Taste perception and food choices

Taste Preferences at Different Ambient Temperatures and Associated Changes in Gut Microbiota and Body Weight in Mice

Taste, dietary choices, and gut microbiota are often analyzed as major factors of metabolic health. Populations living in cold or hot regions have different dietary habits. This study aims to investigate the potential association among ambient temperature, food taste preferences, and cecal microbiota community profiles in mice. By exposing mice to mixed diets containing sweet, sour, salty, and bitter flavors at low (4 °C) and high (37 °C) ambient temperatures, the taste preferences of mice at both ambient temperatures were in the order of saltiness > sweetness > bitterness > sourness. Exposing mice to sweet, sour, salty, and bitter diets, respectively, revealed that in a low-temperature environment, mice consuming salty (5.00 ± 1.49 g), sweet (4.99 ± 0.35 g), and sour (3.90 ± 0.61 g) diets had significantly higher weight gain compared to those consuming normal feeds (2.34 ± 0.43 g, p < 0.05). Conversely, in a high-temperature environment, no significant changes in body weight were observed among mice consuming different flavored diets (p > 0.05). In a low-temperature environment, mice fed sour and sweet diets showed a significant difference in the gut microbiota composition when compared to those fed a normal diet. A higher abundance of Lachnospiraceae, UBA1819, and Clostridiales was identified as the most significant taxa in the sour group, and a higher abundance of Ruminiclostridium was identified in the sweet group. These differences were associated with microbial pathways involved in carbohydrate metabolism, amino acid metabolism, and energy metabolism. A high-temperature environment exhibited only minor effects on the gut microbiota profile. Overall, our findings provide evidence for temperature-modulated responses to the taste, gut microbiota functions, and body weight changes in mice.

Food Acquirability: An Unexplored Component of Food Security?

The key elements, or pillars, of food security are stated as food availability, food access, food utilization, and stability. These food security pillars are often linked to food security interventions at the national, community or household level. However, if the urban 'household' is the unit of interest for any food security intervention, this research asks if a more holistic element, or pillar, is needed. The aim of this research has been to explore the socio-economic aspects of food security/insecurity that we have termed as a result of the research "food acquirability". Through the use of structured questionnaires (n = 120), and analysis of the data derived from local market and supermarket settings in the city of Awka, Nigeria, the concept of food acquirability has emerged and been conceptualized and critiqued. The contribution of this paper is to frame the concept of acquirability with regard to food security in Nigeria in order to develop a better understanding of the factors that impact household urban food security/insecurity and how they can be effectively mitigated. Factors of acquirability that emerged were culture, time poverty, resource availability and cooking skills, and household food preference and meal choice.

Evaluating eating behavior traits of virtual targets: Attitudes and empathy

There are many common stereotypes related to food consumption and eating behaviors that are considered indicative of one's personal character. Negative evaluations of an individual based on their eating behaviors may lead to stigmatization and other harmful psychosocial outcomes. Using vignette scenarios, we examined 582 participants' attitudes towards two target characters who exhibited bitter food dislike and high reward-based eating drive respectively. In open-ended text responses, participants were more likely to respond negatively and use stigmatizing language when describing the character with high reward-based eating drive versus the character with bitter food dislike. In addition, empathic responses depended on whether participants believed they, themselves, exhibited reward-based eating drive. Participants tended to be more empathetic and more positive towards the target who shared their own reward-based eating behaviors. Interestingly, the same was not true for those who shared bitter food distaste. These results suggest that eating behaviors that are perceived as more controllable and unusual may be more negatively perceived. Targeted education or support to reduce negative attitudes about such traits may be beneficial.

An Investigation of TAS2R38 Haplotypes, Dietary Intake, and Risk Factors for Chronic Disease in the Canadian Longitudinal Study on Aging

BACKGROUND

Variation in common taste receptor type 2 member 38 (TAS2R38) haplotypes is associated with bitter-taste sensitivity, but associations with dietary intake and risk factors for chronic disease are inconsistent.

OBJECTIVES

To determine whether common TAS2R38 haplotypes are associated with dietary intake and risk factors for chronic disease using cross-sectional data from the Canadian Longitudinal Study on Aging (n = 26,090). Outcomes were assessed among the full sample and stratified by sex.

METHODS

Taster status was determined from TAS2R38 haplotypes, and the respondents were classified as supertasters, tasters, and nontasters. Primary outcome variables were the consumption frequencies of vegetables, sweet-tasting foods, alcoholic beverages, and visceral adiposity index (VAI). Secondary outcome variables were the individual VAI components. Multivariable regression models adjusted for sociodemographic and lifestyle factors were used to assess associations between the taster status and outcome variables.

RESULTS

Among the sample, 5655, 12,821, and 7614 respondents were classified as supertasters, tasters, and nontasters, respectively. Vegetable consumption was significantly higher among nontasters than among supertasters (1.23 ± 0.26 and 1.20 ± 0.22, respectively, P = 0.02). Among males, the consumption of sweet-tasting foods (0.40 ± 8.80 and 0.38 ± 7.55, P = 0.02) and green salad (0.35 ± 0.31 and 0.33 ± 0.27, P = 0.02) was also higher for nontasters than supertasters. Nontasters were more likely to be regular alcohol consumers compared with supertasters among the full sample (odds ratio [95% confidence interval]: 1.12 [1.03, 1.22]; P = 0.01) and among females (OR: 1.13; 95% CI: 1.01, 1.27; P = 0.04). No significant associations were observed between TAS2R38 haplotypes and VAI, although high-density lipoprotein cholesterol was significantly lower among supertasters than nontasters (1.45 ± 0.59 and 1.47 ± 0.63, respectively; P = 0.04).

CONCLUSIONS

Among middle- to older-aged adults, minor associations are observed between TAS2R38 haplotypes, dietary intake, and high-density lipoprotein cholesterol. Genetic predisposition to bitter-taste sensitivity is linked to diet; however, further research is needed to understand the relevance for chronic disease risk.

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.

