT: Centenari a Trieste" is an ongoing study featuring the collection of demographic and anamnestic data, including the analysis of oral variables.

AIMS

evaluate of the possible influence of past food preferences, taste perception and masticatory function on current cognitive status in a cohort of centenarians.

DESIGN

Observational transversal study.

MATERIALS AND METHODS

31 participants with mean age 102 ± 2 performed an examination of the oral cavity including the measurement of DMFT (Decayed Missing Filled Teeth), FTUs (functional teeth units), FOUs (functional occlusal units) and 6-n-propylthiouracil (PROP) taste perception assay. Results were correlated with dementia, subjective perception of oral health and food preferences.

RESULTS

Masticatory function did not correlate with dementia but had a significant impact on oral health perception. When analyzing variables affecting food preferences, PROP taste perception profile and DMFT resulted significantly correlated. Early edentulism didn't show to affect past dietary preferences.

CONCLUSIONS

our data suggest that in centenarians masticatory function doesn't seem to correlate to cognitive function, but influences the self-perception of oral health. Such results are an interesting addition to knowledge on the topic as they refer to a population which has never been considered before.

From Liking to Following: The Role of Food Preferences, Taste Perception, and Lifestyle Factors in Adherence to the Mediterranean Diet Among Young Individuals

BACKGROUND AND AIMS

The Mediterranean diet (MedDiet) is a healthy dietary pattern associated with reduced risk of chronic diseases. However, adherence is declining, particularly among younger populations. Therefore, it is crucial to identify the main aspects that affect its adherence, particularly food preferences and sensory function, which have received insufficient attention. Our aims were to investigate the impact of socio-demographic and lifestyle factors on adherence to the MedDiet among young individuals; to assess the association of taste preferences and food liking with MedDiet adherence; and to evaluate the associations between taste perception modalities, taste and food preferences, and adherence.

METHODS

A cross-sectional study on young adults (aged 20.5 ± 4.7 years) in a Mediterranean country (n = 879) was carried out. Demographic characteristics, clinical characteristics, anthropometric characteristics, lifestyle characteristics, MedDiet adherence, taste preferences, and food preferences were assessed. Taste perception for bitter, salty, sweet, sour, and umami was determined by rating different concentrations of prototypical tastants. We computed a total taste perception score and three scores to combine food preferences.

RESULTS

We identified several socio-demographic and lifestyle factors associated with adherence to the MedDiet, as well as food preferences, taste preferences, and taste perception determinants. Food preferences were significantly associated with total adherence to the MedDiet. Higher preference for olive oil, oranges, broccoli, fish, and legumes was associated with higher MedDiet adherence (p < 0.05 for all). Conversely, higher preference for sweet foods, red meat, and butter was associated with lower adherence (p < 0.05 for all). The combined positive score for food preference was strongly associated with higher MedDiet adherence (p = 1.4 × 10-23) in the multivariate adjusted model. The combined negative food preference score was inversely associated (p = 1.9 × 10-8). Likewise, taste preferences were significantly associated with adherence to the MedDiet (strong inverse association for sweet taste preference and direct association for bitter taste preference; both p < 0.001). Moreover, bitter taste perception was inversely associated with adherence to the MedDiet and with bitter foods (p < 0.05). In conclusion, future precision nutrition studies should measure food liking and taste preferences, which are crucial determinants of MedDiet adherence, especially in young people.

Sex differences in diet-mediated salivary protein upregulation

Our lab previously established that repeated exposure to a bitter diet can increase salivary protein (SP) expression, which corresponds to an increase in acceptance of the bitter stimulus. However, this work was exclusively in male rodents, here we examine sex differences. We found that there are no differences in SP expression (experiment 1) or quinine diet acceptance (experiment 2) across stage of estrous cycle. Yet, males and females differ in feeding behaviors, SP expression, and responses to a quinine diet (experiment 3). On a quinine diet, males accepted the diet much faster than females. Males displayed a compensatory increase in meal number as meal size and rate of feeding decreased with initial exposure to a quinine diet, whereas females decreased meal size and rate of feeding with no compensation in meal number. There were sex differences in SP expression at day 14 of quinine exposure but these were gone by day 24. Both sexes increased acceptance of quinine in a brief access taste test after the feeding trial concluded. These data suggest that males and females have different patterns of bitter diet acceptance, but extended exposure to quinine diet still results in altered bitter taste responding and changes in SP profiles in females.

TAS1R2 rs35874116 Associations with Taste, Diet, and Health in an Italian Population

BACKGROUND/OBJECTIVES

The TAS1R2 SNP rs35874116 has previously been associated with sweet taste, diet, and health status, although never comprehensively in a single study. Also, associations between TAS1R2 and sweet taste might be body mass index (BMI)-dependent. Therefore, this study aimed to conduct a comprehensive investigation of rs35874116 and sweet taste intensity and liking, food liking, and diet and health status whilst considering BMI.

METHODS

Five-hundred and fifty-four participants were recruited. Linear regression models were used to explore rs35874116 associations with sweet taste intensity and liking, food liking, and diet and health status. A secondary analysis stratified participants by BMI <25/≥25 kg/m2.

RESULTS

The rs35874116 wildtype was associated with increased sweet taste intensity (p = 0.0345, B 1.29, SE 0.61) and liking (p = 0.021, B 0.25, SE 0.11). However, these associations only remained in BMI ≥25 individuals (intensity: p = 0.037, B 1.29, SE 0.61, liking: p = 0.008, B 0.46, SE 0.17). It was also associated with decreased diet quality (p = 0.03, B -0.27, SE 0.13) and reduced free sugar consumption but increased saturated fat consumption in BMI ≥25 individuals (free sugars: p = 0.0416, B -0.8, SE 0.38, saturated fat: p = 0.031, B 1.38, SE 0.62). There was no association with the mean liking score for sweet foods, although there were some associations with individual foods, which require further investigation. There were no associations with health status.

CONCLUSIONS

This study revealed an association between the rs35874116 wildtype and an increased intensity and liking of the sweet taste and a corresponding worse overall dietary quality. This study adds to previous evidence regarding how associations between TAS1R2 and sweet taste are BMI-dependent.

T1R2/T1R3 polymorphism affects sweet and fat perception: Correlation between SNP and BMI in the context of obesity development

Genetic variations in taste receptors are associated with gustatory perception and obesity, which in turn affects dietary preferences. Given the increasing tendency of people with obesity choosing sweet, high-fat meals, the current study assessed the cross-regulation of two polymorphisms of the sweet taste receptor (T1R2/T1R3), rs35874116 and rs307355, on fat sensitivity in Indian adults. We investigated the association between taste sensitivity and BMI in the T1R2, T1R3, and CD36 polymorphic and non-polymorphic groups. The general labelled magnitude scale (gLMS) was used to assess the taste sensitivity of 249 participants in addition to anthropometric data. TaqMan Probe-based RT-PCR was employed to determine the polymorphisms. Additionally, the colorimetric method utilizing 3, 5-dinitro salicylic acid was used to evaluate the participants' salivary amylase activity. The mean detection thresholds for linoleic acid (LA) and sucrose were greater in individuals with obesity (i.e., 0.97 ± 0.08 mM and 0.22 ± 0.02 M, respectively) than in healthy adults (p < 0.0001), indicating lower sensitivity. Moreover, it was found that a greater proportion of persons with obesity fall into the polymorphic groups (i.e., 52% with genotype CD36 AA, 44% with genotype T1R2 CC, and 40% with genotype T1R3 TT). All three single nucleotide polymorphisms support the Hardy-Weinberg equilibrium (p = 0.78). The Pearson correlation analysis between LA and the sucrose detection threshold revealed a significant (p < 0.0001) positive relationship with an r value of 0.5299. Moreover, salivary amylase activity was significantly (p < 0.05) higher in the polymorphic sub-groups. The results of our study imply that genetic variations in T1R2/T1R3 receptors affect perception of both sweetness and fat, which may have an effect on obesity.

