Differences In Taste Perception Research Articles

Crosslinguistic Differences in Food Labels Do Not Yield Differences in Taste Perception

AbstractResearch has shown that speakers of different languages may differ in their cognitive and perceptual processing of reality. A common denominator of this line of investigation has been its reliance on the sensory domain of vision. The aim of our study was to extend the scope to a new sense—taste. Using as a starting point crosslinguistic differences in the category boundaries of edible bulbs, we examined whether monolingual speakers of English and bilingual speakers of Norwegian and English were influenced by language‐specific categories during tasting. The results showed no evidence of such effects, not even for the Norwegian participants in an entirely Norwegian context. This suggests that crosslinguistic differences in visual perception do not readily generalize to the domain of taste. We discuss the findings in terms of predictive processing, with particular reference to trigeminal stimulation (a central tasting component) and the interplay between chemosensory signals and top‐down linguistic modulation.

Is sugar as sweet to the palate as seeds are appetizing to the belly? Taste responsiveness to five food-associated carbohydrates in zoo-housed white-faced sakis, Pithecia pithecia.

Differences in taste perception between species are thought to reflect evolutionary adaptations to dietary specialization. White-faced sakis (Pithecia pithecia) are commonly considered as frugivores but are unusual among primates as they do not serve as seed dispersers but rather prey upon the seeds of the fruits they consume and are thought to exploit the lipids and proteins that these seeds contain in high amounts. Using a two-bottle preference test of short duration we therefore assessed whether this dietary specialization affects the taste responsiveness of four adult white-faced sakis for five food-associated carbohydrates. We found that the sakis significantly preferred concentrations as low as 10 mM sucrose, 10-40 mM fructose, 20-30 mM glucose and maltose, and 30-40 mM lactose over tap water. When given the choice between all binary combinations of these five saccharides presented at equimolar concentrations of 100, 200, and 300 mM, respectively, the sakis displayed significant preferences for individual saccharides in the following order: sucrose > fructose > glucose ≥ maltose = lactose. These results demonstrate that seed-predating white-faced sakis have a well-developed taste sensitivity for food-associated carbohydrates which is not inferior to that of most other primates including seed-dispersing frugivores, but rather ranks among the more sweet-taste sensitive species. Further, they show that their pattern of relative preference for the five carbohydrates is similar to that found in other frugivorous primate species. These findings may represent an example of Liem's paradox as the sakis' morphological adaptations to efficiently predate on and exploit the lipid- and protein-rich hard-shelled seeds of fruits does not compromise their ability to detect the carbohydrates found in the pulp of fruits at low concentrations.

Brain activation in individuals suffering from bulimia nervosa and control subjects during sweet and sour taste stimuli.

Episodes of eating great quantities of extremely sweet and often aversive tasting food are a hallmark of bulimia nervosa. This unique eating pattern led researchers to seek and find differences in taste perception between patients and healthy control subjects. However, it is currently not known if these originate from central or peripheral impairment in the taste perception system. In this cross sectional study, we compare brain response to sweet and sour stimuli in 5 bulimic and 8 healthy women using functional magnetic resonance imaging (fMRI). Sweet, sour and neutral (colorless and odorless) taste solutions were presented to subjects while undergoing fMRI scanning. Data were analyzed using a block design paradigm. Between-group differences in brain activation in response to both sweet and sour tastes were found in 11 brain regions, including operculum, anterior cingulate cortex, midbrain, and cerebellum. These are all considered central to perception and processing of taste. Our data propose that sweet and sour tastes may have reward or aversion eliciting attributes in patients suffering from bulimia nervosa not found in healthy subjects, suggesting that alteration in taste processing may be a core dysfunction in bulimia nervosa (BN).

Comparison of sensitivity to taste and astringency stimuli among vegans and omnivores

Taste perception plays a crucial role in determining food choices. It has been described in literature a relationship between diet composition and taste perception. Nowadays, with the rising concern in climate change and animal welfare, the number of people following a vegan diet is increasing to become a real trend. Research about differences in taste perception between vegan and omnivore is lacking. The aim of the study was to compare detection threshold for bitter, sour, umami and astringency stimuli (quinine monohydrochloride dihydrate, citric acid anhydrous, monosodium glutamate and tannic acid, respectively) participants following a vegan diet (n=24) and participants following an omnivore diet (n=30). Participants reported their consumption frequency for main food categories. The mean detection thresholds between the two groups narrowly missed significance with p-values of 0.07, 0.08, 0.06, for bitter, umami and astringency perception, respectively. No differences were found for sour taste (p-value=0.33). Further research is required to validate such findings and to understand the origin of the relationship between diet style and taste sensitivity.

