An evolutionary perspective on food and human taste

Taste perception and muscular response: EMG based experimental evaluation

Background

Taste perception influences not only flavor preference but also the physiological processes of chewing and digestion. Each primary taste-sweet, sour, salty, bitter, and umami-affects specific receptors and shapes masticatory muscle activity, notably in the temporalis and masseter muscles. Limited research exists on how taste affects muscle synergy (coordinated activation) and symmetry (balanced activation) in chewing. Using surface electromyography (EMG), this study examines how different tastes impact these muscle dynamics, offering insights relevant to dentistry, nutrition, and food science.

Methods

This study included five healthy participants aged 18-22 years. EMG recordings were conducted on the temporalis anterior and masseter muscles. Each participant chewed five distinct jelly formulations (sweet, sour, salty, bitter, umami) prepared with standardized flavours. The muscle activity was analyzed to determine the effects of taste on muscle synergy (right and left temporalis and masseter) and symmetry (temporalis and masseter). Paired t-tests and ANOVA were used to assess statistical significance.

Results

The results revealed taste-dependent variations in muscle synergy and symmetry. Sweet and salty tastes increased muscle synergy, while bitter and umami decreased it. Minimal changes were observed in the symmetry of the temporalis muscle across taste conditions, while the symmetry of the anterior masseter showed notable variations, especially with salty and umami. However, statistical analysis indicated no significant differences in muscle synergy or symmetry between jelly and non-jelly conditions across all taste stimuli (p > 0.05).

Conclusion

This study underscores the complexity of the neuromuscular response to taste perception, suggesting potential subtle influences of taste on muscle activity. Future research with a larger sample size and advanced statistical methods may further elucidate the role of taste in modulating masticatory muscle function.

TastePeptides-Meta: A One-Stop Platform for Taste Peptides and Their Structural Derivatives, Including Taste Properties, Interactions, and Prediction Models

Taste peptides have nutritional and sensory properties, and their structural derivatives show unique taste modulation effects. The increasing number of taste peptide candidates requires a fast and accurate screening methodology using advanced detection tools. Notably, existing platforms lack integrated bioinformatics solutions to provide accurate retrieval and prediction capabilities. In response to this need, TastePeptides-Meta is proposed, comprising 2,926 peptides entries, 975 peptide structural derivatives, and 954 synergistic (enhancing) data from 282, 109, and 103 peer-reviewed studies, respectively. It was equipped with corresponding machine learning-driven prediction modules and domain-specific analytical toolkits. As an online interactive platform, TastePeptides-Meta provides multiple interfaces that allow searching, downloading and predicting taste peptides. We believe that the public availability of TastePeptides-Meta and its implementation of standardized data schemas will accelerate mechanistic investigations in the field of taste peptides and the development of data-driven, interpretable models for predicting and exploring taste mechanisms. The TastePeptides-Meta platform can be accessed online at http://www.tastepeptides-meta.com/.

Perceived Taste Loss From Early Adulthood to Mid to Late Adulthood and Mortality

Importance

Evidence on the associations of taste function changes from early adulthood to mid to late adulthood with all-cause mortality is limited.

Objective

To investigate the associations between subjective perception of taste loss from early adulthood to mid to late adulthood and all-cause mortality.

Design, Setting, and Participants

This population-based cohort study used data from the US National Health and Nutrition Examination Survey (2011-2014) and linked mortality information from the National Death Index (NDI) and included adults aged 40 years and older. Data analyses were conducted between May 6, 2024, and July 22, 2024.

Exposures

Subjective decline in taste function and ability to detect basic tastes (ie, salt, sourness, sweetness, or bitterness) since the age of 25 years.

Main Outcomes and Measures

All-cause mortality was ascertained via linkage to the NDI with follow-up until December 31, 2019.

Results

Among 7340 participants (52.8% female), 662 (weighted, 8.9%) reported subjective perception of taste loss from early adulthood to mid to late adulthood. During a median (IQR) follow-up of 6.67 (5.67-7.83) years, 1011 deaths occurred. Subjective perception of taste loss was associated with a 47% higher risk of mortality (multiadjusted hazard ratio [HR], 1.47; 95% CI, 1.06-2.03). Specifically, self-reported loss in ability to taste salt (multivariable adjusted HR [aHR], 1.65; 95% CI, 1.21-2.26) and sourness (aHR, 1.69; 95% CI, 1.19-2.40) was associated with increased mortality. Self-reported decline in ability to taste bitterness was associated with increased mortality only in female participants (aHR, 1.63; 95% CI, 1.05-2.53), whereas decline in ability to taste sourness was associated with increased mortality only in male participants (aHR, 1.69; 95% CI, 1.03-2.75). Moreover, among all and female participants without perceived smell function loss, those with perceived taste function loss still had increased mortality (all participants: aHR, 1.64; 95% CI, 1.12-2.40; female participants: aHR, 1.71; 95% CI, 1.14-2.56; male participants: aHR, 1.44; 95% CI, 0.80-2.59).