[Causes of taste hyposensitivity in daily life and health risks: including the taste of ‍fatty acids]

The sensory system detects the internal and external environment of the body and the stimulus trigger feedback loops toward the set point to maintain homeostasis, but if taste sensitivity has changed, we may consume more nutrients or loss of appetite. These can lead metabolic syndrome or malnutrition, which can lead to frailty. In this review, we examined which of the five basic tastes (sweet, umami, bitter, sour, and salty) is affected by aging. Next, we summarize the effects of oral bacteria and tongue coating on taste, which can cause problems such as bad breath and aspiration pneumonia. Even healthy people can change their taste sensitivity and pose health risks if they continue to eat certain taste substances on a daily basis. Furthermore, we summarize research from the discovery of the taste of fatty acids to the present, and discuss how the involvement of taste in food intake regulation contributes to homeostasis through a literature survey. Recently, a gut-brain circuit for fat preference has been identified. In the intestine, fatty acids are sensed by the same receptors as those in the taste buds of the tongue, and nutritional information is sent to the brain via the vagus nerve. It is very interesting that nerves that convey fatty acid-specific information have been discovered. In this way, taste system of the tongue and nutrition-sensing in the digestive tract are very similar, so we think it will be very meaningful to progress research by referring to each other.

Perception of Sour Taste in Subjects with Olfactory Deficits: Role of Myrtle Aromatization

BACKGROUND

Sour taste is associated with acid-base homeostasis, which is critical to cell metabolism and health conditions. Vinegar, which contains acetic acid as the main component, is a sour food considered the second most common condiment in Italy.

OBJECTIVES

The aim of the study was to assess differences in sourness perception in subjects with olfactory deficits compared to controls and evaluate myrtle aromatization's potential effect in modulating sourness perception in subjects with hyposmia.

METHODS

To this end, olfactory function was assessed with the Sniffin' Sticks test and gustatory function by the Taste Strips test. Sensory perception of a traditional white wine vinegar (WV) and a WV aromatized with myrtle (AWV) was evaluated. The sourness perception of the two vinegars was estimated through the rates of odor and taste pleasantness, intensity, and familiarity using a labeled hedonic Likert-type scale.

RESULTS

Our data indicated that in patients with hyposmia, a significant decrease was observed only in sour taste perception compared to controls. The increase in vinegar aroma due to the myrtle aromatization modulated sourness perception in patients with hyposmia.

CONCLUSIONS

Myrtle aromatization increased the number of significant correlations between odor and the taste dimensions of the vinegar in controls and in patients with hyposmia in a different manner.

A Survey on the Evaluation of Monosodium Glutamate (MSG) Taste in Austria

The umami taste is well validated in Asian culture but remains less recognized and accepted in European cultures despite its presence in natural local products. This study explored the sensory and emotional perceptions of umami in 233 Austrian participants who had lived in Austria for most of their lives. Using blind tasting, participants evaluated monosodium glutamate (MSG) dissolved in water, providing open-ended verbal descriptions, pleasantness ratings, and comparisons to a sodium chloride (NaCl) solution. Discrimination tests excluded MSG ageusia, and basic demographic data were collected. A text semantic-based analysis (TSA) was employed to analyze the emotional valence and descriptive content of participants' responses. The results showed that MSG was predominantly associated with neutral sentiments across the group, including both female and male subgroups. "Sour" was the most frequent taste descriptor, while "unfamiliar" characterized the perceptual experience. Pleasantness ratings for MSG and NaCl were positively correlated, suggesting that overcoming the unfamiliarity of umami could enhance its acceptance and align it with the pleasantness of salt. These findings advance the understanding of umami sensory perception and its emotional and cultural acceptance in European contexts, offering valuable insights for integrating umami into Western dietary and sensory frameworks.

Changes in taste perception in elderly population and its potential impact on oral health: a systematic review with meta-analysis

Aim

Gustatory function plays a fundamental role in various aspects related to nutrition and health, and the decline in taste perception can result in a series of adverse consequences. This is expected with aging due to a decrease in taste buds and other conditions, leading to systemic and oral diseases. We aimed to compare taste sensitivity in the elderly population vs. adults.

Methods

This systematic review was reported according to PRISMA guidelines. The search was performed in four databases, as well as in grey literature. The risk of bias was assessed using the JBI's critical appraisal tools for observational studies. A meta-analysis with subgroups according to each flavor was conducted to obtain differences in means for adults vs. elderly (random-effects model).

Results

Out of the 5,660 studies retrieved, 18 observational studies were included, representing a total of 1,680 aged 18-59 years and 1,048 aged ≥ 60 years. Elderly individuals need higher concentrations to distinguish flavors compared to adults. In a qualitative analysis, all flavors showed differences between the groups, with sweet flavor being the easiest to recognize and the thresholds between the groups not being highly discrepant. However, in the meta-analysis, statistical differences were observed for sweet, salty, and umami flavors, while there were no statistical differences for sour and bitter flavors between the groups.

Conclusions

There are significant differences for distinguishing sweet, salty, and umami flavors between adults and elderly. Bitter and sour flavors did not exhibit differences in elderly.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=463873, PROSPERO (CRD42023463873).

Identifying sources of variation in added sugar intake for Alaska Native children using a hair biomarker

Sugars from sugar-sweetened beverages (SSBs) are an important risk factor for tooth decay. The study goal was to determine if there was variation in added sugar intake across communities and between and within households. In this cross-sectional study, intakes of total sugar, added sugar, and sugar-sweetened beverages (SSBs) were estimated for 282 Alaska Native children ages 0-10 years from 131 households in three Yukon-Kuskokwim (YK) Delta communities using biomarker equations based on hair carbon and nitrogen isotope ratios previously developed for the Yup'ik population. ANOVA was used to assess associations between each predictor (community and household) and outcome (estimated total sugars, added sugars, and SSB intake). Between- and within-household variation was estimated using a linear mixed-effects model with a random intercept for households with three or more children. There was no significant difference in mean estimated total sugar (p = 0.29), added sugar (p = 0.24), or SSB intake (p = 0.40) across communities. Significant variations were observed between and within households, with within-household variation amounting to 59% of the between-household variation. Added sugar intake in Alaska Native children from the three study communities is higher than the recommended maximum, and the variation is greater within households than between households.

Effective method for life-style modifications focused on dietary sodium intake in chronic kidney disease: sub-analysis of the FROM-J study

BACKGROUND

Lifestyle modifications by educational sessions are an important component of multidisciplinary treatment for chronic kidney disease (CKD). We attempted to identify the best method to teach these modifications in order to ensure their acceptance by patients and investigated its effectiveness in CKD practice.

METHODS

This study is a post-hoc analysis of the FROM-J study. Subjects were 876 CKD patients in the advanced care group of the FROM-J study who had received lifestyle modification sessions every 3 months for 3.5 years. Two-hundred and ten males (32.6%) and 89 females (38.2%) showed success in sodium restriction. In this study, we examined factors affecting sodium restriction in these subjects.

RESULTS

Subjects received three or more consecutive educational sessions about improvement of salt intake. The median salt-intake improvement maintenance period was 407 days. The number of dietary counseling sessions (OR 1.090, 95%CI: 1.012-1.174) in males and the number of dietary counseling sessions (OR 1.159, 95%CI: 1.019-1.318), CKD stage progression (OR 1.658, 95%CI: 1.177-2.335), and collaboration with a nephrologist (OR 2.060, 95%CI: 1.073-3.956) in females were identified as significant factors improving salt intake. The only factor contributing to the maintenance of improved salt intake was the continuation of dietary counseling (p = 0.013).

CONCLUSION

An increased number of educational sessions was the only successful approach for males to implement and maintain an improved salt intake. Providing the resources for continuous counseling is beneficial for lifestyle modifications and their maintenance in the long-term management of CKD. Continuous counseling for lifestyle modifications is highly cost-effective.

TRIAL REGISTRATION

The FROM-J study was registered in UMIN000001159 on 16/05/2008.

Decreased Tongue-Lip Motor Function in Japanese Population with Low Taste Sensitivity: A Cross-Sectional Study

Background/Objectives: Taste disorders have a negative impact on meal enjoyment, which is essential for maintaining adequate nutrition and quality of life. Japan is a rapidly aging society with an increasing number of individuals with taste disorders. However, despite the increasing prevalence of taste disorders, the correlation between oral frailty and taste sensitivity remains largely unknown. The objective of this study was to assess the relationship between oral health status and taste sensitivity among the Japanese population. Methods: Participants were recruited from Kanagawa Dental University Hospital Medical-Dental Collaboration Center between 2018 and 2021. The exclusion criteria were severe systemic infections, pregnancy, or lactation. Clinical examinations, oral function assessments, and taste tests were conducted using tap water and 1% sweet, 0.3% salty, 0.03% umami, and 0.1% umami tastants. The relationships between oral function, systemic indicators, and taste sensitivity were statistically evaluated. Results: Of the 169 participants included in this cross-sectional study, 39.6% were male and 60.4% were female (median age, 68 years). Participants with low taste sensitivity showed a decline in tongue-lip motor function, independent of age, sex, or smoking status. A multiple logistic regression analysis conducted using two age categories-younger than 65 years and older than 65 years-revealed an association between tongue-lip motor function and taste sensitivity among participants younger than 65 years. Conclusions: Decreased taste sensitivity is associated with tongue-lip motor function. Therefore, the early maintenance of oral function and taste sensitivity may be beneficial for optimal tongue-lip motor function.