Sensory Measurements of Taste: Aiming to Visualize Sensory Differences in Taste Perception by Consumers—An Experiential fNIRS Approach

Especially for long-term acceptance, taste is the most important determinant to assess consumer habitual uptake of food products. Monitoring neuronal processes is expected to provide insights for hedonic preferences. The aims of this study are: (1) to find out whether and how two different taste nuances are reflected in the neuronal data and (2) to assess whether preference of two plant-based milk alternatives can be detected. In total 91 subjects underwent a tasting experiment with two different plant-based milks (oat and almond milk) and a water sample (neutral taste), while neuronal data was recorded. A relative decrease in oxygenated hemoglobin (oxyHb) during tasting was detected in parts of the dorsolateral prefrontal cortex (dlPFC). However, no differences were detected between the three samples, although the overall liking on hedonic scales differed. Hence, the assessment may have visualized the taste process activation, but could not assign a differentiated hedonic preference evaluation. For the latter a stronger polarity may be needed.

TAS1R3 and TAS2R38 Polymorphisms Affect Sweet Taste Perception: An Observational Study on Healthy and Obese Subjects.

Background: The inter-individual differences in taste perception find a possible rationale in genetic variations. We verified whether the presence of four different single nucleotide polymorphisms (SNPs) in genes encoding for bitter (TAS2R38; 145G > C; 785T > C) and sweet (TAS1R3; −1572C > T; −1266C > T) taste receptors influenced the recognition of the basic tastes. Furthermore, we tested if the allelic distribution of such SNPs varied according to BMI and whether the associations between SNPs and taste recognition were influenced by the presence of overweight/obesity. Methods: DNA of 85 overweight/obese patients and 57 normal weight volunteers was used to investigate the SNPs. For the taste test, filter paper strips were applied. Each of the basic tastes (sweet, sour, salty, bitter) plus pure rapeseed oil, and water were tested. Results: Individuals carrying the AV/AV diplotype of the TAS2R38 gene (A49P G/G and V262 T/T) were less sensitive to sweet taste recognition. These alterations remained significant after adjustment for gender and BMI. Moreover, a significant decrease in overall taste recognition associated with BMI and age was found. There was no significant difference in allelic distribution for the investigated polymorphisms between normal and overweight/obese patients. Conclusions: Our findings suggest that overall taste recognition depends on age and BMI. In the total population, the inter-individual ability to identify the sweet taste at different concentrations was related to the presence of at least one genetic variant for the bitter receptor gene but not to the BMI.

Comparison of Chinese and American subjects on the self-administered Waterless Empirical Taste Test.

Cultural differences have been reported between the taste sensitivity of persons of Asian and European ancestry, although findings have been mixed. This study sought to determine whether American and Chinese adults perform differently on a novel taste test that requires no water, can be self‐administered, and employs a representative of umami as one of its tastants. This 53‐trial test was administered to 113 Chinese and 214 Americans. The subjects orally sampled monomer cellulose pads containing one of four dried concentrations of sucrose, citric acid, NaCl, caffeine, and monosodium glutamate and indicated whether a sweet, sour, bitter, salty, brothy, or no taste sensation was perceived. Separate gender by culture analyses of covariance with age as the covariate were performed on the total score and the scores of each taste stimulus. For all taste qualities, women outperformed men and test scores declined with age. No difference between American and Chinese subjects was found for the total taste score (p = .129) or for the sucrose (p = .129) or NaCl (p = .368) scores. However, for monosodium glutamate, the scores were 28.40% higher for the Chinese than for the American subjects (p = .024), and for citric acid and caffeine, the scores were 24.12 and 21.79% higher for the American subjects (p's = .001 and .029). The basis for these differences is unclear, although both anatomical (e.g., differences in density or distribution of taste buds) and cultural factors may be involved. Future work is needed to determine the cause of these largely novel findings and whether they generalize to other Chinese and American samples. Practical applicationsIn this study, a practical self‐administered quantitative taste test that requires no water was found to be sensitive to quality‐specific differences in test scores between Chinese and American subjects, as well as to age and gender. The Chinese subjects outperformed the American subjects in correctly identifying the quality of monosodium glutamate (umami), whereas the American subjects outperformed Chinese subjects in correctly identifying the bitter and sour qualities of caffeine and citric acid, respectively. Experiential factors related to culture‐specific cuisines may explain some of these differences. This research indicates that a relatively rapid taste test, which can be sent through the mail and which requires no test administrator or source of water, can be used in cross‐cultural studies to elucidate individual differences in taste perception.