Conclusions and Relevance

In this population-based cohort study, subjective perception of taste loss from early adulthood to mid to late adulthood, particularly perception of salt and sourness, was associated with increased all-cause mortality. The mortality risk associated with perceived taste loss could not be mitigated by undeteriorated smell function. These findings suggest that subjective perception of taste loss may serve as a simple and valuable indicator for screening high-risk populations in clinic and public health practice.

Preferential allosteric modulation of Otop1 channels by small molecule compounds

The Otopetrin (Otop) proteins, comprising Otop1-3, are proton-gated proton channels with key biological functions. Otop1 acts as a receptor for sour and ammonium salt tastes in mammals, but its gating mechanisms and pharmacology remain poorly understood. Here, we report the functional characterization of three small molecule positive allosteric modulators of Otop1-MFaN, HIMOP, and B2FAMP-that enhance proton gating in a pH-dependent manner, potentiating Otop1 activity under weak acidic but not strong acidic conditions. HIMOP also uniquely enhances Otop1's alkali gating. These modulators preferentially target Otop1, sparing Otop2 and Otop3, and other ion channels. MFaN activates Otop1 while preserving its core biophysical and pharmacological properties by associating with key residues on the channel's S5-6 and S11-12 loops, including a crucial arginine (R554) essential for Zn2+ and alkali activation. This study identifies important Otop1 modulators and structural elements underlying its gating, paving the way for further exploration of this ion channel.

Dietary Guidance, Sensory, Health and Safety Considerations When Choosing Low and No-Calorie Sweeteners

The growing global focus on the adverse health conditions associated with excessive sugar consumption has prompted health and policy organizations as well as the public to take a more mindful approach to health and wellness. In response, food and beverage companies have proactively innovated and reformulated their product portfolios to incorporate low and no-calorie sweeteners (LNCSs) as viable alternatives to sugar. LNCSs offer an effective and safe approach to delivering sweetness to foods and beverages and reducing calories and sugar intake while contributing to the enjoyment of eating. The objective of this paper is to enhance the understanding of LNCSs segmentation and definitions, dietary consumption and reduction guidance, front-of-package labeling, taste and sensory perception and physiology, metabolic efficacy and impact, as well as the overall safety of LNCSs and sugar.

A new perspective on obesity: perception of fat taste and its relationship with obesity

Background: Obesity, which results from a long-term positive energy balance, is affected by many factors, especially nutrition. The sensory properties of foods are associated with increased food intake through hedonic appetite. Taste perception, a component of flavor, is also responsible for increased consumption, through reward and hedonic mechanisms. Foods with high fat and energy content are among the foods that create the reward perception. The perception of fat taste, the primary taste that has recently entered the literature, may also be associated with increased food consumption and body weight. Therefore, in this review, the relationship between fat taste and obesity is examined, using the latest literature.

RESULTS

Different hypotheses have been proposed regarding the mechanism of the relationship between fat-taste perception and obesity, such as hedonic appetite, microbiota, decreased taste perception, and increased taste threshold level. In addition, some studies examining this relationship reported significant associations between the level of fat-taste perception and obesity, whereas others did not find a significant difference.

CONCLUSION

Considering the prevalence and contribution to obesity of Western-style nutrition, characterized by high amounts of fat and sugar consumption, elucidating this relationship may be an essential solution for preventing and treating obesity.

The influence of sleep on human taste function and perception: A systematic review

Sleep problems are associated with increased risk of obesity. Multiple mechanisms have been identified to support this relationship, including changes in sensory processing and food choice. Taste researchers have recently begun to explore whether changes in taste occur as a result of short-term or long-term sleep habits. A systematic review was conducted to investigate these relationships. A total of 13 studies were included in the review. Heterogeneity in both the sleep and taste measurements used was noted, and most studies failed to assess sour, bitter and umami tastes. Still, the available evidence suggests that sweet taste hedonic perception appears to be undesirably influenced by short sleep when viewed through the lens of health. That is, preferred sweetness concentration increases as sleep duration decreases. Habitual sleep and interventions curtailing sleep had minimal associations or effects on sweet taste sensitivity. Salt taste sensitivity and hedonic responses appear to be relatively unaffected by insufficient sleep, but more work is needed. Solid evidence on other taste qualities is not available at the present time.