Taste Preference-Related Genetic Polymorphisms Modify Alcohol Consumption Behavior of the Hungarian General and Roma Populations

Harmful alcohol consumption has been considered a major public health issue globally, with the amounts of alcohol drunk being highest in the WHO European Region including Hungary. Alcohol consumption behaviors are complex human traits influenced by environmental factors and numerous genes. Beyond alcohol metabolization and neurotransmitter gene polymorphisms, taste preference-related genetic variants may also mediate alcohol consumption behaviors. Applying the Alcohol Use Disorders Identification Test (AUDIT) we aimed to elucidate the underlying genetic determinants of alcohol consumption patterns considering taste preference gene polymorphisms (TAS1R3 rs307355, TAS2R38 rs713598, TAS2R19 rs10772420 and CA6 rs2274333) in the Hungarian general (HG) and Roma (HR) populations. Alcohol consumption assessment was available for 410 HG and 387 HR individuals with 405 HG and 364 HR DNA samples being obtained for genotyping. No significant associations were found between TAS1R3 rs307355, TAS2R19 rs10772420, and CA6 rs2274333 polymorphisms and alcohol consumption phenotypes. Significant associations were identified between TAS2R38 rs713598 and the number of standard drinks consumed in the HG sample (genotype GG negatively correlated with the number of standard drinks; coef: -0.136, p = 0.028) and the prevalence of having six or more drinks among Roma (a negative correlation was identified in the recessive model; genotype GG, coef: -0.170, p = 0.049), although, none of these findings passed the Bonferroni-corrected probability criterion (p > 0.05). Nevertheless, our findings may suggest that alcohol consumption is partially driven by genetically determined taste preferences in our study populations. Further studies are required to strengthen the findings and to understand the drivers of alcohol consumption behavior in more depth.

Variations in the TAS2R38 gene among college students in Hubei

BACKGROUND

The bitter taste receptor gene TAS2R38 is a member of the human TAS2R gene family. Polymorphisms in TAS2R38 affect the ability to taste the bitterness of phenylthiourea (PTC) compounds, thus affecting an individual's food preference and health status.

METHODS

We investigated polymorphisms in the TAS2R38 gene and the sensitivity to PTC bitterness among healthy Chinese college students in Hubei province. The association of TAS2R38 polymorphisms and PTC sensitivity with body mass index (BMI), food preference, and health status was also analyzed. A total of 320 healthy college students were enrolled (male: 133, female: 187; aged 18-23 years). The threshold value method was used to measure the perception of PTC bitterness, and a questionnaire was used to analyze dietary preferences and health status. Polymerase chain reaction (PCR) was used to analyze polymorphisms at three common TAS2R38 loci (rs713598, rs1726866, and rs10246939).

RESULTS

In our study population, 65.00% of individuals had medium sensitivity to the bitterness of PTC; in contrast, 20.94% were highly sensitive to PTC bitterness, and 14.06% were not sensitive. For the TAS2R38 gene, the PAV/PAV and PAV/AAI diplotypes were the most common (42.19% and 40.63%, respectively), followed by the homozygous AVI/AVI (8.75%) and PAV/AVI (5.00%) diplotypes.

CONCLUSION

There was a significant correlation between the sensitivity to PTC bitterness and sex, but there was no correlation between the common diplotypes of TAS2R38 and gender. Polymorphisms in the TAS2R38 gene were associated with the preference for tea, but not with one's native place, BMI, health status, or other dietary preferences. There was no significant correlation between the perception of PTC bitterness and one's native place, BMI, dietary preference, or health status. We hope to find out the relationship between PTC sensitivity and TAS2R38 gene polymorphisms and dietary preference and health status of Chinese population through this study, providing relevant guidance and suggestions for dietary guidance and prevention of some chronic diseases in Chinese population.

Impact of the Gut-Brain Hormonal Axis and Enteric Peptides in the Development of Food Neophobia in Children with Genetically Determined Hypersensitivity to the Bitter Taste

Objective: The aim of this prospective study was to determine the role of the gut-brain hormonal axis and the effect of the enteric peptides, as well as the role of genetically determined sensitivity to the bitter taste, on the development of child food neophobia (CFN). Methods: 114 children were enrolled in the study: 43 in food neophobia group (FNG), 21 In the control group (CG) and 50 in prospective group (PG). All patients were assessed with the child food neophobia scale (CFNS), underwent an oral 6-propylthiouracil (6-PROP) test, buccal swab for bitter-taste genotyping, anthropometric measurements, and were tested for serum levels of leptin, adiponectin, insulin-like growth factor-1(IGF-1), ghrelin, and neuropeptide Y (NPY), and complete blood count (CBC); measurements were taken from a blood sample after 4 h fasting. Results: Subjects from FNG were more often hypersensitive to bitter taste (6-PROP) than CG (p = 0.001). There was no correlation between the result of genetic analysis and CFNS (p = 0.197), nor the body mass index (BMI) at the age of 18–36 months (p = 0.946) found. Correlation between 6-PRO perception and genotype have not been confirmed (p = 0.064). The score of CFNS was positively related to the serum level of NPY (p = 0.03). BMI percentile was negatively related to serum level of NPY (p = 0.03), but positively related to leptin serum level (p = 0.027). Conclusions: Bitter taste sensitivity to 6-PROP plays an important role in the development of the CFN, but correlation between 6-PROP perception and genotype have not been confirmed. Children with food neophobia due to elevated serum NPY level should be constantly monitored in order to control the nutritional status at a later age.

Anatomophysiological relationships and clinical considerations of taste and smell loss in patients with COVID-19

BACKGROUND

There are numerous conflicting discussions about the outbreak of the new coronavirus 2019 (COVID-19).

AIM

To present some anatomical and physiological considerations about two of the symptoms reported by patients: The loss or reduction of smell and taste.

METHODS

The loss or reduction of smell and taste is presented in a peculiar way, with some cases of persistence even after COVID-19. For this, it was searched in three databases, PubMed/MEDLINE, Web of Science, and Scopus, using the following keywords: "Smell", "Taste", "Smell AND COVID-19", "Taste AND COVID-19", with no publication time restriction, only in English with full text available, excluding also brief communications, letters to the editor, editorials, reviews, comments, and conference abstracts.

RESULTS

The search found 776 articles in the PubMed/MEDLINE database, 1018 in the Web of Science database, and 552 in the Scopus database, from which duplicates were removed (104 articles). Finally, 17 studies were selected for detailed analysis within the eligibility criteria, with titles and abstracts related to central nervous system lesions responsible for smell and taste. This review suggests that viral mechanisms of action may be related to lesions both at the local level and at the level of the central nervous system, lasting up to 3 to 4 wk. It is considered persistent if it exceeds this period, as reported in one case in this review. There are still few studies about the treatment, and among those addressed in this review, only two studies reported possible treatments and emphasized the scarcity of data, with the best option being treatments that do not cause harm, such as gustatory and olfactory physiotherapy

CONCLUSION

Given the scarcity of data, this review emphasizes the importance of prevention, through the correct use of personal protective equipment by health professionals and respect for local behavioral indications. It is also emphasized, through five studies, that there is a predominance of such symptoms in patients with COVID-19, which can be a tool to control dissemination, through the early isolation of patients until the results are ready.