Taste perception and expression in stomach of bitter taste receptor tas2r38 in obese and lean subjects

Differences in taste perception have been related to eating behavior, nutritional status, and diseases. Recently, taste receptors have been identified in several extra-oral tissues, such as the gastrointestinal tract, where they seem to influence processes like digestion, sense of satiety as well as energy balance and intraluminal changes occurring in obesity.Our study aims to analyze differences in taste perception among 42 obese patients (OB) and 41 normal-weight subjects (LEAN). Polymorphisms in the gene codifying for the bitter taste receptor TAS2R38 and its expression on the surface of the gastric mucosa were tested and compared among OB and LEAN.Taste intensity of PROP (6-n-propylthiouracil), quinine, sucrose, citric acid and NaCl were measured on a labeled magnitude scale. DNA from peripheral whole blood was extracted and three polymorphisms in the TAS2R38 gene (rs713598, rs1726866, rs10246939) analyzed. Gastric biopsies were collected during bariatric surgery in OB and during endoscopy in LEAN. RNA was extracted and TAS2R38 gene expression assessed by RT-Real-Time qPCR. Anamnestic and anthropometric data were recorded in all participants during baseline visits.Logistic regression analysis showed that OB perceives sweet (sucrose) and bitter (PROP or 6-n-propylthiouracil) taste more intensely than LEAN (p-value = 0.02 and p-value = 0.005, respectively). While polymorphisms in TAS2R38 gene did not differ among OB and LEAN, we observed a significant increase of TAS2R38 mRNA levels in the stomach of OB compared to LEAN (p = 0.01).Our results provide new evidence of a link between obesity and altered taste perception as well as TAS2R38 expression in the stomach.

Psychophysical Tracking Method to Assess Taste Detection Thresholds in Children, Adolescents, and Adults: The Taste Detection Threshold (TDT) Test

This paper describes a two-alternative, forced-choice, staircase, tracking procedure, called the Taste Detection Threshold (TDT) test, that provides a reliable measure of sweet, salty, and umami taste detection thresholds from childhood to adulthood. Advantages of the method include procedures that are identical for children and adults, thus allowing the determination of age-related and individual differences in taste perception, if any, and tasks that can be completed in a relatively short time frame, do not rely on continuous attention or require memorization, control for subjective response biases, and minimize the impact of language development. After a 1 hour fast, participants are presented with pairs of solutions; in each pair, one solution is water, and the other solution contains varying concentrations of the tastant. Using a whole-mouth tasting method, participants taste each solution (without swallowing and with rinsing between tastings) and then point to the solution with a taste or that tastes different from water. The concentration of the stimulus in the subsequent pair increases after a single incorrect response and decreases after two consecutive correct responses. A reversal occurs when the concentration sequence changes direction. The task is deemed completed after the occurrence of four reversals, provided there are a maximum of two dilution steps between two successive reversals, and the series of reversals do not form an ascending pattern. These additional criteria ensure greater reliability in outcomes. The TDT is then calculated as the geometric mean of the concentrations of the four reversals. This method has real-world relevance as it provides information on a dimension of taste perception that is independent of hedonics, and that can change with aging and certain disease states, making it a valuable psychophysical test.