Food-Induced Adverse Reactions: A Review of Physiological Food Quality Control, Mucosal Defense Mechanisms, and Gastrointestinal Physiology

Although food is essential for the survival of organisms, it can also trigger a variety of adverse reactions, ranging from nutrient intolerances to celiac disease and food allergies. Food not only contains essential nutrients but also includes numerous substances that may have positive or negative effects on the consuming organism. To protect against potentially harmful components, all animals have evolved defense mechanisms, which are similar to antimicrobial defenses but often come at the cost of the organism's health. When these defensive responses are exaggerated or misdirected, they can lead to adverse food reactions, where the costs outweigh the benefits. Furthermore, due to the persistent toxicity of harmful food components, the failure of defense mechanisms can also result in pathological effects triggered by food. This article review presents a food quality control framework that aims to clarify how these reactions relate to normal physiological processes. Organisms utilize several systems to coexist with symbiotic microbes, regulate them, and concurrently avoid, expel, or neutralize harmful pathogens. Similarly, food quality control systems allow organisms to absorb necessary nutrients while defending against low-quality or harmful components in food. Although many microbes are lethal in the absence of antimicrobial defenses, diseases related to microbiome dysregulation, such as inflammatory bowel disease, have significantly increased. Antitoxin defenses also come with costs and may fail due to insufficiencies, exaggerations, or misdirected actions, ultimately leading to adverse food reactions. With the changes in human diet and lifestyle, the failure of defense mechanisms has contributed to the rising incidence of food intolerances. This review explores the mechanisms of antitoxin defenses and analyzes how their failure can lead to adverse food reactions, emphasizing the importance of a comprehensive understanding of food quality control mechanisms for developing more effective treatments for food-triggered diseases.

ChemSweet: An AI-driven computational platform for next-gen sweetener discovery

Nowadays, the overconsumption of artificial sweeteners and their related adverse health impacts have proposed an urgent need to develop safe and healthy alternatives. Herein, we introduce ChemSweet, an AI-based platform for the rapid discovery of potential sweet molecules (http://chemsweet.ddai.tech) with the consideration of their physicochemical properties, sweetness profile, and health risks at the same time. Machine learning prediction models of four important physicochemical and four toxicity properties were established and integrated with the platform to evaluate the candidate molecules' biosafety and stability during the processing processes. Then, a new sweet taste prediction system was developed which ensures the sweet evaluation of six specific kinds of sweeteners. To facilitate the practical application of ChemSweet, the SuperNatural database was integrated for the rational screening of promising new sweeteners. We successfully identified 294 potential sweeteners that simultaneously meet the multiple anticipated criteria. We believe that ChemSweet will serve as a useful tool for identifying safe and healthy sweeteners while reducing the timeframe and high experimental costs.

Self-reported food liking and wanting: A factor analytic study of ratings across 49 consecutive days

Reward responses to food are thought to play an important role in highly palatable food overconsumption. In animal models, food reward responses can be decoupled into unique "liking" (in the moment enjoyment) and "wanting" (motivation/craving) components. However, research on liking and wanting has been hampered by uncertainty regarding whether liking and wanting can be reliably separated in humans. We used factor analysis to test whether ratings of liking and wanting could be empirically separated in women assessed across 49 consecutive days. Female participants (N = 688; ages 15-30) from the Michigan State University Twin Registry reported liking and wanting of foods consumed that day, and wanting of foods not consumed that day, separately for sweets (e.g., cookies), fast food (e.g., French fries), carbohydrates (e.g., bread), and whole foods (fruit, plain chicken) each evening for 49 consecutive days. We examined both average levels and daily levels of liking/wanting across the 49-day period that captured individual differences in liking/wanting over time. Across both types of analyses, liking and wanting for foods that were eaten formed a single factor rather than separate, dissociable factors, while wanting of foods not eaten formed an independent factor. At the daily level, a liking/wanting factor emerged for each individual food category (e.g., liking/wanting sweets), whereas in average analyses, a single factor emerged that collapsed across all food types (i.e., liking/wanting of all foods). Results suggest individuals have difficulty distinguishing between liking and wanting of foods they have eaten on that day but may be able to more reliably separate wanting of foods they have not consumed.

From menus to misbeliefs: Absolute frequencies of healthy and tasty dishes predict the unhealthy = tasty belief in restaurants

We examine whether the prevalence of healthy and tasty food options in restaurant menus leads to the formation of beliefs about the relationship between healthiness and taste that deviate from the correlation of healthiness and taste ratings. Participants (N = 195) rated the healthiness and taste of twelve dishes from two different restaurant types (American and vegetarian restaurants), estimated the frequencies of healthy and tasty options, and reported their health-taste beliefs. Results show that ratings of perceived healthiness and expected taste are uncorrelated in both restaurant types, but participants formed the misbelief that unhealthy dishes taste better than healthy dishes to a greater extent in American than in vegetarian restaurants. Regression analyses revealed that the absolute frequencies of food options were significantly related to participants' health-taste beliefs while controlling for the correlation between healthiness and taste ratings in both restaurant types. Participants were more likely to believe that healthy food tastes better than unhealthy food when they perceived that healthy and tasty food were both frequent (or infrequent) in the respective restaurant type. Our results provide evidence that relying on absolute frequencies, rather than covariation, to infer the relationship between healthiness and taste may lead to misbeliefs that do not reflect the health-taste correlation of individual food items.