Pharmacodynamics, pharmacokinetics and CYP3A4 interaction potential of the selective P2X3 receptor antagonist filapixant: A randomized multiple ascending-dose study in healthy young men

AIMS

We report on investigations exploring the P2X3-receptor antagonist filapixant's effect on taste perception and cough-reflex sensitivity and describe its pharmacokinetics, including its CYP3A4-interaction potential.

METHODS

In a randomized, placebo-controlled, double-blind study, 3 × 12 healthy men (18-45 years) were assigned (3:1) to filapixant (20, 80 or 250 mg by mouth) or placebo twice daily over 2 weeks. A single dose of midazolam (1 mg), a CYP3A4 substrate, was administered with and without filapixant. Assessments included a taste-strips test, a taste questionnaire, cough challenge with adenosine triphosphate, adverse event reports and standard safety assessments.

RESULTS

Taste disturbances were observed mainly in the 250-mg group: six of nine participants (67%) in this group reported hypo- or dysgeusia in the questionnaire; eight participants (89%) reported taste-related adverse events. Five participants (56%) had a decrease in overall taste-strips-test scores ≥2 points (point estimate -1.1 points, 90% confidence interval [-3.3; 1.1]). Cough counts increased with adenosine triphosphate concentration but without major differences between treatments. Filapixant exposure increased proportionally to dose. Co-administration of filapixant had no clinically relevant effect on midazolam pharmacokinetics. Area under the concentration-time curve ratios and 90% confidence intervals were within 80-125%. No serious or severe adverse events were reported.

CONCLUSIONS

Overall, filapixant was safe and well tolerated, apart from mild, transient taste disturbances. Such disturbances occurred more frequently than expected based on (in vitro) receptor-selectivity data, suggesting that other factors than P2X3:P2X2/3 selectivity might also play an important role in this context. The cough-challenge test showed no clear treatment effect. Filapixant has no clinically relevant CYP3A4 interaction potential.

Novel Perspective on the Plasticity of Taste Perception: Is Food- and Exercise-Induced Inflammation Associated with Sweet Taste Sensitivity and Preference?

Obesity-related inflammation has been linked to decreased taste sensitivity and changes in the transcriptome of the taste apparatus. Increased levels of pro-inflammatory cytokines can also be found to be food-associated in individuals who consume high amounts of long-chain saturated fatty acids and sucrose independent of the body composition or individuals who exercise intensively. Previous research suggests a link between taste sensitivity and food choices. However, the interplay between food- or exercise-induced low-grade inflammation, taste perception, and food choices remains unaddressed. Understanding this relationship could provide an unnoticed explanation for interindividual differences in taste perception that influences dietary habits.

The evaluation of clinical factors affecting oral health impacts on the quality of life of Iranian elderly patients visiting dental clinics: A cross-sectional study

BACKGROUND

Iran will soon have an aging population. Healthcare providers must consider factors affecting the quality of life for those 60 and older. Understanding oral health as one of these factors can improve the elderly's quality of life. Oral health-related quality of life (OHRQoL) is a crucial reflection of individuals' general well-being and their overall quality of life linked to health. This study aimed to evaluate the OHRQoL among elderly Iranians referring to Azad University of Medical Sciences in Tehran.

METHODS

In this cross-sectional study, 171 individuals over 65 (93 men and 78 women) were evaluated using OHIP-14 and GOHAI-12 questionnaires to analyze their quality of life. Gender, age, systemic diseases, using medications and dentures, the number of remaining teeth, and oral lesions were recorded. Salivary flow and xerostomia were analyzed with the spitting method and xerostomia index questionnaire, respectively. Also, four main flavor solutions were used to evaluate the taste perception. Data were analyzed using PASS11 and p value < .05 was the significance level.

RESULTS

Based on OHIP-14 and GOHAI-12, Iranian older people's quality of life can be affected by cardiovascular diseases, hypertension, xerostomia, and the number of remaining teeth (p < .05). The results also showed a significant correlation between the OHIP-14 and GOHAI-12 scores (p < .001). Both indexes revealed that the number of remaining teeth, xerostomia, salivary flow, and taste perception greatly influenced participants' quality of life. More remaining teeth, improved salivary flow, and better perception of sweetness and sourness were all linked to a higher quality of life, while increased xerostomia, reduced salivary flow, and bitter taste perception were linked to a decline in overall well-being. Cardiovascular diseases, hypertension, and medication use were also found to significantly impact quality of life.

CONCLUSION

This study's results indicate that cardiovascular diseases, hypertension, dry mouth, and tooth loss can negatively impact the elderly's quality of life. So, improving both systemic and oral health is vital for enhancing life quality in this age group.

The effect of mango aroma in low-sugar beverage: A sensory study on odor induced sweetness enhancement

Excessive intake of sugar has become a public concern. However, it is challenging for food industries to decrease sugar level without sacrificing safety and sensory profile. Odor-induced sweetness enhancement (OISE) is believed to be a novel and promising strategy for sugar reduction. In order to investigate the OISE effect of mango aroma and evaluate its degree of sugar reduction in low-sugar beverages, a mathematical model was constructed through sensory evaluation in this study. The results showed that the maximum liking of low-sugar model beverages was 4.28 % sucrose and 0.57 % mango flavor. The most synergistic of OISE was at the concentration level of 2.24 % sucrose + 0.25 % mango flavor, which was equivalent to 2.96 % pure sucrose solution. With 32.14 % sugar reduction, the mango aroma was suggested to generate the OISE effect. However, the same level of garlic aroma was not able to enhance sweetness perception, suggesting that the congruency of aroma and taste is a prerequisite for the OISE effect to occur. This study demonstrated that the cross-modal interaction of mango aroma on sweetness enhancement in low-sugar model beverages could provide practical guidance for developing sugar-reduced beverages without applying sweeteners.

Long-COVID impacts taste and olfactory in individuals with substance use disorder: A retrospective cohort study from the TriNetX US Collaborative Networks

Substance use disorder (SUD) exacerbates the impact of Long-COVID, particularly increasing the risk of taste and olfactory disorders. Analyzing retrospective cohort data from TriNetX and over 33 million records (Jan 2020-Dec 2022), this study focused on 1,512,358 participants, revealing that SUD significantly heightens the likelihood of experiencing taste disturbances and anosmia in Long-COVID sufferers. Results indicated that individuals with SUD face a higher incidence of sensory impairments compared to controls, with older adults and women being particularly vulnerable. Smokers with SUD were found to have an increased risk of olfactory and taste dysfunctions. The findings underscore the importance of early screening, diagnosis, and interventions for Long-COVID patients with a history of SUD, suggesting a need for clinicians to monitor for depression and anxiety linked to sensory dysfunction for comprehensive care.

Dietary salt intake and kidney function in rural Senegalese populations: a cross-sectional study

INTRODUCTION

High salt intake is a major risk factor for hypertension and its complications such as chronic kidney disease (CKD) and cardiovascular diseases. The present study aimed to determine level of sodium consumption and its relation with kidney function in the rural populations of Ferlo (centre of Senegal).

SUBJECTS AND METHODS

We performed a cross-sectional study including 400 volunteers aged > 18 years. Clinical, biological and dietary data were collected during household visits. Daily sodium intake was measured in the 24 h-urine outpout and CKD was defined as eGFR < 60 ml/min. Linear regression analysis was used to assess association between sodium intake and covariates.