Exploring the Impact of Policies to Improve Geographic and Economic Access to Vegetables among Low-Income, Predominantly Latino Urban Residents: An Agent-Based Model

Modifying the food environment of cities is a promising strategy for improving dietary behaviors, but using traditional empirical methods to test the effectiveness of these strategies remains challenging. We developed an agent-based model to simulate the food environment of Austin, Texas, USA, and to test the impact of different food access policies on vegetable consumption among low-income, predominantly Latino residents. The model was developed and calibrated using empirical data from the FRESH-Austin Study, a natural experiment. We simulated five policy scenarios: (1) business as usual; (2)−(4) expanding geographic and/or economic healthy food access via the Fresh for Less program (i.e., through farm stands, mobile markets, and healthy corner stores); and (5) expanding economic access to vegetables in supermarkets and small grocers. The model predicted that increasing geographic and/or economic access to healthy corner stores will not meaningfully improve vegetable intake, whilst implementing high discounts (>85%) on the cost of vegetables, or jointly increasing geographic and economic access to mobile markets or farm stands, will increase vegetable intake among low-income groups. Implementing discounts at supermarkets and small grocers is also predicted to be an effective policy for increasing vegetable consumption. This work highlights the utility of agent-based modeling for informing food access policies.

Association of single nucleotide polymorphisms with taste and food preferences of the Hungarian general and Roma populations

It is reasonable to suppose that poor diet underlies the unfavorable health status of the Roma population of Europe. Previously in the framework of a complex health survey, fruit and vegetable consumption, quantity of sugar added, salting frequency; bitter, salty, sweet and fat taste preferences were evaluated of Hungarian (HG, n = 410) and Roma (HR, n = 387) populations. In the present study the associations of taste and food preferences with TAS1R3, CD36, SCNN1B, TRPV1, TAS2R38, TAS2R19 and CA6 polymorphisms were tested in the same samples. Genotype frequencies did not differ significantly between the two populations. Although we initially observed associations between certain genetic polymorphisms and taste and food preferences in our study samples, none of the p values remained significant after the multiple test correction. However, some of our results could be considered promising (0.05<corrected p < 0.20), which showed potential ethnicity-specific effects (CA6 rs2274333 with salty taste and raw kohlrabi preference, CD36 rs1527483 with fat taste preference, TAS2R19 rs10772420 with grapefruit preference, and TAS2R38 rs713598 with quantity of sugar added). Our results may suggest that genetics may mediate food preferences, and individuals with different ethnic background may require personalized interventions to modify diet. Further investigations with greater sample sizes are essential to explore the effect of these genetic variants on taste and food preferences.

A Difficult Pill to Swallow: An Investigation of the Factors Associated with Medication Swallowing Difficulties

BACKGROUND

Many medications are available as solid oral dosage forms such as tablets and capsules; however, some people find these medications difficult to swallow.

AIM

To identify whether certain psychological, oral sensory, and oral motor characteristics contribute to medication swallowing difficulties.

METHODS

A sample of healthy adults from two academic institutions in Brisbane were assessed for their experiences with swallowing solid oral dosage forms, food preferences, and food neophobia. The gag reflex, oral cavity size, fungiform papillae count, and chewing efficacy were also evaluated followed by a capsule-swallowing task. Primary outcome was the incidence of medication swallowing difficulties. Secondary outcomes were the association of medication swallowing difficulties with psychological, oral sensory, and oral motor factors.

RESULTS

Of 152 subjects, 32% reported difficulty swallowing tablets or capsules whole. This group was significantly more likely to have had a memory of choking on medications compared to those without medication swallowing difficulties (OR = 7.25, p < 0.05). Current medication swallowing difficulties were significantly associated with a smaller mouth cavity size (OR = 2.98, p < 0.05), a higher density of taste receptors on the tongue (OR = 3.27, p < 0.05), and were higher among those who chewed a jelly candy to non-homogenous particle size (OR = 4.1, p < 0.05). Current medication swallowing difficulties were associated with lower confidence in swallowing large capsules (000 size: OR = 0.47, 00 size: OR = 0.39, p < 0.05). No associations were found between medication swallowing difficulties and the gag reflex or food neophobia.

CONCLUSION

A combination of heightened oral perception characterized by a small oral cavity and high taste sensitivity compounded by a past choking episode on medications may be precipitating factors for medication swallowing difficulties. These factors may be helpful in identifying individuals who are more likely to experience difficulty swallowing medications.

Almli V. Investigating the Relationships between Basic Tastes Sensitivities, Fattiness Sensitivity, and Food Liking in 11-Year-Old Children

This study investigates the relationships between basic tastes and fattiness sensitivity and food liking in 11-year-old children. The basic taste sensitivity of 106 children was measured using different methods, namely detection (DT) and recognition (RT) thresholds, and taste responsiveness. Caffeine and quinine (bitter), sucrose (sweet), citric acid (sour), sodium chloride (salty), and monosodium glutamate (umami) were investigated for DT and RT at five concentrations in water solutions. In addition, taste responsiveness and liking were collected for the high-intensity concentrations. PROP (6-n-propylthiouracil) responsiveness was tested on paper strips. Fattiness sensitivity was measured by a paired comparison method using milk samples with varying fat content. Liking for 30 food items was recorded using a food-list questionnaire. The test was completed in a gamified “taste detective” approach. The results show that DT correlates with RT for all tastes while responsiveness to PROP correlates with overall taste responsiveness. Caffeine and quinine differ in bitterness responsiveness and liking. Girls have significantly lower DTs than boys for bitterness and sweetness. Food liking is driven by taste and fattiness properties, while fatty food liking is significantly influenced by fattiness sensitivity. These results contribute to a better holistic understanding of taste and fattiness sensitivity in connection to food liking in preadolescents.

Impact of Taste on Food Choices in Adolescence-Systematic Review and Meta-Analysis

Studies of adults report that perceived taste affects food choices and intake, which in turn may have an impact on health. However, corresponding evidence on adolescents is limited.  Our aim was to summarize current evidence of the impact of taste perception on food choice preferences or dietary intakes among adolescents (mean age 10-19.9 years). Systematic searches identified 13 papers, 12 cross-sectional and one cohort study published between 1 January 2000 to 20 February 2020 assessing the impact of taste (using phenotypic and/or genotypic markers) on food choices in adolescents without any disease conditions. Qualitative assessment in the current review indicated that individuals sensitive to bitter tastes often have a lower preference of bitter-tasting food and higher preference for sweet-tasting food. A meta-analysis of three studies on bitter-taste sensitivity revealed no difference in preference for bitter-tasting vegetables between bitter tasters and non-tasters (standardized mean difference (SMD) = 0.04; 95% CI: -0.18, 0.26; p = 0.72). Overall, a limited number of studies were available for review. As a result, we report no clear relationship between taste perception and food choices or intake in adolescents. More studies are needed to evaluate the link between adolescents' taste perceptions and dietary intake.