Thinking of food: The mental representation of healthy foods as unprepared

We find that people implicitly and explicitly represent healthy foods they categorize as healthy in their purest, least prepared forms but represent foods they categorize as unhealthy in their most prepared forms (e.g., a veggie patty is represented as frozen while a beef burger is represented in a bun with melted cheese and ready to eat). We find this effect across several studies using both image and word sorting measures in explicit tasks and implicit association tasks. The effect results from the perception of health and taste as two conflicting goals. Preparation (e.g., cooking, adding toppings) makes food more delicious, which creates categorization ambiguity. Hence, healthy food is thought of as unprepared. Indeed, individual differences in perceived health-taste goal conflict moderate the effect. Critically, the representation of healthy foods matters for food decisions. In an experiment that manipulated the descriptive language on a restaurant menu, emphasizing the preparation of foods increased participants' preference for healthy foods (with no improvement for unhealthy foods).

The spatiotemporal and genetic architecture of extraoral taste buds in Astyanax cavefish

Intense environmental pressures can yield both regressive and constructive traits through complex evolutionary mechanisms. Although regression is well-studied, the biological bases of constructive features are less well understood. Cave-dwelling Astyanax fish harbor prolific extraoral taste buds on their heads, which are absent in conspecific surface-dwellers. Here, we present novel ontogenetic data demonstrating extraoral taste buds appear gradually and late in life history. This appearance is similar but non-identical in different cavefish populations, where patterning has evolved to permit taste bud re-specification across the endoderm-ectoderm germ layer boundary. Quantitative genetic analyses revealed that spatially distinct taste buds on the head are primarily mediated by two different cave-dominant loci. While the precise function of this late expansion on to the head is unknown, the appearance of extraoral taste buds coincides with a dietary shift from live-foods to bat guano, suggesting an adaptive mechanism to detect nutrition in food-starved caves. This work provides fundamental insight to a constructive evolutionary feature, arising late in life history, promising a new window into unresolved features of vertebrate sensory organ development.

Synergistic effect of combining umami substances enhances perceived saltiness

Umami substances have the potential to enhance the perception of saltiness and thus reduce sodium intake. Two sensory evaluation experiments were conducted, involving participants tasting salt solutions, and solutions with added umami substances at equal sodium concentrations. Umami substances included sodium glutamate (MSG), disodium inosinate (IMP), and the combination of them which has a synergistic effect and is a closer match to commonly-consumed foods. In Experiment 1, using the two-alternative forced-choice (2-AFC) method by 330 consumers, paired comparisons were conducted at three different sodium concentrations. The combination of MSG and IMP enhanced the perception of saltiness (p < .001 in the difference test), whereas presenting either umami substance in isolation failed to do so (p > .05 in the similarity test). Significant order effects occurred in paired comparisons. In Experiment 2, a two-sip time-intensity (TI) analysis with trained panellists verified these results and found that tasting MSG and IMP either simultaneously or successively enhanced saltiness perception at equal sodium concentrations. These findings indicate that the synergistic effect of umami substances may be the cause of saltiness enhancement, and represents a potential strategy for sodium reduction while satisfying the consumer demand for saltiness perception. Considering the application in food processing and in food pairing, umami substances can potentially be used to help to reduce salt intake in food consumption.

Adverse Food Reactions: Physiological and Ecological Perspectives

While food is essential for survival, it can also cause a variety of harmful effects, ranging from intolerance to specific nutrients to celiac disease and food allergies. In addition to nutrients, foods contain myriads of substances that can have either beneficial or detrimental effects on the animals consuming them. Consequently, all animals evolved defense mechanisms that protect them from harmful food components. These "antitoxin" defenses have some parallels with antimicrobial defenses and operate at a cost to the animal's fitness. These costs outweigh benefits when defense responses are exaggerated or mistargeted, resulting in adverse reactions to foods. Additionally, pathological effects of foods can stem from insufficient defenses, due to unabated toxicity of harmful food components. We discuss the structure of antitoxin defenses and how their failures can lead to a variety of adverse food reactions.