RESULTS

Mean age was 46.42 ± 15.60 and sex-ratio was 1.05. Prevalence of hypertension, CKD and overweight were 21.5, 11.7 and 20.5%, respectively. The median daily salt intake was 11.7 g with interquartile range of 14.8 g. Only 11.25% of participants consumed less than 5 g/day. After multivariate analysis, high salt intake was associated with age > 60 years, overweight and CKD. However, gender and hypertension were not significantly associated with salt intake. Industrial broths (91.5%) and bread (85%) represented the main sources of dietary salt.

CONCLUSION

This study revealed high levels of daily salt intake contrasting with low potassium intakes in the majority of participants. Participants with CKD, overweight and age > 60 years presented higher salt consumption. Stategies to reduce salt consumption are urgently needed to reduce burden of CKD in rural Senegalese populations.

The gustin gene variation at rs2274333 and PROP taster status affect dietary fat perception: a stepwise multiple regression model study

Gustin, a trophic factor for taste bud development, and its polymorphism at rs2274333 influence taste perception of 6-n-propylthiouracil (PROP) and fungiform papillae (FP) density. The PROP taster status affects dietary fat sensing and body composition. However, there is a paucity of research on the gustin genotype with dietary fat perception, PROP tasting ability, and body mass index (BMI). Thus, taste sensitivity to fat and bitterness was evaluated in 178 healthy individuals. The general labeled magnitude scale was used to determine suprathreshold taste intensity ratings, whereas the alternative forced choice approach was used to estimate the taste-sensing ability. The FP density was assessed by applying blue-colored food dye over the anterior region of the tongue. Restriction fragment length polymorphism was used to detect the genetic polymorphism (rs2274333) in the carbonic anhydrase VI (CA-VI) gene. Fisher's chi-square analysis showed that the CA-VI genotype and allelic frequencies significantly correlated (p<0.001) with the PROP taster status and BMI. Healthy individuals with AA genotypes of the CA-VI polymorphism and PROP super-tasters demonstrated stronger gustatory sensitivity for linoleic acid (LA) with greater FP density in comparison to individuals with AG/GG genotypes and other PROP taster groups. Stepwise forward multiple regression analysis indicates that BMI and PROP taster status significantly influence the LA sensing ability. The suprathreshold intensity rating for LA was also significantly impacted by PROP taster status and CA-VI genotypes, with a variation of 73.3%. Overall, our findings show a relationship between the taste papillae environment and the CA-VI genetic mutation at rs2274333, which influenced the gustatory preference for dietary fat and bitter taste.

The Obese Taste Bud study: Objectives and study design

AIMS

Taste modifies eating behaviour, impacting body weight and potentially obesity development. The Obese Taste Bud (OTB) Study is a prospective cohort study launched in 2020 at the University of Leipzig Obesity Centre in cooperation with the HI-MAG Institute. OTB will test the hypothesis that taste cell homeostasis and taste perception are linked to obesity. Here, we provide the study design, data collection process and baseline characteristics.

MATERIALS AND METHODS

Participants presenting overweight, obesity or normal weight undergo taste and smell tests, anthropometric, and taste bud density (TBD) assessment on Day 1. Information on physical and mental health, eating behaviour, physical activity, and dental hygiene are obtained, while biomaterial (saliva, tongue swap, blood) is collected in the fasted state. Further blood samples are taken during a glucose tolerance test. A stool sample is collected at home prior to Day 2, on which a taste bud biopsy follows dental examination. A subsample undergoes functional magnetic resonance imaging while exposed to eating-related cognitive tasks. Follow-up investigations after conventional weight loss interventions and bariatric surgery will be included.

RESULTS

Initial results show that glycated haemoglobin levels and age are negatively associated with TBD, while an unfavourable metabolic profile, current dieting, and vegan diet are related to taste perception. Olfactory function negatively correlates with age and high-density lipoprotein cholesterol.

CONCLUSION

Initial findings suggest that metabolic alterations are relevant for taste and smell function and TBD. By combining omics data from collected biomaterial with physiological, metabolic and psychological data related to taste perception and eating behaviour, the OTB study aims to strengthen our understanding of taste perception in obesity.

Correlations between Gustatory, Olfactory, Cognitive Function, and Age in Healthy Women

Aging is a progressive physiological degeneration associated with a decline in chemosensory processes and cognitive abilities and a reduction in synaptic plasticity. The biological bases of ageing are still not completely understood, and many theories have been proposed. This study aimed to evaluate the occurrence of age-related changes affecting the chemosensory function (gustatory and olfactory) and general cognitive abilities and their potential associations in women. To this aim, 319 women (the age ranging from 18 to 92 years) were recruited and divided into four different age groups: 18-34 years, 35-49 years, 50-64 years, and ≥65 years. Our results confirmed that in women, gustatory, olfactory, and cognitive functions decline, though in a different manner during aging. Olfactory and cognitive function showed a slight decline along the first three age classes, with a dramatic decrease after age 65 years, while gustatory function decreased more gradually. Olfactory and gustatory deficits may have a high degree of predictivity for general cognitive function as well as for specific cognitive subdomains such as visuospatial/executive abilities, language, memory, and attention. Our study highlighted the importance of using chemosensory assessments for the early diagnosis of cognitive decline and for the development of appropriate personalized risk prevention strategies.

Comparing a range of potassium-enriched low sodium salt substitutes to common salt: Results of taste and visual tests in South African adults

BACKGROUND AND AIMS

Potassium-enriched low sodium salt substitutes (LSSS), which replace a proportion of sodium chloride (NaCl) with potassium chloride (KCl), have been shown to reduce blood pressure and offer a potential solution to address the high burden of hypertension in South Africa. However, it is unknown which proportions of KCl in LSSS are acceptable. We compared the taste and visual acceptability of various LSSS in South African adults.

METHODS AND RESULTS

Fifty-six adults underwent double-blind taste and visual tests of four LSSS (35%KCl/65%NaCl; 50%KCl/50%NaCl; 66%KCl/34%NaCl; 100%KCl) in comparison to 100%NaCl (common salt). Participants scored each product by taste ranking, taste perception and likeliness to use. Participants then visually inspected the five products and attempted to identify which was which. Almost half (45 %) of participants ranked the taste of 50%KCl/50 %NaCl as fantastic or really good. Furthermore, 62 % of participants liked and would be happy to use the 50 %KCl/50 %NaCl or felt this tasted like common salt. Only 12 % rated the 100%KCl highly for taste, and over half reported being unlikely to use this. Most participants (57.3 % and 36.4 %) were able to visually identify 100%NaCl and 100%KCl, while identification of other blends was generally poor. Responses were similar for 35%KCl/65%NaCl and 66%KCl/34%NaCl throughout.

CONCLUSION

Our findings suggest that the taste of the 50%KCl salt substitute would be well tolerated by South African adults, most of which could not visually differentiate between this salt substitute and common salt.

Differences in time-intensity sensory profiles of sweet taste intensity of glucose between older and young adults

Background

To understand age-related changes in sweet taste perception in daily life, it is important to understand taste intensity at the suprathreshold level. Previous studies have attempted to characterize the temporal aspects of human taste perception in terms of time-intensity evaluations. The perception of dynamic taste intensity in older adults increases slowly for salty taste; however, there have been no previous studies on time-intensity sensory evaluation of sweet taste in older adults. We hypothesized that older adults perceive sweet taste intensity more slowly than young adults.

Methods

Fifty young and 40 older adults participated in the study and glucose solutions of 0.6 M and 1.5 M were used as stimuli. The study comprised two experiments: (1) a cup tasting test (static taste perception in the mouth), and (2) a time-intensity sensory evaluation, in which the solutions were presented using a custom-made delivery system. The intra-oral device was made to fit each participant's dentition. Further, the level of gag reflex was taken into consideration for each participant in the design of the intra-oral device. A suction tube was placed across the posterior tongue near the throat to remove solution and saliva. The solution delivery system was controlled by an original computer program.

Results

Older adults presented significantly different maximum intensity timing and slope for both concentrations compared with young adults (slope for 1.5 M, p < 0.01; others, p < 0.05). No significant differences were found between the older and young adults for reaction timing and maximum intensity.

Conclusion

We conclude that older adults perceived sweetness more slowly than young adults, and ultimately perceived almost the same intensity as young adults. This is the first reported characterization of the time-intensity profile of sweet taste intensity of glucose in older adults. Using a standardized system enabled us to assess and compare feedback on taste intensities among different age groups in real-time. Based on this, we recommend older adults "savor" to perceive sweet tastes at the same level experienced by young adults.