Psychophysical Tracking Method to Assess Taste Detection Thresholds in Children, Adolescents, and Adults: The Taste Detection Threshold (TDT) Test

This paper describes a two-alternative, forced-choice, staircase, tracking procedure, called the Taste Detection Threshold (TDT) test, that provides a reliable measure of sweet, salty, and umami taste detection thresholds from childhood to adulthood. Advantages of the method include procedures that are identical for children and adults, thus allowing the determination of age-related and individual differences in taste perception, if any, and tasks that can be completed in a relatively short time frame, do not rely on continuous attention or require memorization, control for subjective response biases, and minimize the impact of language development. After a 1 hour fast, participants are presented with pairs of solutions; in each pair, one solution is water, and the other solution contains varying concentrations of the tastant. Using a whole-mouth tasting method, participants taste each solution (without swallowing and with rinsing between tastings) and then point to the solution with a taste or that tastes different from water. The concentration of the stimulus in the subsequent pair increases after a single incorrect response and decreases after two consecutive correct responses. A reversal occurs when the concentration sequence changes direction. The task is deemed completed after the occurrence of four reversals, provided there are a maximum of two dilution steps between two successive reversals, and the series of reversals do not form an ascending pattern. These additional criteria ensure greater reliability in outcomes. The TDT is then calculated as the geometric mean of the concentrations of the four reversals. This method has real-world relevance as it provides information on a dimension of taste perception that is independent of hedonics, and that can change with aging and certain disease states, making it a valuable psychophysical test.

The role of sour and bitter perception in liking, familiarity and choice for phenol-rich plant-based foods

Among factors influencing food preferences and choices, individual differences in taste perception play a key role in defining eating behaviour. In particular, sour and bitter responsiveness could be associated with the acceptance and the consumption of phenol-rich plant-based foods recommended for a healthy diet. The aim of this study was to investigate, in a large population sample, the associations among sour and bitter responsiveness and liking, familiarity and choice for plant-based foods characterized by these target tastes. Adults aged 18 to 60 years (n = 1198; 58% women) were tested for their sour and bitter responsiveness both in water solutions and in food models (pear juice-based beverages modified in citric acid content to induce different levels of sourness: 0.5, 2.0, 4.0 and 8.0 g/kg; chocolate pudding samples modified in sucrose content to induce different levels of bitterness: 38, 83, 119, 233 g/kg). Familiarity, stated liking and choice for fruit juices and vegetables varying for sour/bitter taste (high in bitter/sour taste: e.g. grapefruit juice and cauliflower; low in bitter/sour taste: e.g. zucchini and pineapple juice) were measured. Results showed a significant positive correlation between bitter and sour taste perception in water solutions and model foods, as well as a positive correlation between the perceived intensity of the two taste stimuli. Subjects characterized by high responsiveness to the two target stimuli were found to give lower liking scores to foods characterized by sour/bitter tastes and tended to choose less sour/bitter foods compared to less responsive subjects.Thus, food choice for phenol rich plant-based products could be associated with a reduced responsiveness to bitter and sour tastes and a consequent higher acceptance of food products characterized by these taste qualities.

Taste Interactions between Sweetness of Sucrose and Sourness of Citric and Tartaric Acid among Chinese and Danish Consumers.

Tastes interact in almost every consumed food or beverage, yet many aspects of interactions, such as sweet-sour interactions, are not well understood. This study investigated the interaction between sweetness from sucrose and sourness from citric and tartaric acid, respectively. A cross-cultural consumer study was conducted in China (n = 120) and Denmark (n = 139), respectively. Participants evaluated six aqueous samples with no addition (control), sucrose, citric acid, tartaric acid, or a mixture of sucrose and citric acid or sucrose and tartaric acid. No significant difference was found between citric acid and tartaric acid in the suppression of sweetness intensity ratings of sucrose. Further, sucrose suppressed sourness intensity ratings of citric acid and tartaric acid similarly. Culture did not impact the suppression of sweetness intensity ratings of citric or tartaric acid, whereas it did influence sourness intensity ratings. While the Danish consumers showed similar suppression of sourness by both acids, the Chinese consumers were more susceptible towards the sourness suppression caused by sucrose in the tartaric acid-sucrose mixture compared to the citric acid-sucrose mixture. Agglomerative hierarchical cluster analysis revealed clusters of consumers with significant differences in sweetness intensity ratings and sourness intensity ratings. These results indicate that individual differences in taste perception might affect perception of sweet-sour taste interactions, at least in aqueous solutions.