Science and Healthy Meals in the World: Nutritional Epigenomics and Nutrigenetics of the Mediterranean Diet

The Mediterranean Diet (MD), UNESCO Intangible Cultural Heritage of Humanity, has become a scientific topic of high interest due to its health benefits. The aim of this review is to pick up selected studies that report nutrigenomic or nutrigenetic data and recapitulate some of the biochemical/genomic/genetic aspects involved in the positive health effects of the MD. These include (i) the antioxidative potential of its constituents with protective effects against several diseases; (ii) the epigenetic and epigenomic effects exerted by food components, such as Indacaxanthin, Sulforaphane, and 3-Hydroxytyrosol among others, and their involvement in the modulation of miRNA expression; (iii) the existence of predisposing or protective human genotypes due to allelic diversities and the impact of the MD on disease risk. A part of the review is dedicated to the nutrigenomic effects of the main cooking methods used in the MD and also to a comparative analysis of the nutrigenomic properties of the MD and other diet regimens and non-MD-related aliments. Taking all the data into account, the traditional MD emerges as a diet with a high antioxidant and nutrigenomic modulation power, which is an example of the “Environment-Livings-Environment” relationship and an excellent patchwork of interconnected biological actions working toward human health.

Factors influencing the choice of beer: A review

Research on those variables that have been shown to influence the consumer's choice of beer is reviewed. The focus is on the choice of whether to drink beer as opposed to a beverage from another category, and to a greater extent, the choice between different types or styles of beer. Inspired by previous research on a diverse array of factors that have been shown to influence food and beverage choice, the review examines how beer choice is driven by consumer variables (covering biological, psychological, and socio-cultural factors), product-intrinsic attributes (the sensory aspects of the beer itself), product-extrinsic attributes (external sensory characteristics, such as packaging), and contextual and environmental influences. These situational factors refer to variables such as the location where choice/consumption takes place (i.e., on- versus off-trade), as well as the context, occasion, and reason for drinking. Current trends related to choice and consumption, such as the emerging interest in beer-food pairing, are also examined. The review groups these attributes which affect people's beer wanting, choice, and purchase in order to understand the beer consumer's choice process. Along with general conclusions, a number of key directions for future research are also presented, given that the relative contribution of each type of factor on consumer's choice behaviour is still unclear.

Genetic Background of Taste Perception, Taste Preferences, and Its Nutritional Implications: A Systematic Review

Background: The rise in nutrition-related morbidity and mortality requires public health intervention programs targeting nutritional behavior. In addition to socio-economical, socio-cultural, psychological determinants, taste is one of the main factors that influence food choices. Differences in taste perception and sensitivity may be explained by genetic variations, therefore the knowledge of the extent to which genetic factors influence the development of individual taste preferences and eating patterns is important for public policy actions addressing nutritional behaviors. Our aim was to review genetic polymorphisms accounting for variability in taste and food preferences to contribute to an improved understanding of development of taste and food preferences.

Methods: The electronic databases PubMed, Scopus, and Web of Science were searched using MeSH in PubMed and free text terms for articles published between January 1, 2000 and April 13, 2018. The search strategy was conducted following the PRISMA statement. The quality of the included studies was assessed by the validated Q-Genie tool.

Results: Following the PRISMA flowchart, finally 103 articles were included in the review. Among the reviewed studies, 43 were rated to have good quality, 47 were rated to have moderate quality, and 13 were rated to have low quality. The majority of the studies assessed the association of genetic variants with the bitter taste modality, followed by articles analyzing the impact of polymorphisms on sweet and fat preferences. The number of studies investigating the association between umami, salty, and sour taste qualities and genetic polymorphisms was limited.

Conclusions: Our findings suggest that a significant association exists between TAS2R38 variants (rs713598, rs1726866, rs10246939) and bitter and sweet taste preference. Other confirmed results are related to rs1761667 (CD36) and fat taste responsiveness. Otherwise further research is essential to confirm results of studies related to genetic variants and individual taste sensitivity. This knowledge may enhance our understanding of the development of individual taste and related food preferences and food choices that will aid the development of tailored public health strategy to reduce nutrition-related disease and morbidity.

A Brief Review of Genetic Approaches to the Study of Food Preferences: Current Knowledge and Future Directions

Genetic variation plays a crucial role in individual differences in food preferences which ultimately influence food selection and health. Our current understanding of this pathway has been informed through twin studies (to assess the heritability of food preferences), candidate gene studies, and genome-wide association studies (GWAS). However, most of this literature is mainly focused on genes previously identified as having taste or smell functions. New data suggests that genes not associated with taste or smell perception may be involved in food preferences and contribute to health outcomes. This review highlights these emerging findings and suggests a polygenic risk assessment approach to explore new relationships between food preferences and health risks.

General Decrease of Taste Sensitivity Is Related to Increase of BMI: A Simple Method to Monitor Eating Behavior

Background and Objectives

The present study was conducted to evaluate the relationship between taste identification ability and body mass index (BMI) by studying the response to the administration of different taste stimuli to both sides of the tongue in three different groups of subjects.

Subjects and Methods

Thirty healthy normal-weight volunteers, 19 healthy overweight subjects, and 22 obese subjects were enrolled. For each subject, the lateralization Oldfield score, body weight, height, and blood pressure were determined. The taste test is based on filter paper strips soaked with 4 taste stimuli presented at different concentrations to evoke 4 basic taste qualities (salty, sour, sweet, and bitter); pure rapeseed oil and water were also administered to evoke fat and neutral taste qualities. The stimuli were applied to each side of the protruded tongue. Subjects were asked to identify the taste from a list of eight descriptions according to a multiple choice paradigm.

Results

The results showed a general lowering of taste sensitivity with the increase of BMI, except for the taste of fat with rapeseed oil as the stimulus. Other variables affecting taste sensitivity are age (negative association), gender (women generally show higher sensitivity), and taste stimuli concentration (positive association).

Conclusions

Our findings could provide important insights into how new therapies could be designed for weight loss and long-term weight maintenance and how diets could be planned combining the correct caloric and nutritional supply with individual taste preferences.