Predicting multiple taste sensations with a multiobjective machine learning method

Taste perception plays a pivotal role in guiding nutrient intake and aiding in the avoidance of potentially harmful substances through five basic tastes - sweet, bitter, umami, salty, and sour. Taste perception originates from molecular interactions in the oral cavity between taste receptors and chemical tastants. Hence, the recognition of taste receptors and the subsequent perception of taste heavily rely on the physicochemical properties of food ingredients. In recent years, several advances have been made towards the development of machine learning-based algorithms to classify chemical compounds' tastes using their molecular structures. Despite the great efforts, there remains significant room for improvement in developing multi-class models to predict the entire spectrum of basic tastes. Here, we present a multi-class predictor aimed at distinguishing bitter, sweet, and umami, from other taste sensations. The development of a multi-class taste predictor paves the way for a comprehensive understanding of the chemical attributes associated with each fundamental taste. It also opens the potential for integration into the evolving realm of multi-sensory perception, which encompasses visual, tactile, and olfactory sensations to holistically characterize flavour perception. This concept holds promise for introducing innovative methodologies in the rational design of foods, including pre-determining specific tastes and engineering complementary diets to augment traditional pharmacological treatments.

Distinct Sensory Hedonic Functions for Sourness in Adults

Over the last half-century, variable responses to sweetness have repeatedly been shown to fall into a small number of hedonic responses, implying that looking only at group means may can obfuscate meaningfully different response patterns. Comparative data for sourness is quite sparse, especially in adults. While increased liking with higher acid concentration has been reported for some children, in adults, sourness is classically assumed to be aversive, with a monotonic drop in liking with increasing sourness. Here, we test this assumption using a simple model system or experimental beverage in convenience samples of adults from the United States (increasing citric acid in water) and Italy (increasing citric acid in pear juice). Participants rated intensity and liking of sampled stimuli. For both cohorts, we find clear evidence of three distinct patterns of responses: a strong negative group where liking dropped with increased sourness, an intermediate group who showed a more muted drop in liking with more sourness, and a strong positive group where liking increased with more sourness. Strikingly, both cohorts showed similar proportions of response patterns, with ~63-70% in the strong negative group, and 11-12% in the strong positive group, suggesting these proportions may be stable across cultures. Notably, the three groups did not differ by age or gender. These data support the existence of different hedonic response profiles to sour stimuli in adults, once again highlighting the importance of looking at individual differences and potential consumer segments, rather than merely averaging hedonic responses across all individuals within a group.

Food drugs as drivers of therapeutic knowledge and the role of chemosensory qualities

ETHNOPHARMACOLOGICAL RELEVANCE

Chemosensory qualities of botanical drugs are important cues for anticipating physiologic consequences. Whether a botanical drug is used for both, food and medicine, or only as medicine depends on taste preferences, nutritional content, cultural background, and the individual and overall epidemiological context.

MATERIAL AND METHODS

We subjected 540 botanical drugs described in De Materia Medica having at least one oral medical application to a tasting panel. The 540 drugs were grouped into those only used for medicine (388) and those also used for food (152). The associations with chemosensory qualities and therapeutic indications were compared across the two groups. We considered 22 experimentally assessed chemosensory qualities and 39 categories of therapeutic use groups. We wanted to know, 1): which chemosensory qualities increase the probability of an orally applied botanical drug to be also used for food ? 2): which chemosensory qualities augment the probability of an orally applied botanical drug to be only used for medicine? and 3): whether there are differences in therapeutic indications between orally applied botanical drugs also used for food (food drugs) and botanical drugs applied exclusively for medicinal purposes (non-food drugs) and, if yes, how the differences can be explained.

RESULTS

Chemosensory qualities augmenting the probability of an orally applied botanical drug to be also used for food were sweet, starchy, salty, burning/hot, fruity, nutty, and cooling. Therapeutics used for diarrhoea, as libido modulators, purgatives, laxatives, for expelling parasites, breast and lactation and increasing diuresis, were preferentially sourced from food drugs while drugs used for liver and jaundice, vaginal discharge and humoral management showed significant negative associations with food dugs in ancient Greek-Roman materia medica.

CONCLUSION

Therapeutics used for ailments of body organs involved in the digestion of food and the excretion of waste products showed a tendency to be sourced from food drugs. Arguably, the daily consumption of food offered the possibility for observing post-prandial physiologic and pharmacologic effects which led to a high therapeutic versatility of food drugs and the possibility to understand benefits of taste and flavour qualities. The difference in chemosensory qualities between food drugs and non-food drugs is demarcating the organoleptic requirements of food rather than that of medicine.