TAS2R38 bitter taste receptor and attainment of exceptional longevity

Bitter taste receptors play crucial roles in detecting bitter compounds not only in the oral cavity, but also in extraoral tissues where they are involved in a variety of non‒tasting physiological processes. On the other hand, disorders or modifications in the sensitivity or expression of these extraoral receptors can affect physiological functions. Here we evaluated the role of the bitter receptor TAS2R38 in attainment of longevity, since it has been widely associated with individual differences in taste perception, food preferences, diet, nutrition, immune responses and pathophysiological mechanisms. Differences in genotype distribution and haplotype frequency at the TAS2R38 gene between a cohort of centenarian and near-centenarian subjects and two control cohorts were determined. Results show in the centenarian cohort an increased frequency of subjects carrying the homozygous genotype for the functional variant of TAS2R38 (PAV/PAV) and a decreased frequency of those having homozygous genotype for the non-functional form (AVI/AVI), as compared to those determined in the two control cohorts. In conclusion, our data providing evidence of an association between genetic variants of TAS2R38 gene and human longevity, suggest that TAS2R38 bitter receptor can be involved in the molecular physiological mechanisms implied in the biological process of aging.

EphB2 receptor forward signaling is needed for normal long-term memory formation in aged mice

The molecular mechanisms underpinning age-related changes in the ability to form long-term memory need to be clarified. EphB2 receptors and their ephrin ligands are involved in key cellular functions such as neuronal morphogenesis and synaptic transmission believed to be involved in long-term memory formation. We were therefore interested to explore whether EphB2 is involved in the alterations in memory formation abilities observed in old age. Toward that end, we examined the ability to form long-term memory in mice that lack EphB2 (EphB2-/-). A previous study has shown that the ability to form long-term conditioned taste aversion (CTA) memory in young EphB2-/- mice remains intact. In the present study, we report that long-term CTA memory formation is improved in old wild-type mice but not in age-matched old EphB2-/- mice. To further explore EphB2 mechanisms responsible for this difference in memory formation ability, we examined CTA memory in EphB2lacZ/lacZ mice devoid of EphB2 forward signaling. We found that the ability to create CTA long-term memory is unaffected in young EphB2lacZ/lacZ mice. However, the ability to form an increased long-term CTA memory shown in old wild-type mice is impaired in old EphB2lacZ/lacZ mice. The inability to form enhanced CTA long-term memory in EphB2-/- and EphB2lacZ/lacZ old mice was not caused by differences in taste perception or ability to consume fluids. Thus, our observations show that the absence of EphB2 forward signaling in old mice impairs the ability to form enhanced long-term CTA memory and indicate that EphB2 forward signaling is needed for normal memory formation in aged mice.

Factors explaining individual differences in taste sensitivity and taste modality recognition among Finnish adults

AbstractThe objective of this study was to investigate the factors affecting interindividual variation in the sense of taste among Finnish adults. Two components of taste function were examined with five established taste modalities: taste sensitivity and capability to identify taste modalities. The potential explanatory factors for taste function included gender, age, BMI, and smoking. In total, 205 volunteers participated in the study at the sensory evaluation laboratory of Functional Foods Forum. Older age (>50 years) and male gender predicted a less sensitive sense of taste in general. For umami sensitivity, high BMI along with older age predicted lower sensitivity. Additionally, taste recognition and sensitivity were related in bitter and umami tastes. Older age was also associated with a poorer capability in taste recognition. Sour–bitter, umami–salty, and salty–umami were the most frequent taste confusions.Practical applicationsThese results showed individual differences in taste perception among adult. This study can help to understand diversity in personal eating practices and food choices, which can be utilized in personal nutritional guidance and well‐being applications. We suggest that umami should be included in studies concerning taste function. There is high variation in umami perception and as umami may increase food palatability, it can be an important element in improving diet especially among elderly people. In sensory research, panelists' interindividual variation in taste perception can be wide and should be acknowledged by careful design of studies.

Sweet and Umami Taste Perception Differs with Habitual Exercise in Males.