Perbedaan Tingkat Keragaman Pangan Balita dan Tingkat Pendidikan Orang Tua di Rumah Tangga Kawasan Rumah Pangan Lestari (KRPL) Dan Non KRPL

Background: Sustainable Reserve Food Garden Area (KRPL) is program that to increase family dietary diversity, such as children. Children’s dietary diversity can affect to nutritional adequacy and can impact to growth process. The factor that can affect successful of KRPL program is parents’ education level.Objectives: The purpose of this study was to identify the difference between children’s dietary diversity level, household income level, and parents’ education level in sustainable reserve food garden area (KRPL) and non KRPL household in Kamal sub-district, Bangkalan district, Madura.  Method: This was an observational study with case control comparative study design was conducted among 25 children in KRPL area and 25 children in non KRPL area with mother or other family member as respondents. Simple random sampling method was used to select the samples. Children and parents’ characteristic were asked to answer structured questionnaire. Children dietary diversity level was asked by Individual Dietary Diversity Score (IDDS) instrument. The data was analyzed with Mann Whitney statistic test. Result: Children that involved in this study, either in KRPL or non KRPL area, was less than the same 35 months old (52%). Children from KRPL area was mostly girls (64%), while children from non KPRL area was mostly boys (56%). Children dietary diversity condition in KRPL area was low (52%), while children dietary diversity level in non KRPL area was sufficient (64%). Children who lived in KRPL area not always have diverse intake. The result showed that there was no difference between children dietary diversity level in KRPL and non KRPL area (p=0.259). Household income level on KRPL area was higher (68%) if compared to household on non KRPL area (44%). Parents’ education level in KRPL area was classified high (father=88%, mother=88%), while that parents’ education level in non KRPL area classified low (father=88%, mother=100%) (p=0.000). Parents in KRPL area have higher education level compare to parents in non KPRL area. Conclusion: Children dietary diversity in KRPL area are not different with non KRPL area. Children who lived in KRPL area not always have diverse intake. There is difference between household’s income level and parents’ education level. Household in KRPL area have higher income and parents in KRPL area have higher education level compare to households and parents in non KPRL area. ABSTRAKLatar Belakang: Kawasan Rumah Pangan Lestari (KRPL) merupakan program yang bertujuan untuk memperbaiki dan meningkatkan keragaman pangan keluarga, salah satunya balita. Keragaman pangan pada balita dapat berpengaruh pada kecukupan kebutuhan gizi dan berdampak pada proses pertumbuhannya. Salah satu faktor yang dapat mempengaruhi keberhasilan program KPRL adalah tingkat pendidikan orang tua.Tujuan: Tujuan dari penelitian ini adalah untuk mengidentifikasi perbedaan tingkat keragaman pangan balita dan tingkat pendapatan keluarga, dan tingkat pendidikan orang tua di rumah tangga Kawasan Rumah Pangan Lestari (KRPL) dan non KRPL Kecamatan Kamal, Kabupaten Bangkalan, Madura.Metode: Penelitian observasional dengan rancang bangun penelitian potong lintang komparatif dilakukan pada subjek penelitian yang terdiri dari 25 balita di wilayah KRPL dan 25 balita di wilayah non KRPL dengan ibu atau anggota keluarga lainnya sebagai responden. Metode simple random sampling digunakan untuk memilih sampel. Karakteristik balita dan orang tua ditanyakan melalui kuesioner. Tingkat keragaman pangan balita ditanyakan melalui instrumen Individual Dietary Diversity Score (IDDS) Data dianalisis menggunakan uji statistik Mann Whitney.Hasil: Balita yang terlibat dalam penelitian ini, baik di area KPRL maupun non KPRL, sebagian besar berusia kurang dari sama dengan 35 bulan (52%). Balita yang berasal dari wilayah KRPL sebagian besar perempuan (64%), sedangkan dari wilayah non KPRL sebagian besar laki-laki (56%). Kondisi tingkat keragaman pangan balita di wilayah KRPL tergolong rendah (52%), sedangkan tingkat keragaman pangan balita di wilayah non KRPL tergolong cukup (64%). Balita yang tinggal di rumah tangga KRPL tidak selalu mengonsumsi makanan yang beragam. Hasil penelitian menunjukkan bahwa tidak terdapat perbedaan tingkat keragaman pangan balita di wilayah KRPL dan non KPRL (p=0,259). Tingkat pendapatan keluarga balita di wilayah KRPL lebih tinggi (68%) apabila dibandingkan dengan wilayah non KPRL (44%). Tingkat pendidikan orang tua di wilayah KRPL tergolong tinggi (ayah=88%, ibu=88%), sedangkan tingkat pendidikan orang tua di wilayah non KRPL tergolong rendah (ayah=88%, ibu=100%) (p=0,000).Kesimpulan: Tingkat keragaman pangan balita di area KRPL tidak berbeda dengan balita di area non KPRL. Terdapat perbedaan tingkat pendapatan keluarga dan tingkat pendidikan orang tua balita. Keluarga di wilayah KRPL memiliki tingkat pendapatan yang lebih tinggi dan orang tua di area KRPL memiliki tingkat pendidikan lebih tinggi apabila dibandingkan dengan rumah tangga dan orang tua di wilayah non KPRL.

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.

In Vivo Biofilm Formation, Gram-Negative Infections and TAS2R38 Polymorphisms in CRSw NP Patients

OBJECTIVES

Among the predisposing factors implicated in the immune response to airway bacterial infections, genetic variations of the bitter taste receptor TAS2R38, which is expressed in the cilia of the human sinonasal epithelial cells, seem to be associated with susceptibility to chronic rhinosinusitis (CRS) and in vitro biofilm formation. Polymorphisms in TAS2R38 generate two common haplotypes: the nonfunctional AVI (Alanine, Valine, Isoleucine) and the functional PAV (Proline, Alanine, Valine) alleles, with the latter protecting against gram-negative sinonasal infections. The aim of this study is to investigate for the first time the relevance of TAS2R38 genetic variants in the susceptibility to bacterial infections associated with in vivo biofilm formation in chronic rhinosinusitis with nasal polyps (CRSwNP) patients.

STUDY DESIGN

A prospective study on 100 adult patients undergoing functional endoscopic sinus surgery (FESS) for CRSwNP.

METHODS

Propylthiouracile (PROP) testing and TAS2R38 genotyping were applied to characterize patients for receptor functionality. Sinonasal mucosa samples were processed for microbiological examination and biofilm detection.

RESULTS

The nonfunctional genotype is more frequent among CRS patients than in the general population (25% vs. 18.4%, P = 0.034). Airway gram-negative infections are primarily associated with the AVI haplotype (88.9% vs. 11.1% PAV/PAV-functional genotype, P = 0.023). Biofilm formation is prevalent in CRS patients with the AVI nontaster phenotype (62.5% vs. 33.3% PAV taster or supertaster phenotype, P = 0.05).

CONCLUSION

Our findings confirm an inverse correlation between TAS2R38 functionality and gram-negative infections in Italian patients with CRSwNP. In addition, for the first time we demonstrated a relationship between in vivo microbial biofilm and TAS2R38 receptor variants.

LEVEL OF EVIDENCE

2b. Laryngoscope, 128:E339-E345, 2018.