The impact of cognitive distraction on gustatory perception in volunteers with obesity

Obesity, a global health challenge, is influenced by biological, behavioral, socioeconomical, and environmental factors. In our technology-driven world, distracted eating is prevalent, yet neurocognitive mechanisms behind it remain poorly understood. This study targets individuals with overweight and obesity, exploring taste perception under distraction comprehensively. Participants formed two distinct groups based on their Body Mass Index (BMI), lean and overweight/obese. During the experiment participants received gustatory stimuli while playing a Tetris game of various difficulty levels. Participants rated taste intensity and pleasantness, with linear mixed models analyzing distraction effects. Results confirmed that high distraction levels reduced perception of taste intensity (p = 0.017) and taste pleasantness (p = 0.022), with variations influenced by gender and weight status. Individuals in the overweight/obese group exhibited most profound intensity changes during distraction (p = 0.01). Taste sensitivity ratings positively correlated with BMI interacting with gender (male r = 0.227, p < 0.001; female r = 0.101, p < 0.001). Overall across both groups, female participants demonstrated higher taste sensitivity compared to male participants (p < 0.001). This study highlights the impact of cognitive distraction during consumption on taste perception, particularly in relation to weight status and gender, underscoring their significant roles in this interplay.

Does sweetness exposure drive 'sweet tooth'?

It is widely believed that exposure to sweetened foods and beverages stimulates the liking and desire for sweetness. Here we provide an updated review of the empirical evidence from human research examining whether exposure to sweet foods or beverages influences subsequent general liking for sweetness (‘sweet tooth’), based on the conclusions of existing systematic reviews and more recent research identified from a structured search of literature. Prior reviews have concluded that the evidence for a relationship between sweet taste exposure and measures of sweet taste liking is equivocal, and more recent primary research generally does not support the view that exposure drives increased liking for sweetness, in adults or children. In intervention trials using a range of designs, acute exposure to sweetness usually has the opposite effect (reducing subsequent liking and desire for sweet taste), while sustained exposures have no significant effects or inconsistent effects. Recent longitudinal observational studies in infants and children also report no significant associations between exposures to sweet foods and beverages with measures of sweet taste preferences. Overall, while it is widely assumed that exposure to sweetness stimulates a greater liking and desire for sweetness, this is not borne out by the balance of empirical evidence. While new research may provide a more robust evidence base, there are also a number of methodological, biological and behavioural considerations that may underpin the apparent absence of a positive relationship between sweetness exposure and liking.

Perceived Taste and Olfactory Dysfunctions and Subsequent Stroke Risk

Background

Taste and olfactory dysfunction are commonly associated with neurodegenerative diseases and cardiovascular risk factors, but their specific associations with stroke risk remain uncertain.

Objectives

The purpose of this paper was to explore whether perceived taste and olfactory dysfunctions were associated with stroke risk.

Methods

Included were 85,656 participants (mean age 51.0 ± 15.3 years) of the Kailuan study. Perceived olfactory and taste dysfunctions were assessed via a questionnaire at baseline (in 2014-2016). Incident stroke cases were confirmed by review of medical records. Cox proportional hazards models were used to investigate associations of perceived olfactory and taste dysfunctions with stroke risk, and mediation analysis was used to estimate the mediating effect of chronic disease statuses.

Results

We documented 2,198 incident stroke cases during a mean of 5.6 years of follow-up. Perceived taste dysfunction was associated with a doubled risk of developing total stroke (adjusted HR: 2.03; 95% CI: 1.36-3.04; P < 0.001) even with adjustment of lifestyle factors, biomarkers (ie, blood lipids, blood glucose, blood pressure, and uric acid), and other potential confounders. However, perceived olfactory dysfunction (adjusted HR: 1.22; 95% CI: 0.79-1.90; P = 0.34) was not significantly associated with a high risk of total stroke. Similar results of both perceived taste and olfactory dysfunctions were observed for ischemic stroke. Presence of chronic diseases, including hypertension, diabetes, chronic kidney disease, and overweight/obesity, mediated 4% to 5% of the association of perceived taste dysfunction with both total stroke and ischemic stroke.

Conclusions

In this large cohort study, perceived taste dysfunction was associated with a high risk of developing stroke.

The taste for health: the role of taste receptors and their ligands in the complex food/health relationship

Taste, food, and health are terms that have since always accompanied the act of eating, but the association was simple: taste serves to classify a food as good or bad and therefore influences food choices, which determine the nutritional status and therefore health. The identification of taste receptors, particularly, the G protein-coupled receptors that mediate sweet, umami, and bitter tastes, in the gastrointestinal tract has assigned them much more relevant tasks, from nutrient sensing and hormone release to microbiota composition and immune response and finally to a rationale for the gut-brain axis. Particularly interesting are bitter taste receptors since most of the times they do not mediate macronutrients (energy). The relevant roles of bitter taste receptors in the gut indicate that they could become new drug targets and their ligands new medications or components in nutraceutical formulations. Traditional knowledge from different cultures reported that bitterness intensity was an indicator for distinguishing plants used as food from those used as medicine, and many non-cultivated plants were used to control glucose level and treat diabetes, modulate hunger, and heal gastrointestinal disorders caused by pathogens and parasites. This concept represents a means for the scientific integration of ancient wisdom with advanced medicine, constituting a possible boost for more sustainable food and functional food innovation and design.