Taste is influenced by several factors. However, whether habitual exercise level is associated with differences in taste perception has received little investigation. The aim of this study was to determine if habitual exercise is associated with differences in taste perception in men. Active (n = 16) and inactive (n = 14) males, between ages 18–55, underwent two days of sensory testing, using prototypical taste stimuli of high and low concentrations for sweet, salt, bitter, sour, umami, and carbohydrate (maltodextrin). Mean perceived intensity and hedonic ratings were recorded. Eating behaviour was assessed by the three factor eating questionnaire and food intake by EPIC food frequency questionnaire (FFQ). There were moderate to large differences between the two groups in perceived intensity for sweet taste at the high concentration and umami taste at both high and low concentrations, with active males recording a higher perceived intensity (p < 0.05 for all). The active group also recorded a greater dislike for umami low and carbohydrate low concentration (p < 0.01). Salt, bitter and sour perception did not significantly differ between the two groups. FFQ analysis showed no difference in % energy from macronutrients between the groups. Eating behaviour traits correlated with sweet taste intensity and umami taste liking, independent of activity status. Results indicated that sweet and umami taste perception differ in active compared to inactive males. Habitual exercise level should be considered in taste perception research and in product development. Whether differences in taste perception could be one factor influencing food intake and thus energy balance with habitual exercise warrants further investigation.

Effect of using tobacco on taste perception.

Background:Impaired taste perception has impact on quality of life. Tobacco is a perilous factor that contributes to an impaired taste.Objective:To evaluate and compare taste perception among tobacco chewers and nonchewers.Materials and Methods:Sixty subjects (30 tobacco chewers + 30 nonchewers as controls) were enrolled in the study for evaluating taste perception. Taste identification time using four aqueous solutions of basic tastes – sweet, salty, sour, and bitter – was recorded (in seconds) and compared between tobacco chewers and controls. The data were analyzed using Student's t-test and analysis of variance using SPSS 20 version software.Results:A statistically significant increase in taste identification time for salty taste in tobacco chewers (12.32 s) was noted compared with nonchewers (10.21 s) (P = 0.03). The average taste identification time was higher for tobacco chewers than nonchewers for sweet and salty taste. However, the average taste identification time was lower for tobacco chewers than nonchewers for sour and bitter taste. In nonchewers, the average taste identification time was 13.01, 10.21, 8.43, and 7.56 s for sweet, salty, bitter, and sour taste, respectively. In tobacco chewers, the average taste identification time was 15.16, 12.32, 7.75, and 7.04 s for sweet, salty, bitter, and sour taste, respectively.Conclusion:The results of the study demonstrated noticeable decrease in taste perception to salty taste among tobacco chewers when compared with tobacco nonchewers. There is a remarkable difference in taste perception to basic tastes among tobacco chewers and controls.

Taste Perception and Caffeine Consumption: An fMRI Study.

Caffeine is ubiquitous, yet its impact on central taste processing is not well understood. Although there has been considerable research on caffeine’s physiological and cognitive effects, there is a paucity of research investigating the effects of caffeine on taste. Here we used functional magnetic resonance imaging (fMRI) to investigate group differences between caffeine consumers and non-consumers in blood-oxygenation-level-dependent (BOLD) activation during hedonic evaluation of taste. We scanned 14 caffeine consumers and 14 caffeine non-consumers at 3 Tesla, while they rated three tastes: caffeine (bitter), sucrose (sweet), and saccharin (sweet with bitter after taste), in aqueous solutions. Differences in BOLD activation were analyzed using voxel wise independent samples t-tests within Analysis of Functional Neuroimage (AFNI). Results indicated that during the hedonic evaluation of caffeine or sucrose, caffeine non-consumers had significantly greater activation in neuronal areas associated with memory and reward. During the hedonic evaluation of saccharin, caffeine consumers had significantly greater activation in areas associated with memory and information processing. The findings suggest caffeine consumption is associated with differential activation in neuronal areas involved in reward, memory, and information processing. Further research on intensity and hedonics of bitter and sweet stimuli in caffeine consumers and non-consumers will be of great interest to better understand the nature of differences in taste perception between caffeine consumers and non-consumers.

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.