A novel quantified bitterness evaluation model for traditional Chinese herbs based on an animal ethology principle

Traditional Chinese herbs (TCH) are currently gaining attention in disease prevention and health care plans. However, their general bitter taste hinders their use. Despite the development of a variety of taste evaluation methods, it is still a major challenge to establish a quantitative detection technique that is objective, authentic and sensitive. Based on the two-bottle preference test (TBP), we proposed a novel quantitative strategy using a standardized animal test and a unified quantitative benchmark. To reduce the difference of results, the methodology of TBP was optimized. The relationship between the concentration of quinine and animal preference index (PI) was obtained. Then the PI of TCH was measured through TBP, and bitterness results were converted into a unified numerical system using the relationship of concentration and PI. To verify the authenticity and sensitivity of quantified results, human sensory testing and electronic tongue testing were applied. The quantified results showed a good discrimination ability. For example, the bitterness of Coptidis Rhizoma was equal to 0.0579 mg/mL quinine, and Nelumbinis Folium was equal to 0.0001 mg/mL. The validation results proved that the new assessment method for TCH was objective and reliable. In conclusion, this study provides an option for the quantification of bitterness and the evaluation of taste masking effects.

Is food refusal in autistic children related to TAS2R38 genotype?

Several studies suggest that atypical eating behaviors, in particular food selectivity, are more frequent in children with autism spectrum disorder (ASD). A link between bitter taste perception, namely PROP/PTC sensitivity and food preferences is known in healthy children. The aim of this study is to investigate whether genetic variants of the TAS2R38 taste receptor responsible for different bitter sensitivity could affect foods preferences and consequently food refusal in ASD children. We recruited 43 children with ASD and 41 with normotypic development (TD) with or without food selectivity, aged between 2 and 11 years. Children were characterized for bitter sensitivity by means of PROP strips and FACS analysis and genotyped for TAS2R38 polymorphisms. Food selectivity was assessed by a validated food preference questionnaire filled by parents. A statistically significant correlation between PROP sensitivity and food refusal was observed. Furthermore, a prevalence of the PAV-sensitive haplotype compared to the AVI-insensitive one was seen in ASD children with food selectivity. In agreement with the initial hypothesis the results show that food refusal in ASD children is mediated by bitter taste sensitivity thus suggesting that the bitter sensitivity test may be used as a device to orientate tailored food proposals for the practical management of food selectivity in ASD. Autism Res 2018, 11: 531-538. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

A variation of the gene TAS2R38, associated with bitter taste sensitivity, can cause a different perception of some foods. In particular, some children are hypersensitive to bitterness and show a more restricted repertoire of accepted foods. We evaluate bitter sensitivity in ASD children with or without food selectivity, through a simple bitter taste test with edible strips. The results show that food refusal in ASD children can be mediated by bitter taste sensitivity thus suggesting that the bitter sensitivity test may be used as a device to orientate tailored food proposals for the practical management of food selectivity in ASD.

Multisensory influence on eating behavior: Hedonic consumption

Research in obesity has traditionally focused on prevention strategies and treatments aimed at changing lifestyle habits. However, recent research suggests that eating behavior is a habit regulated not only by homeostatic mechanisms, but also by the hedonic pathway that controls appetite and satiety processes. Cognitive, emotional, social, economic, and cultural factors, as well as organoleptic properties of food, are basic aspects to consider in order to understand eating behavior and its impact on health. This review presents a multisensory integrative view of food at both the homeostatic and non-homeostatic levels. This information will be of scientific interest to determine behavior drivers leading to overeating and, thus, to propose effective measures, at both the individual and population levels, for the prevention of obesity and associated metabolic diseases.

Taste sensitivity of adults and elderly persons

Abstract Objective: To compare the taste sensitivity of adults and elderly people, considering nutritional status, smoking and alcohol consumption. Method: Forty-six volunteers participated in the research, thirteen of whom were adult employees of a company from the food industry and thirty-three of whom were elderly residents of three Long-Term Care Facilities for the Elderly from the Vale do Taquari (Taquari Valley). They responded to a structured questionnaire about their socioeconomic data and use of medication, smoking and alcohol consumption, and underwent a nutritional evaluation and a taste sensitivity test. The taste sensitivity test was applied at three different concentrations for every flavor, with 4 drops dripped on the tongue of the volunteer, who described the level of perceived palatability, giving a score of 0-5. Data was analyzed through statistical analysis using the Statistical Package SPSS 20.0, considering a value of significance of p<0.05. Result: a reduction in the taste sensitivity of the elderly persons was noted for the sweet and sour solutions, in comparison with adults, as the majority of the elderly people demonstrated lower sensitivity scale scores for the citric acid solution in concentration 1 (p=0.004) and concentration 2 (p=0.049) and sucrose in concentration 3 (p=0.026). Conclusion: Elderly people had a lower perception of the sweet and sour flavors than adults. Moreover, nutritional status, gender, alcohol consumption, smoking and medication use were not significantly associated with the taste perception of the individuals evaluated.

Association of TAS2R38 variants with sweet food intake in children aged 1-6 years

We aimed at studying whether genetic variants of the TAS2R38 gene are associated with energy intake from sweet tasting foods, total energy and macronutrient intake and body weight in children. Children (n = 691) from five European countries were genotyped for the first variant site rs713598 of the TAS2R38 bitter receptor gene. Three-day dietary records were obtained yearly from one to six years of age. Foods were categorized in sweet and non-sweet-tasting. Mixed models were used to describe group differences in food and nutrient intake and BMI z-score over time. TAS2R38 genotype was related to energy intake from sweet tasting foods: Children with PP and PA genotype consumed an average 83 kJ/d (95% CI 21 to 146; p = 0.009) more sweet tasting foods than children with AA genotype and a mean 56 kJ/d (95% CI 15 to 98; p = 0.007) more energy from energy dense sweet products. Intake of sweet tasting foods was lower in girls than boys and differed between countries. TAS2R38 genotype was not associated with the intake of energy, macronutrients, sugar, single food groups and BMI z-score. Despite many other factors influencing food preference and intake in children, actual intake of sweet food items is associated with TAS2R38 genotype. Children with PP or PA genotype consume more (energy dense) sweet tasting foods.