Exploring Bitter and Sweet: The Application of Large Language Models in Molecular Taste Prediction

The perception of bitter and sweet tastes is a crucial aspect of human sensory experience. Concerns over the long-term use of aspartame, a widely used sweetener suspected of carcinogenic risks, highlight the importance of developing new taste modifiers. This study utilizes Large Language Models (LLMs) such as GPT-3.5 and GPT-4 for predicting molecular taste characteristics, with a focus on the bitter-sweet dichotomy. Employing random and scaffold data splitting strategies, GPT-4 demonstrated superior performance, achieving an impressive 86% accuracy under scaffold partitioning. Additionally, ChatGPT was employed to extract specific molecular features associated with bitter and sweet tastes. Utilizing these insights, novel molecular compounds with distinct taste profiles were successfully generated. These compounds were validated for their bitter and sweet properties through molecular docking and molecular dynamics simulation, and their practicality was further confirmed by ADMET toxicity testing and DeepSA synthesis feasibility. This research highlights the potential of LLMs in predicting molecular properties and their implications in health and chemical science.

Identifying segment-specific barriers to ordering environmentally sustainable plant-based meat dishes in restaurants

Eating less meat when dining out can help mitigate climate change. Plant-based meats can facilitate the transition to a more environmentally sustainable tourism sector. However, uptake of these products remains low. Building on the capability-opportunity-motivation behaviour model, this study identifies the main reasons for the general population of restaurant patrons to reject plant-based meats: they prefer meat and traditional vegetable dishes; they are concerned about not enjoying plant-based meat dishes; they perceive plant-based meat dishes as too expensive. Accounting for heterogeneity among diners leads to the identification of six distinct consumer segments, which differ in their reasons for not ordering plant-based meat dishes in restaurants. From these empirical insights, we derive recommendations for tourism professionals on how to entice specific consumer segments to order plant-based meat dishes and identify future avenues for research.

Locus Ceruleus Dynamics Are Suppressed during Licking and Enhanced Postlicking Independent of Taste Novelty

Attending to salient sensory attributes of food, such as tastes that are new, displeasing, or unexpected, allows the procurement of nutrients without food poisoning. Exposure to new tastes is known to increase norepinephrine (NE) release in taste processing forebrain areas, yet the central source for this release is unknown. Locus ceruleus norepinephrine neurons (LC-NE) emerge as a candidate in signaling salient information about taste, as other salient sensory stimuli (e.g., visual, auditory, somatosensation) are known to activate LC neurons. To determine if LC neurons are sensitive to features of taste novelty, we used fiber photometry to record LC-NE activity in water-restricted mice that voluntarily licked either novel or familiar substances of differential palatability (saccharine, citric acid). We observed that LC-NE activity was suppressed during lick bursts and transiently activated upon the termination of licking and that these dynamics were independent of the familiarity of the substance consumed. We next recorded LC dynamics during brief and unexpected consumption of tastants and found no increase in LC-NE activity, despite their responsiveness to visual and auditory stimuli, revealing selectivity in LC's responses to salient sensory information. Our findings suggest that LC activity during licking is not influenced by taste novelty, implicating a possible role for non-LC noradrenergic nuclei in signaling critical information about taste.

A novel biomimetic electrochemical taste-biosensor based on conformational changes of the taste receptor

Taste sensor, a useful tool which could detect and identify thousands of different chemical substances in liquid environments, has attracted continuous concern from beverage and foodstuff industry and its consumers. Although many taste sensing methods have been extensively developed, the assessment of tastant content remains challenging due to the limitations of sensor selectivity and sensitivity. Here we present a novel biomimetic electrochemical taste-biosensor based on bioactive sensing elements and immune amplification with nanomaterials carrier to address above concerns, while taking sweet taste perception as a model. The proposed biosensor based on ligand binding domain (T1R2 VFT) of human sweet taste receptor protein showed human mimicking character and initiated the application of immune recognition in gustation biosensor, which can precisely and sensitively distinguish sweet substances against other related gustation substances with detection limit of 5.1 pM, far less than that of taste sensors without immune amplification whose detection limit was 0.48 nM. The performance test demonstrated the biosensor has the capacity of monitoring the response of sweet substances in real food environments, which is crucial in practical. This biomimetic electrochemical taste-biosensor can work as a new screening platform for newly developed tastants and disclose sweet perception mechanism.