Genetic determinants of food preferences: a systematic review of observational studies

BACKGROUND

Over the last decade, the results of several studies have indicated that adults' food preferences, consumption, and dietary choices vary depending on their genotype characteristics. However, the results of studies related to genes and polymorphisms involved in this phenomenon are contradictory. This study is a systematic review designed to evaluate the genetic determinants of food preferences.

METHODS

This study was conducted following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Searches were conducted to identify articles testing the impact of genotypes on food choices, preferences, and intake in healthy adults. The search included all relevant keywords, and studies published between 1/1/1994 and October 2022 were considered. We assessed the quality of included studies and evaluated the risk of bias using the Newcastle-Ottawa Scale (NOS) for observational studies.

RESULTS

A total of 8,510 records were identified through our search method, and finally, 50 studies were included in this study. The majority of the studies evaluated the association of genetic variants with preferences for macronutrients, sweet, bitter, and fatty foods. The results of our study suggest a significant correlation between TAS2R38 variants (rs713598, rs1726866, rs10246939) and bitter and sweet taste preferences. Additionally, we found a considerable association between the T102C polymorphism of the 5-HT2A receptor gene and a higher intake of protein, and rs1761667 (CD36) was associated with fat preference.

CONCLUSION

In conclusion, this study revealed a significant association between certain genetic variants and food preferences among adults.

Histological and immunohistochemical studies of the fungiform and the circumvallate papillae through the life stages from 6- to 72-week-old Sprague-Dawley male rats

Taste sensitivity decreases with age. Therefore, we investigated the histological and immunohistochemical changes in the receptive fields circumvallate papilla (CvP) and fungiform papilla (FfP) to explore the mechanism underlying age-related changes in taste sensitivity in 6- to 72-week-old rats. We analyzed papilla size, the thickness of the keratin layer of the papilla and stratified squamous epithelium, taste bud size, the keratin layer around the taste pores in the CvP and FfP, and the number and distribution of taste buds in the CvP coronal section. We further assessed the expression of marker proteins for Type II and III cells, phospholipase C subtype beta 2 (PLCβ2), and synaptosomal-associated protein 25 (SNAP-25). The cellular activity of these taste cells was examined through co-localization with the senescence cell marker protein-30 (SMP30). There were no differences in the number of taste bud sections in the CvP among the age groups. However, the size of the CvP increased and the density of the taste bud area in the CvP area decreased with increasing age. In contrast, the number of cells with co-expression of SMP30, PLCβ2, and SNAP-25 decreased with age. Furthermore, the morphological structures of the CvP, FfP, and taste buds in these regions changed with age, but not the overall taste bud number in the CvP coronal section. The decrease in cell count with co-expression of SMP30 and PLCβ2, or SNAP-25 may indicate reduced cellular functions of taste cells with aging.

Quantitive Assessment of Gustatory Function and Its Association with Demographics, and Systemic Morbidity

This study aimed to analyze the associations of gustatory dysfunction as measured by validated taste strips with demographics and co-morbidities. This cross-sectional study retrospectively analyzed records of patients who attended the Orofacial Chemosensory Center of Hadassah Medical Center between 2017 and 2020. Taste strips were used as a validated method to determine taste dysfunction. A total of 272 subjects were included, 137 (50.4%) women and 135 (49.6%) men, with a mean age of 53.5 ± 19.3 years and age range of 18-98 years. The total taste score among the study population was 8.53 ± 4.03 (scale range 0-16). Age had a significant negative correlation with the total taste score (p = 0.001), and men exhibited worse total (p < 0.001), salty (p = 0.003), and bitter (p < 0.001) scores. Major trauma was associated with worse total (p < 0.001) and specialized taste assessments (sweet (p = 0.001), sour (p = 0.002), salty (p = 0.016), and bitter (p < 0.001)). Chemotherapy was associated with reduced total (p < 0.001), salty (p = 0.003), and bitter (p = 0.001) taste scores. Zinc deficiency exhibited worse salty (p = 0.027) and total (p = 0.038) taste scores. Patients with burning mouth syndrome (BMS) showed higher salty scores (p = 0.017). Patients who experienced exposure to toxic chemicals exhibited worse salty scores (p = 0.024). We conclude that gustatory dysfunction is associated with older age, male sex, and co-morbidities of major trauma, current chemotherapy, zinc deficiency, BMS, and exposure to toxins. The study highlights the importance of systemic evaluation and quantitive gustatory dysfunction assessment as part of the diagnostic process of patients with subjective complaints of taste disorders.

Lidocaine induces apoptosis in head and neck squamous cell carcinoma through activation of bitter taste receptor T2R14

Head and neck squamous cell carcinomas (HNSCCs) have high mortality and significant treatment-related morbidity. It is vital to discover effective, minimally invasive therapies that improve survival and quality of life. Bitter taste receptors (T2Rs) are expressed in HNSCCs, and T2R activation can induce apoptosis. Lidocaine is a local anesthetic that also activates bitter taste receptor 14 (T2R14). Lidocaine has some anti-cancer effects, but the mechanisms are unclear. Here, we find that lidocaine causes intracellular Ca2+ mobilization through activation of T2R14 in HNSCC cells. T2R14 activation with lidocaine depolarizes mitochondria, inhibits proliferation, and induces apoptosis. Concomitant with mitochondrial Ca2+ influx, ROS production causes T2R14-dependent accumulation of poly-ubiquitinated proteins, suggesting that proteasome inhibition contributes to T2R14-induced apoptosis. Lidocaine may have therapeutic potential in HNSCCs as a topical gel or intratumor injection. In addition, we find that HPV-associated (HPV+) HNSCCs are associated with increased TAS2R14 expression. Lidocaine treatment may benefit these patients, warranting future clinical studies.

The relationship between loneliness, psychological resilience, quality of life and taste change in cancer patients receiving chemotherapy

PURPOSE

This study aimed to determine the correlation between taste change, nutritional intake and quality of life in cancer patients receiving chemotherapy. A total of 610 (F = 314, M = 296) volunteers aged 19 and 65 who received outpatient chemotherapy treatment participated in the study.

METHODS

Individuals' general information was obtained, anthropometric measurements were carried out, malnutrition status (Patient-Generated Subjective Global Assessment PG-SGA), loneliness (Cancer Loneliness Scale), psychological resilience (Psychological Resilience Scale), quality of life (Quality of Life Scale (EORT QLQ-C30) and taste changes were scrutinized [Chemotherapy-Induced Taste Alteration Scale (CiTAS)].

RESULTS

There was a negative correlation between the Cancer Loneliness Scale and PG-SGA and General Health Status (r = -0.494, p = 0.000; r = -0.406, p = 0.000) and a positive correlation with Symptom Scales (r = 0.484, p = 0.000; r = 0.506, p = 0.000) (p < 0.05). There was a positive correlation between the Psychological Resilience Scale and General Health Status (r = 0.393, P = 0.000), Functional Scales (r = 0.349, P = 0.000), and a negative correlation between Symptom Scales (r = -0.302, p = 0.000) (p < 0.05). 70.9% of men and 70.7% of women had severe malnutrition. General Taste Changes, General Health and Symptom Scale values were significant predictors of severe malnutrition status (p < 0.05).

CONCLUSION

The symptoms that develop during the treatment process cause many psychological problems. Before starting treatment, patients should be evaluated comprehensively, depression anxiety levels and quality of life levels should be determined, and precautions should be taken accordingly.

Sodium intake trend and current intake level by meal provision place among the citizens of Seoul

BACKGROUND/OBJECTIVES

The diversity of meal provision places has increased in recent years and sodium intake can vary depending on where meals are eaten, particularly in large cities. In this study, an analysis of the recent trends in sodium intake was performed and a comparison of sodium intake level according to meal provision place among citizens of Seoul was performed.

SUBJECTS/METHODS

Data from a 24-h recall dietary intake survey from the 2010-2019 Korea National Health and Nutrition Examination Survey (KNHANES) were used in order to determine the trends in sodium intake among citizens of Seoul, aged 3-74 years old. (n = 11,811). The trend of daily sodium intake was presented in absolute amount and proportion compared to the chronic disease risk reduction intake (CDRR) for each selected characteristic. A comparison of sodium intake level according to meal provision place by sex and age groups as a total amount per meal (mg), density per meal (mg/1,000 kcal), and proportion of the daily sodium intake was performed using the 2016-2019 KNHANES.