Picky eating: Associations with child eating characteristics and food intake

Food rejection behaviors such as picky eating are of concern for many parents and attempts to increase healthy food intake can cause distress at mealtimes. An important limitation in most of the picky eating studies is that they cover few characteristics of picky eating behaviors and use limited measures of food intake. The objective of this study was to explore the associations between picky eating, child eating characteristics, and food intake among toddlers 12-47.9 months old (n = 2371) using data from the 2008 Feeding Infants and Toddlers Study (FITS). Logistic regression was used to examine associations between demographic and feeding characteristics and picky eater status. Differences in food group intake between picky and non-picky eaters were analyzed. Picky eaters were more likely to be neophobic, texture resistant, and to eat only favorite foods, In addition, the parents of picky eaters tend to offer new food a greater number of times than those of non-picky eaters before deciding that the child does not like it. Picky eaters showed significant lower intakes of eggs, burritos/tacos/enchiladas/nachos and sandwiches than non-picky eaters. Picky eaters consumed fewer vegetables from the "other vegetables" category and less raw vegetables than non-picky eaters. Neophobia, eating only favorite foods and difficulties with texture are all important characteristics of picky eaters which need to be integrated in studies measuring picky eating behaviors. Food intake of picky eaters differs only slightly from non-picky eaters. Because picky eating is a major parental concern, feeding strategies and advice related to the relevant characteristics of picky eating behavior need to be developed and assessed for their effectiveness.

Gene-environment Interactions in the Etiology of Dental Caries

Dental caries is a multifactorial disease that can be conceptualized as an interaction between genetic and environmental risk factors. The aim of this study is to examine the effects of AMELX, CA6, DEFB1, and TAS2R38 gene polymorphism and gene-environment interactions on caries etiology and susceptibility in adults. Genomic DNA was extracted from the buccal mucosa, and adults aged 20 to 60 y were placed into 1 of 2 groups: low caries risk (DMFT ≤ 5; n = 77) and high caries risk (DMFT ≥ 14; n = 77). The frequency of AMELX (+522), CA6 (T55M), DEFB1 (G-20A), and TAS2R38 (A49P) single-nucleotide polymorphisms was genotyped with the polymerase chain reaction-restriction fragment length polymorphism method. Environmental risk factors examined in the study included plaque amount, toothbrushing frequency, dietary intake between meals, saliva secretion rate, saliva buffer capacity, mutans streptococci counts, and lactobacilli counts. There was no difference between the caries risk groups in relation to AMELX (+522) polymorphism (χ(2) test, P > 0.05). The distribution of CA6 genotype and allele frequencies in the low caries risk group did not differ from the high caries risk group (χ(2) test, P > 0.05). Polymorphism of DEFB1 (G-20A) was positively associated, and TAS2R38 (A49P) negatively associated, with caries risk (χ(2) test, P = 0.000). There were significant differences between caries susceptibility and each environmental risk factor, except for the saliva secretion rate (Mann-Whitney U test, P = 0.000). Based on stepwise multiple linear regression analyses, dental plaque amount, lactobacilli count, age, and saliva buffer capacity, as well as DEFB1 (G-20A), TAS2R38 (A49P), and CA6 (T55M) gene polymorphism, explained a total of 87.8% of the variations in DMFT scores. It can be concluded that variation in CA6 (T55M), DEFB1 (G-20A), and TAS2R38 (A49P) may be associated with caries experience in Turkish adults with a high level of dental plaque, lactobacilli count, and age and when saliva buffer capacity is low.

Predicting gender differences in liking for vegetables and preference for a variety of vegetables among 11-year-old children

We studied the factors that predict liking for vegetables and preference for a variety of vegetables among schoolchildren. Additionally, we examined if there were gender differences in the predictors that explain the hypothesized higher scores in liking vegetables and preferences among girls. The data from the PRO GREENS project included 424 Finnish children (response rate 77%) aged 11 to 12. The children completed validated measures about social and environmental factors related to their liking for vegetables and preferences both at baseline 2009 and follow-up 2010. The associations were examined with regression and mediation analyses. The strongest predictors of both girls' and boys' liking and preferences were higher levels of eating vegetables together with the family, previous vegetable intake and a lower level of perceived barriers. Liking was additionally predicted by a lower level of parental demand that their child should eat vegetables. Girls reported higher levels of liking and preferences in the follow-up. This gender difference was mainly explained by girls' lower level of perceived barriers related to vegetable intake and girls' higher previous vegetable intake. Interventions that aim to increase the low vegetable intake among boys by increasing their liking for vegetables and preference for a variety of vegetables could benefit from targeting perceived barriers, namely boys' perception and values concerning the consumption of vegetables.

Bitter taste genetics--the relationship to tasting, liking, consumption and health

Bitter is the most complex of human tastes, and is arguably the most important. Aversion to bitter taste is important for detecting toxic compounds in food; however, many beneficial nutrients also taste bitter and these may therefore also be avoided as a consequence of bitter taste. While many polymorphisms in TAS2R genes may result in phenotypic differences that influence the range and sensitivity of bitter compounds detected, the full extent to which individuals differ in their abilities to detect bitter compounds remains unknown. Simple logic suggests that taste phenotypes influence food preferences, intake and consequently health status. However, it is becoming clear that genetics only plays a partial role in predicting preference, intake and health outcomes, and the complex, pleiotropic relationships involved are yet to be fully elucidated.

Human gustation: when the brain has taste

What we put into our mouths can nourish or kill us. A new study uses state-of-the-art electroencephalogram decoding to detail how we and our brains know what we taste.

Physical approaches to masking bitter taste: lessons from food and pharmaceuticals

Many drugs and desirable phytochemicals are bitter, and bitter tastes are aversive. Food and pharmaceutical manufacturers share a common need for bitterness-masking strategies that allow them to deliver useful quantities of the active compounds in an acceptable form and in this review we compare and contrast the challenges and approaches by researchers in both fields. We focus on physical approaches, i.e., micro- or nano-structures to bind bitter compounds in the mouth, yet break down to allow release after they are swallowed. In all of these methods, the assumption is the degree of bitterness suppression depends on the concentration of bitterant in the saliva and hence the proportion that is bound. Surprisingly, this hypothesis has only rarely been fully tested using a combination of adequate human sensory trials and measurements of binding. This is especially true in pharmaceutical systems, perhaps due to the greater experimental challenges in sensory analysis of drugs.

Pharmacogenetics of taste: turning bitter pills sweet?

Poor palatability of oral drug formulations used for young children negatively influences medication intake, resulting in suboptimal treatment. Some children are more sensitive to bitter tastes than others. Bitter tasting status is currently assessed by phenotyping with 6-n-propylthiouracil (PROP) as a bitter probe. Recent studies showed that interindividual differences in PROP sensitivity can be largely explained by three SNPs in TAS2R38, encoding a bitter taste receptor. Gustin, involved in the development of taste buds, and the sweet receptor genotype potentially explain remaining parts of PROP sensitivity variability. Other TAS2 receptor bitter receptor genes may also play a role in bitter aversions. Dependent on their genotype, children may have different medication formulation preferences. Taste genetics could improve drug acceptance by enabling better-informed choices on adapting oral formulations to children’s taste preferences. This paper presents an overview of recent findings concerning bitter taste genetics and discusses these in the context of pediatric drug formulation.