There is growing interest in relating taste perception to diet and healthy aging. However, there is still limited information on the influence of age, sex and genetics on taste acuity as well as on the relationship between taste perception and taste preferences. We have analysed the influence of age on the intensity rating of the five basic tastes: sweet, salty, bitter, sour and umami (separately and jointly in a “total taste score”) and their modulation by sex and genetics in a relatively healthy population (men and women) aged 18–80 years (n = 1020 Caucasian European participants). Taste perception was determined by challenging subjects with solutions of the five basic tastes using standard prototypical tastants (6-n-propylthiouracil (PROP), NaCl, sucrose, monopotassium glutamate and citric acid) at 5 increasing concentrations (I to V). We also measured taste preferences and determined the polymorphisms of the genes taste 2 receptor member 38 (TAS2R38), taste 1 receptor member 2 (TAS2R38) and sodium channel epithelial 1 beta subunit (SCNN1B), as TAS2R38-rs713598, TAS1R2-rs35874116 and SCNN1B-rs239345 respectively. We found a statistically significant decrease in taste perception (“total taste score”) with increasing age for all the concentrations analysed. This association was stronger for the higher concentrations (p = 0.028; p = 0.012; p = 0.005; p = 4.20 × 10−5 and p = 1.48 × 10−7, for I to V in the multivariable-adjusted models). When we analysed taste qualities (using concentration V), the intensity rating of all the 5 tastes was diminished with age (p < 0.05 for all). This inverse association differed depending on the test quality, being higher for bitter (PROP) and sour. Women perceived taste significantly more intense than men (p = 1.4 × 10−8 for total taste score). However, there were differences depending on the taste, umami being the lowest (p = 0.069). There was a complex association between the ability to perceive a taste and the preference for the same. Significant associations were, nevertheless, found between a higher perception of sour taste and a higher preference for it in women. In contrast, the higher perception of sweet was significantly associated with a higher preference for bitter in both, men and women. The TAS2R38-rs713598 was strongly associated with bitter (PROP) taste (p = 1.38 × 10−50), having a significant interaction with sex (p = 0.030). The TAS1R2-rs35874116 was not significantly associated with sweet, whereas the SCNN1B-rs239345 was associated (p = 0.040) with salty taste. In conclusion, the inverse association between age and perceived taste intensity as well as the additional influence of sex and some genetic polymorphisms give rise to large inter-individual differences in taste perception and taste preferences that should be taken into account in future studies and for applications in precision nutrition for healthy aging.

The Relationship between Single Nucleotide Polymorphisms in Taste Receptor Genes, Taste Function and Dietary Intake in Preschool-Aged Children and Adults in the Guelph Family Health Study.

Taste is a fundamental determinant of food selection, and inter-individual variations in taste perception may be important risk factors for poor eating habits and obesity. Characterizing differences in taste perception and their influences on dietary intake may lead to an improved understanding of obesity risk and a potential to develop personalized nutrition recommendations. This study explored associations between 93 single nucleotide polymorphisms (SNPs) in sweet, fat, bitter, salt, sour, and umami taste receptors and psychophysical measures of taste. Forty-four families from the Guelph Family Health Study participated, including 60 children and 65 adults. Saliva was collected for genetic analysis and parents completed a three-day food record for their children. Parents underwent a test for suprathreshold sensitivity (ST) and taste preference (PR) for sweet, fat, salt, umami, and sour as well as a phenylthiocarbamide (PTC) taste status test. Children underwent PR tests and a PTC taste status test. Analysis of SNPs and psychophysical measures of taste yielded 23 significant associations in parents and 11 in children. After adjusting for multiple hypothesis testing, the rs713598 in the TAS2R38 bitter taste receptor gene and rs236514 in the KCNJ2 sour taste-associated gene remained significantly associated with PTC ST and sour PR in parents, respectively. In children, rs173135 in KCNJ2 and rs4790522 in the TRPV1 salt taste-associated gene remained significantly associated with sour and salt taste PRs, respectively. A multiple trait analysis of PR and nutrient composition of diet in the children revealed that rs9701796 in the TAS1R2 sweet taste receptor gene was associated with both sweet PR and percent energy from added sugar in the diet. These findings provide evidence that for bitter, sour, salt, and sweet taste, certain genetic variants are associated with taste function and may be implicated in eating patterns. (Support was provided by the Ontario Ministry of Agriculture, Food, and Rural Affairs).