RESULTS

Sodium intake levels showed a downward trend from 2010-2019. The highest level of sodium intake was observed for subjects aged 30-49, and the level for males aged 30-49 was 202.8% higher than the CDRR. Results of the analysis of sodium intake per meal according to meal provision place showed that the highest sodium intake was in the order of restaurant meal (RM) > institutional foodservice (IF) > home meal (HM) > convenience food (CF). A higher sodium density (mg/1,000 kcal) was observed for IF compared with RM in most adults. Adults aged over 50 years old consumed more than half of the daily sodium in HM.

CONCLUSION

Significant variation in the level of sodium intake was observed according to sex and age groups, therefore, different approaches and nutrition policies based on meal provision place are needed.

Sex Differences in the Bitterness Perception of an Aromatic Myrtle Bitter Liqueur and Bitter Compounds

We evaluated sex differences in the perception of bitter compounds and an aromatic bitter herbal liqueur (Mirtamaro) obtained by the infusion of myrtle leaves/berries together with a mixture of Mediterranean herbs/plants as flavoring/bittering ingredients. In a healthy population (n = 231 participants), using bivariate correlations and multivariate linear regression analyses, significant sex differences emerged in quinine bitterness perception, with women showing a higher bitter taste intensity rating than men. Among all participants, 40 subjects (subpopulation) were randomly selected for the evaluation of sex differences in Mirtamaro gustatory and olfactory perception using a hedonic Likert-type scale. Women showed higher ratings in Mirtamaro aroma (odor intensity) and bitterness (taste intensity) perception than men, with a superior capacity to perceive/describe its sensory attributes. 1,8-Cineole and methyl chavicol were the main contributors to the bitter liqueur aroma. A significant correlation (r = 0.564, p < 0.01) between Mirtamaro odor pleasantness/taste pleasantness was observed in women, indicating a positive contribution of aromatic herbs to bitter taste acceptability. Moreover, a higher bitter intensity rating of 6-n-propylthiouracil was evidenced in women than men. Our results highlighted sex differences in bitter taste acuity and the role of aromatic herbs/plants in modulating bitter taste acceptance, which is useful information in the field of precision nutrition and medicine.

Oral health-related quality of life after radiation therapy for head and neck cancer: the OraRad study

PURPOSE

Head and neck cancer (HNC) treatment results in morbidity impacting quality of life (QOL) in survivorship. This analysis evaluated changes in oral health-related QOL (OH-QOL) up to 2 years after curative intent radiation therapy (RT) for HNC patients and factors associated with these changes.

METHODS

572 HNC patients participated in a multicenter, prospective observational study (OraRad). Data collected included sociodemographic, tumor, and treatment variables. Ten single-item questions and 2 composite scales of swallowing problems and senses problems (taste and smell) from a standard QOL instrument were assessed before RT and at 6-month intervals after RT.

RESULTS

The most persistently impacted OH-QOL variables at 24 months included: dry mouth; sticky saliva, and senses problems. These measures were most elevated at the 6-month visit. Aspects of swallowing were most impacted by oropharyngeal tumor site, chemotherapy, and non-Hispanic ethnicity. Problems with senses and dry mouth were worse with older age. Dry mouth and sticky saliva increased more among men and those with oropharyngeal cancer, nodal involvement, and use of chemotherapy. Problems with mouth opening were increased by chemotherapy and were more common among non-White and Hispanic individuals. A 1000 cGy increase in RT dose was associated with a clinically meaningful change in difficulty swallowing solid food, dry mouth, sticky saliva, sense of taste, and senses problems.

CONCLUSIONS

Demographic, tumor, and treatment variables impacted OH-QOL for HNC patients up to 2 years after RT. Dry mouth is the most intense and sustained toxicity of RT that negatively impacts OH-QOL of HNC survivors.

CLINICALTRIALS

GOV IDENTIFIER

NCT02057510; first posted February 7, 2014.

Physiology of the tongue with emphasis on taste transduction

The tongue is a complex multifunctional organ that interacts and senses both interoceptively and exteroceptively. Although it is easily visible to almost all of us, it is relatively understudied and what is in the literature is often contradictory or is not comprehensively reported. The tongue is both a motor and a sensory organ: motor in that it is required for speech and mastication, and sensory in that it receives information to be relayed to the central nervous system pertaining to the safety and quality of the contents of the oral cavity. Additionally, the tongue and its taste apparatus form part of an innate immune surveillance system. For example, loss or alteration in taste perception can be an early indication of infection as became evident during the present global SARS-CoV-2 pandemic. Here, we particularly emphasize the latest updates in the mechanisms of taste perception, taste bud formation and adult taste bud renewal, and the presence and effects of hormones on taste perception, review the understudied lingual immune system with specific reference to SARS-CoV-2, discuss nascent work on tongue microbiome, as well as address the effect of systemic disease on tongue structure and function, especially in relation to taste.

Genetic variation in salt taste receptors impact salt intake and blood pressure

So far, few studies have examined the effect of salt taste receptors genetic variation on dietary intake in the Iranian population. We aimed to evaluate associations between single nucleotide polymorphisms (SNPs) in salt taste receptors' genes with dietary salt intake and blood pressure. A cross-sectional study was carried out among 116 randomly selected healthy adults aged ≥ 18 in Isfahan, Iran. Participants underwent sodium intake determination by 24-h urine collection, as well as dietary assessment by semi-quantitative food frequency questionnaire and blood pressure measurement. Whole blood was collected to extract DNA and genotype of SNP rs239345 in SCNN1B and rs224534, rs4790151 and rs8065080 in TRPV1 gene. Sodium consumption and diastolic blood pressure were significantly higher in carriers of the A-allele in rs239345 compared to subjects with the TT genotype (4808.4 ± 824.4 mg/day vs. 4043.5 ± 989.3 mg/day; P = 0.004) and 83.6 ± 8.5 mmHg vs. 77.3 ± 7.3 mmHg; P = 0.011), respectively. The level of sodium intake was lower in the TT genotype of TRPV1 (rs224534) than the CC genotype (3767.0 ± 713.7 mg/day vs. 4633.3 ± 793.5 mg/day; P = 0.012). We could not find any association between genotypes of all SNPs with systolic blood pressure as well as genotypes of rs224534, rs4790151 and rs8065080 with diastolic blood pressure. Genetic variations can relate with salt intake and consequently may associate with hypertension and finally cardiovascular disease risk in the Iranian population.

Bitter- and Umami-Related Genes are Differentially Associated with Food Group Intakes: the Framingham Heart Study

BACKGROUND

As suboptimal diet quality remains the leading modifiable contributor to chronic disease risk, it is important to better understand the individual-level drivers of food choices. Recently, a genetic component of food choices was proposed based on variants (SNPs) in genes related to taste perception (taste-related SNPs).

OBJECTIVES

This study aimed to determine the cumulative contribution of taste-related SNPs for basic tastes (bitter, sweet, umami, salt, and sour), summarized as "polygenic taste scores," to food group intakes among adults.

METHODS

Cross-sectional analyses were performed on 6230 Framingham Heart Study participants (mean age ± SD: 50 ± 14 y; 54% female). Polygenic taste scores were derived for tastes with ≥2 related SNPs identified in prior genome-wide association studies, and food group intakes (servings per week [sev/wk]) were tabulated from food frequency questionnaires. Associations were determined via linear mixed-effects models, using false discovery rates and bootstrap resampling to determine statistical significance.

RESULTS

Thirty-three taste-related SNPs (9 bitter, 19 sweet, 2 umami, 2 sour, 1 salt) were identified and used to derive polygenic taste scores for bitter, sweet, umami, and sour. Per additional allele for higher bitter perception, whole grain intakes were lower by 0.17 (95% CI: -0.28, -0.06) sev/wk, and for higher umami perception, total and red/orange vegetable intakes were lower by 0.73 (95% CI: -1.12, -0.34) and 0.25 (95% CI: -0.40, -0.10) sev/wk, respectively. Subsequent analyses at the SNP level identified four novel SNP-diet associations-two bitter-related SNPs with whole grains (rs10960174 and rs6782149) and one umami-related SNP with total and red/orange vegetables (rs7691456)-which may have been driving the identified associations.

CONCLUSIONS

Taste-related genes for bitter and umami were differentially associated with food choices that may impact diet quality. Hence, a benefit could be derived from leveraging knowledge of taste-related genes when developing personalized risk reduction dietary guidance.