Early influences on the development of food preferences

The ability to perceive flavors begins in utero with the development and early functioning of the gustatory and olfactory systems. Because both amniotic fluid and breast milk contain molecules derived from the mother's diet, learning about flavors in foods begins in the womb and during early infancy. This early experience serves as the foundation for the continuing development of food preferences across the lifespan, and is shaped by the interplay of biological, social, and environmental factors. Shortly after birth, young infants show characteristic taste preferences: sweet and umami elicit positive responses; bitter and sour elicit negative responses. These taste preferences may reflect a biological drive towards foods that are calorie- and protein-dense and an aversion to foods that are poisonous or toxic. Early likes and dislikes are influenced by these innate preferences, but are also modifiable. Repeated exposure to novel or disliked foods that occurs in a positive, supportive environment may promote the acceptance of and eventually a preference for those foods. Alternatively, children who are pressured to eat certain foods may show decreased preference for those foods later on. With increasing age, the influence of a number of factors, such as peers and food availability, continue to mold food preferences and eating behaviors.

Explaining human recreational use of 'pesticides': The neurotoxin regulation model of substance use vs. the hijack model and implications for age and sex differences in drug consumption

Most globally popular drugs are plant neurotoxins or their close chemical analogs. These compounds evolved to deter, not reward or reinforce, consumption. Moreover, they reliably activate virtually all toxin defense mechanisms, and are thus correctly identified by human neurophysiology as toxins. Acute drug toxicity must therefore play a more central role in drug use theory. We accordingly challenge the popular idea that the rewarding and reinforcing properties of drugs "hijack" the brain, and propose instead that the brain evolved to carefully regulate neurotoxin consumption to minimize fitness costs and maximize fitness benefits. This perspective provides a compelling explanation for the dramatic changes in substance use that occur during the transition from childhood to adulthood, and for pervasive sex differences in substance use: because nicotine and many other plant neurotoxins are teratogenic, children, and to a lesser extent women of childbearing age, evolved to avoid ingesting them. However, during the course of human evolution many adolescents and adults reaped net benefits from regulated intake of plant neurotoxins.

Bitter taste perception and dietary intake patterns in irish children

BACKGROUND/AIMS

Variations in bitter receptor gene TAS2R38 affect the perception of bitter-tasting compound 6-n-propylthiouracil (PROP). The perception of PROP has been associated, in some reports, with the perception of fat and sweet tastes, and various food preferences and intakes. The aim was to investigate nutrient intakes and food patterns in a group of Irish children, using K-means cluster analysis, and compare these with TAS2R38 genotype and PROP taster status.

METHODS

Dietary intake was measured via a 3-day diet history in 483 children aged 7-13 years. Children were genotyped for TAS2R38 variation, and PROP taster status was assessed. Anthropometric and socioeconomic data were also obtained.

RESULTS

No differences were observed in macronutrient, micronutrient, or food group consumption between the TAS2R38 genotype and PROP taster groups. K-means cluster analysis identified two distinct dietary patterns, termed 'more healthful' and 'less healthful' clusters. The clusters did not differ in frequencies of TAS2R38 genotype nor PROP taster status groups, suggesting that dietary patterns are not influenced by bitter taste perception.

CONCLUSION

Bitterness perception, as measured by either TAS2R38 genotype or PROP taster status, does not appear to exert a significant effect on patterns of dietary intakes.

Spices: the savory and beneficial science of pungency

Spicy food does not only provide an important hedonic input in daily life, but has also been anedoctically associated to beneficial effects on our health. In this context, the discovery of chemesthetic trigeminal receptors and their spicy ligands has provided the mechanistic basis and the pharmacological means to investigate this enticing possibility. This review discusses in molecular terms the connection between the neurophysiology of pungent spices and the "systemic" effects associated to their trigeminality. It commences with a cultural and historical overview on the Western fascination for spices, and, after analysing in detail the mechanisms underlying the trigeminality of food, the main dietary players from the transient receptor potential (TRP) family of cation channels are introduced, also discussing the "alien" distribution of taste receptors outside the oro-pharingeal cavity. The modulation of TRPV1 and TRPA1 by spices is next described, discussing how spicy sensations can be turned into hedonic pungency, and analyzing the mechanistic bases for the health benefits that have been associated to the consumption of spices. These include, in addition to a beneficial modulation of gastro-intestinal and cardio-vascular function, slimming, the optimization of skeletal muscle performance, the reduction of chronic inflammation, and the prevention of metabolic syndrome and diabetes. We conclude by reviewing the role of electrophilic spice constituents on cancer prevention in the light of their action on pro-inflammatory and pro-cancerogenic nuclear factors like NFκB, and on their interaction with the electrophile sensor protein Keap1 and the ensuing Nrf2-mediated transcriptional activity. Spicy compounds have a complex polypharmacology, and just like any other bioactive agent, show a balance of beneficial and bad actions. However, at least for moderate consumption, the balance seems definitely in favour of the positive side, suggesting that a spicy diet, a caveman-era technology, could be seriously considered in addition to caloric control and exercise as a measurement to prevent and control many chronic diseases associate to malnutrition from a Western diet.

Relationship between bitter-taste receptor genotype and solid medication formulation usage among young children: a retrospective analysis

BACKGROUND

Children often refuse to take medication in liquid formulation because of its unpleasant taste. Recent advances in taste genetics have provided some insight into individual differences in taste among children: due to their genotype, some prefer more intense sweetness and are more sensitive to bitter tastes and thus may have different needs for medication formulation.

OBJECTIVE

The aims of this study were to: (1) test the a priori hypothesis that children with the bitter-sensitive genotypes are more likely to have experienced solid medication formulations than those with the bitter-insensitive genotype; and (2) conduct post hoc analyses to examine the relationship between genotype and most preferred level of sucrose in water because sweeteners are a common component of liquid formulations.

METHODS

The following data were obtained from healthy, 3- to 10-year-old children who participated in 1 of 5 taste-research studies: taste genotype for alleles of the bitter-taste receptor TAS2R38; data from retrospective reports of solid medication formulation usage and favorite beverage; and most preferred level of sucrose in water, as determined psychophysically.

RESULTS

Data from 448 children were included (245 girls, 203 boys; mean age, 7.8 years). Children with ≥1 bitter-sensitive allele (TAS2R38 PP or AP genotype) were more likely to have taken medication in solid formulation than were bitter-insensitive (AA genotype) children. Children with the PP genotype preferred higher concentrations of sucrose in water, and their favorite beverage contained more grams of sugar compared with children with the AA genotype.

CONCLUSIONS

Taste genotype was associated with experience with solid medication formulations and preference for more intense sweetness. This finding suggests that taste genetics might be an important factor in formulation choice and compliance in the pediatric population.