Timing of Meals and Sleep in the Mediterranean Population: The Effect of Taste, Genetics, Environmental Determinants, and Interactions on Obesity Phenotypes

Circadian rhythms regulate the sleep-wake and feeding-fasting cycles. Sleep and feeding constitute a complex cycle that is determined by several factors. Despite the importance of sleep duration and mealtimes for many obesity phenotypes, most studies on dietary patterns have not investigated the contribution of these variables to the phenotypes analyzed. Likewise, they have not investigated the factors related to sleep or mealtimes. Thus, our aims were to investigate the link between taste perception and eating/sleep patterns and to analyze the effect of the interactions between sleep/meal patterns and genetic factors on obesity phenotypes. We conducted a cross-sectional analysis on 412 adults from the Mediterranean population. We measured taste perception (bitter, sweet, salty, sour, and umami) and assessed sleep duration and waketime. The midpoint of sleep and social jetlag was computed. From the self-reported timing of meals, we estimated the eating window, eating midpoint, and eating jetlag. Adherence to the Mediterranean diet was measured with a validated score. Selected polymorphisms in the TAS2R38, CLOCK, and FTO genes were determined, and their associations and interactions with relevant phenotypes were analyzed. We found various associations between temporal eating, sleep patterns, and taste perception. A higher bitter taste perception was associated with an earlier eating midpoint (p = 0.001), breakfast time (p = 0.043), dinner time (p = 0.009), waketime (p < 0.001), and midpoint of sleep (p = 0.009). Similar results were observed for the bitter taste polymorphism TAS2R38-rs713598, a genetic instrumental variable for bitter perception, increasing the causality of the associations. Moreover, significant gene-sleep interactions were detected between the midpoint of sleep and the TAS2R38-rs713598 (p = 0.032), FTO-rs9939609 (p = 0.037), and CLOCK-rs4580704 (p = 0.004) polymorphisms which played a role in determining obesity phenotypes. In conclusion, our study provided more information on the sleep and mealtime patterns of the general Spanish Mediterranean population than on their main relationships. Moreover, we were able to show significant associations between taste perception, specifically bitter taste; sleep time; and mealtimes as well as an interaction between sleep time and several genetic variants linked to obesity phenotypes. However, additional research is needed to better characterize the causality and mechanisms behind these associations.

[The application of waterless empirical taste test（WETT®） in 159 Chinese healthy subjects]

Objective:This study examined the influences of age and gender on the taste function of a sizable sample of healthy Chinese subjects using the Waterless Empirical Taste Test（WETT®）, and provided scientific evidences for taste evaluation in clinic. Methods:A total of 159 subjects were tested based on strict inclusion and exclusion criteria. The 53 stimuli strips, presented on monomer cellulose pads, were designed to test 5 basic taste functions including sour, sweet, bitter, salty and umami of all subjects. The analysis was computed in SAS 9.4 statistical software. Results:The total taste score of the subjects was 35.00±8.94; the average test administration time was（21.61±7.80） min. The total test scores decreased across age categories（young group: 37.41±8.12, middle-aged group: 34.48±9.04, elderly group: 29.31±8.64）, the correlation coefficient between the total test scores and age was r=-0.335, P<0.05. There were significant differences in sour and bitter scores among different age groups（Psour=0.019, Pbitter<0.001）. Overall, women outperformed men on the total test（[36.53±8.72]vs[32.93±8.87], P=0.012）. There were correlations among individual taste of scores, and the correlation coefficient between umami and total score was the strongest（rumami/total=0.700，P<0.05）. Conclusion:This study demonstrated that a simple self-administered taste test, the WETT®, could be applied to Chinese healthy people. Age and gender-effects are the main factors which affect gustatory function.

Impact of Calorie-Restricted Cafeteria Diet and Treadmill Exercise on Sweet Taste in Diet-Induced Obese Female and Male Rats

The goal of the present study was to evaluate the sweet taste function in obese rats fed with a 30% calorie-restricted cafeteria diet (CAFR) and/or subjected to moderate treadmill exercise (12-17 m/min, 35 min, 5 days per week) for 9 weeks. A two-bottle preference test, a taste reactivity test, and a brief-access licking test were carried out when animals were aged 21 weeks; biometric and metabolic parameters were also measured along the interventions. Two separate experiments for females and males were performed. Behaviorally, CAF diet decreased sucrose intake and preference, as well as perceived palatability, in both sexes and decreased hedonic responses in males. Compared to the CAF diet, CAFR exerted a corrective effect on sweet taste variables in females by increasing sucrose intake in the preference test and licking responses, while exercise decreased sucrose intake in both sexes and licking responses in females. As expected, CAF diet increased body weight and Lee index and worsened the metabolic profile in both sexes, whereas CAFR diet ameliorated these effects mainly in females. Exercise had no noticeable effects on these parameters. We conclude that CAF diet might diminish appetitive behavior toward sucrose in both sexes, and that this effect could be partially reverted by CAFR diet in females only, while exercise might exert protective effects against overconsumption of sucrose in both sexes.

The Influence of Nutritional Status and Sleep Quality on Gustatory Function in Older Adults

Background and Objectives: Age-related declines in taste function are common. Taste acuity can be affected by nutritional status and sleep quality. This research aims to examine the effect of nutritional status and sleep quality on gustatory function in community-dwelling older adults. Materials and Methods: This cross-sectional study included 119 community-dwelling older adults (50.4% of whom were female). The gustatory function was evaluated using four liquid taste solutions (sweet, bitter, sour, and salty) each at four different concentrations and the Mini Nutritional Assessment (MNA) and Pittsburgh Sleep Quality Index (PSQI) was applied. Additionally, anthropometric measurements were taken. Results: The mean scores on the gustatory test for the sweet, bitter, sour, and salty tastes were 2.11 ± 1.27, 2.12 ± 1.03, 2.28 ± 1.03, and 1.98 ± 1.41, respectively. There were significant differences according to gender, polypharmacy, nutritional status, and sleep quality in identifying sweet tastes (all p < 0.05). It was also found that females and participants without polypharmacy had better scores for bitter tastes. When the gustatory functions were evaluated according to BMI classification, it was determined that underweight participants had a higher sour taste score than the obese ones. Multiple regression analysis revealed that age, MNA score, PSQI score, and gender accounted for a total of 20.4% of the variance in the sweet taste score. Conclusions: Determining the relationship between taste function, nutritional status, and sleep quality in older adults is important in terms of developing new strategies for older adults who have these problems.

Research gaps and opportunities in precision nutrition: an NIH workshop report

Precision nutrition is an emerging concept that aims to develop nutrition recommendations tailored to different people's circumstances and biological characteristics. Responses to dietary change and the resulting health outcomes from consuming different diets may vary significantly between people based on interactions between their genetic backgrounds, physiology, microbiome, underlying health status, behaviors, social influences, and environmental exposures. On 11-12 January 2021, the National Institutes of Health convened a workshop entitled "Precision Nutrition: Research Gaps and Opportunities" to bring together experts to discuss the issues involved in better understanding and addressing precision nutrition. The workshop proceeded in 3 parts: part I covered many aspects of genetics and physiology that mediate the links between nutrient intake and health conditions such as cardiovascular disease, Alzheimer disease, and cancer; part II reviewed potential contributors to interindividual variability in dietary exposures and responses such as baseline nutritional status, circadian rhythm/sleep, environmental exposures, sensory properties of food, stress, inflammation, and the social determinants of health; part III presented the need for systems approaches, with new methods and technologies that can facilitate the study and implementation of precision nutrition, and workforce development needed to create a new generation of researchers. The workshop concluded that much research will be needed before more precise nutrition recommendations can be achieved. This includes better understanding and accounting for variables such as age, sex, ethnicity, medical history, genetics, and social and environmental factors. The advent of new methods and technologies and the availability of considerably more data bring tremendous opportunity. However, the field must proceed with appropriate levels of caution and make sure the factors listed above are all considered, and systems approaches and methods are incorporated. It will be important to develop and train an expanded workforce with the goal of reducing health disparities and improving precision nutritional advice for all Americans.

A Cross-Sectional Analysis of Food Perceptions, Food Preferences, Diet Quality, and Health in a Food Desert Campus

The sensory properties of foods guide food choices and intake, importantly determining nutritional and health status. In communities that have inconsistent access to nutritious foods, such as food deserts, food taste perceptions and preferences have yet to be explored. The purpose of this study was to examine how taster status (supertaster vs. non-taster) and food security status (high or marginal vs. low or very low) influences food taste intensities, food preferences and perceptions, and diet quality in a cohort of students from a food desert campus in the Central Valley of California. Moreover, the complex relationship of socioeconomic status, race/ethnicity, and sex on cardiometabolic and cognitive health warrants further examination. Two hundred fifty participants (aged 18-24 years) living in a food desert campus were recruited in 2018 for this cross-sectional study where participants underwent taste tests on selected fruits, vegetables, and nuts, and clinical tests (anthropometrics, blood glucose, blood pressure, and endothelial function), cognitive function tests (memory and attention), diet quality assessment (Healthy Eating Index (HEI)), and food preference and perception assessments. Food taste intensities were influenced by sex with bitter and umami taste intensities of several foods being perceived more intensely by males. Moreover, food liking was largely influenced by ethnicity with Hispanics having higher liking ratings for several foods compared with non-Hispanics. Both, Hispanics and females, had higher total fruit HEI scores and lower attention scores than non-Hispanics and males, respectively. Females also had lower blood pressure, reactive hyperemia index, and fasting blood glucose. Food-insecure individuals rated cost and convenience as more important factors for overall food consumption and had lower attention scores than those with higher food-security status. Future research should consider the complex interactions of factors such as taste and flavor perception, sex, ethnicity, prior exposure to foods, and other environmental factors when studying food preferences and health in young adults.

Genetic variation in sweet taste receptors and a mechanistic perspective on sweet and fat taste sensation in the context of obesity

Taste sensation enables humans to make nutritionally important decisions such as food preference and consumption. It functions as deterministic factors for unpropitious eating behavior, leading to overweight and obesity. The hedonistic feeling on consumption of fat and sugar-rich meals, in particular, has a negative influence on health. In addition, impairment in the taste receptors alters the downstream signaling of taste transduction pathway. Hence, genetic polymorphism in typical taste receptors is a predictor of taste sensitivity variance across individuals. The present review summarizes the effect of a single nucleotide polymorphism (SNP) in sweet taste receptors (T1R2/T1R3) on taste perception among individuals of various body mass index (BMI). Furthermore, in the context of obesity, we discussed the possibility of crosstalk between fat and sweet receptors as well as taste dysfunction in diseased individuals. In overall, a greater understanding of the physiological relationship between taste receptors, altered taste sensitivity, and genetic polymorphisms should lead to more effective obesity prevention approaches.

Associations between Sweet Taste Sensitivity and Polymorphisms (SNPs) in the TAS1R2 and TAS1R3 Genes, Gender, PROP Taster Status, and Density of Fungiform Papillae in a Genetically Homogeneous Sardinian Cohort

Individual differences in sweet taste sensitivity can affect dietary preferences as well as nutritional status. Despite the lack of consensus, it is believed that sweet taste is impacted by genetic and environmental variables. Here we determined the effect of well-established factors influencing the general taste variability, such as gender and fungiform papillae density, specific genetic variants (SNPs of TAS1R2 and TAS1R3 receptors genes), and non-specific genetic factors (PROP phenotype and genotype), on the threshold and suprathreshold sweet taste sensitivity. Suprathreshold measurements showed that the sweet taste response increased in a dose-dependent manner, and this was related to PROP phenotype, gender, rs35874116 SNP in the TAS1R2 gene, and rs307355 SNP in the TAS1R3 gene. The threshold values and density of fungiform papillae exhibited a strong correlation, and both varied according to PROP phenotype. Our data confirm the role of PROP taste status in the sweet perception related to fungiform papilla density, show a higher sweet sensitivity in females who had lower BMI than males, and demonstrate for the first time the involvement of the rs35874116 SNP of TAS1R2 in the sweet taste sensitivity of normal weight subjects with body mass index (BMI) ranging from 20.2 to 24.8 kg/m2. These results may have an important impact on nutrition and health mostly in subjects with low taste ability for sweets and thus with high vulnerability to developing obesity or metabolic disease.

Comparison of Bitterness Intensity between Prednisolone and Quinine in a Human Sensory Test Indicated Individual Differences in Bitter-Taste Perception

Prednisolone is a frequently prescribed steroid with a bitter, unpalatable taste that can result in treatment refusal. Oral suspensions or powder dosage forms are often prescribed, particularly to pediatric patients, as they improve swallowability and ease of dose adjustment. Consequently, the bitterness of prednisolone is more apparent in these dosage forms. Few studies have investigated prednisolone's bitterness. Thus, in this study, 50 adults evaluated the bitterness of prednisolone using the generalized Labeled Magnitude Scale (gLMS), in comparison with quinine, a standard bitter substance. Overall, prednisolone-saturated solution demonstrated the same extent (mean gLMS score: 46.8) of bitterness as 1 mM quinine solution (mean gLMS score: 40.1). Additionally, large individual differences were observed in the perception of the bitterness of prednisolone and quinine. Perceived flavors of some drugs are reportedly associated with bitter-taste receptor (TAS2Rs) polymorphisms. Therefore, we investigated the relationship between subjects' genetic polymorphisms of TAS2R19, 38, and 46, and their sensitivity to bitterness. Although a relationship between TAS2R19 polymorphisms and the perception of quinine bitterness was observed, no significant relationship was found between the perceived bitterness of prednisolone and the investigated genes. Ultimately, the results show that despite individual differences among subjects, the cause of prednisolone's strong bitterness is yet to be elucidated.

Opportunities and barriers for food intake in older age - a Norwegian perspective

Background

The ageing processes occur slowly over time and are often not detectable by the individual. Thus, preparing for dietary needs in later years should start at an earlier age than most people realise.

Objective

This study aims at better understanding what characterises food-related practices in active, home-living older adults, in order to identify food-related factors that act as barriers and those that promote healthy ageing.

Design

Three experiments were conducted: First, a web-based quantitative survey to collect information about home-living older adults' food-related behaviours (67+ years, N = 1,005). Second, two focus groups with respondents 67-74 years (N = 7) and 75-84 years (N = 6) to elicit aspects not adequately covered in the survey. Third, 10 individual interviews to provide in-depth insights.

Results

Two distinct groups were identified in the survey; 67-79 years and 80+ years. The older age group experienced more barriers and restrictions in food intake and food-related behaviours compared to the younger group. Good taste, routines and social settings were important for appetite and food intake.

Discussion

Using a mixed-methods approach proved valuable for extracting information and a better understanding of what impacts on food-related aspects amongst older adults. Strategies for upholding a healthy food intake involve establishing daily routines and meeting arenas where older adults can socialise and eat food together.

Conclusion

This study confirmed that knowledge of older adults' physical needs, barriers and abilities must be a part in preparation for a healthy diet.

Umami detection threshold among children of different ethnicities and its correlation with various indices of obesity and blood pressure

Sensitivity to savory taste has been linked to high consumption of savory foods and increased risks of obesity and hypertension. However, there are limited studies that investigate whether obesity indices are correlated with the differences in umami taste perception, particularly in children. This study aimed to investigate the umami detection threshold among children of different ethnicities and the threshold's correlation with obesity indices and blood pressure. A total of 140 subjects were recruited and consisted of a nearly equal distribution of children from three main ethnicities (37.2% Malays, 31.4% Chinese, 31.4% Indians). Umami detection threshold was measured using the two-alternative, forced-choice staircase procedure. Body weight, height, waist circumference and blood pressure of children were measured. Body composition was assessed using bioelectrical impedance analysis (BIA). Mean umami detection threshold was 1.22 ± 1.04 mM and there were no observable differences attributable to the subjects' ethnicities. Body fat percentage was negatively correlated (r = −0.171, p < 0.05), while lean body mass percentage was positively correlated (r = 0.171, p < 0.05) with umami detection threshold. These findings revealed that umami taste perception correlated with children's body composition, but not other anthropometric indicators and blood pressure. Future studies should explore the correlation between umami taste perception and children's total dietary intake.

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The average umami detection threshold of Malaysian children was 1.22 ± 1.04 mM.

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No gender or ethnic differences in umami detection thresholds were observed.

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Umami taste perception was correlated only with children's body composition.

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It is worth to consider umami taste threshold in designing low-sodium food products.