A consumer evaluation of salt-reduced tomato soup and vegetable juice made with grape pomace

Obesity and obesity-related illness have become an increasingly prevalent problem and there is a critical need to combat this by reducing sugar, salt, and fat consumption. Due to this concern, the food industry has been developing salt-reduced foods, however, these products need to maintain their sensory appeal and flavors, which has proven to be a challenge. Grape pomace (GP), the solids left after pressing grapes for winemaking and consisting of grape seeds and skins, has been proposed as an environmentally friendly solution that can enhance the acceptability of salt-reduced food products. However, GP is associated with a large number of flavor compounds. As such, the objective of this research is to investigate the acceptability of GP addition in salt-reduced foods. Two trials were conducted using hedonic scales and temporal check-all-that-apply (TCATA) to evaluate tomato soup (n = 88) and vegetable juice (n = 99). Each trial included a control and sample containing grape pomace. The addition of the GP decreased the consumers' overall liking and the liking of the flavor, as well as increasing consumers' perception of saltiness intensity. The samples made with GP were associated with bitterness, sourness, and wine flavor during the TCATA evaluations. The study identified that GP increased saltiness perception, however, it also adds other flavors to the food product, which decreased the acceptability of the food items. PRACTICAL APPLICATION: There is a consumer demand to create salt-reduced foods that do not have altered sensory properties. Furthermore, consumers are interested in sustainable and environmentally friendly ingredients. Grape pomace is a byproduct of the wine industry and has been proposed as an ingredient that can increase the saltiness perception of food products. Grape pomace was added to tomato soup and vegetable juice to evaluate its effect on consumer acceptability and saltiness perception. The grape pomace did increase saltiness perception, but also added bitterness, sourness, and wine flavor to the food products.

The maps of meaning consciousness theory

In simple terms, consciousness is constituted by multiple goals for action and the continuous adjudication of such goals to implement action, which is referred to as the maps of meaning (MoM) consciousness theory. The MoM theory triangulates through three parallel corollaries: action (behavior), mechanism (morphology/pathophysiology), and goals (teleology). (1) An organism's consciousness contains fluid, nested goals. These goals are not intentionality, but intersectionality, via the Darwinian byproduct of embodiment meeting the world, i.e., Darwinian inclusive fitness or randomization and then survival of the fittest. (2) These goals are formed via a gradual descent under inclusive fitness and are the abstraction of a "match" between the evolutionary environment and the organism. (3) Human consciousness implements the brain efficiency hypothesis, genetics, epigenetics, and experience-crystallized efficiencies, not necessitating best or objective but fitness, i.e., perceived efficiency based on one's adaptive environment. These efficiencies are objectively arbitrary but determine the operation and level of one's consciousness, termed as extreme thrownness. (4) Since inclusive fitness drives efficiencies in the physiologic mechanism, morphology, and behavior (action) and originates one's goals, embodiment is necessarily entangled to human consciousness as it is at the intersection of mechanism or action (both necessitating embodiment) occurring in the world that determines fitness. (5) Perception is the operant process of consciousness and is the de facto goal adjudication process of consciousness. Goal operationalization is fundamentally efficiency-based via one's unique neuronal mapping as a byproduct of genetics, epigenetics, and experience. (6) Perception involves information intake and information discrimination, equally underpinned by efficiencies of inclusive fitness via extreme thrownness. Perception is not a 'frame rate' but Bayesian priors of efficiency based on one's extreme thrownness. (7) Consciousness and human consciousness are modular (i.e., a scalar level of richness, which builds up like building blocks) and dimensionalized (i.e., cognitive abilities become possibilities as the emergent phenomena at various modularities such as the stratified factors in factor analysis). (8) The meta dimensions of human consciousness seemingly include intelligence quotient, personality (five-factor model), richness of perception intake, and richness of perception discrimination, among other potentialities. (9) Future consciousness research should utilize factor analysis to parse modularities and dimensions of human consciousness and animal models.

VirtuousPocketome: a computational tool for screening protein-ligand complexes to identify similar binding sites

Protein residues within binding pockets play a critical role in determining the range of ligands that can interact with a protein, influencing its structure and function. Identifying structural similarities in proteins offers valuable insights into their function and activation mechanisms, aiding in predicting protein-ligand interactions, anticipating off-target effects, and facilitating the development of therapeutic agents. Numerous computational methods assessing global or local similarity in protein cavities have emerged, but their utilization is impeded by complexity, impractical automation for amino acid pattern searches, and an inability to evaluate the dynamics of scrutinized protein-ligand systems. Here, we present a general, automatic and unbiased computational pipeline, named VirtuousPocketome, aimed at screening huge databases of proteins for similar binding pockets starting from an interested protein-ligand complex. We demonstrate the pipeline's potential by exploring a recently-solved human bitter taste receptor, i.e. the TAS2R46, complexed with strychnine. We pinpointed 145 proteins sharing similar binding sites compared to the analysed bitter taste receptor and the enrichment analysis highlighted the related biological processes, molecular functions and cellular components. This work represents the foundation for future studies aimed at understanding the effective role of tastants outside the gustatory system: this could pave the way towards the rationalization of the diet as a supplement to standard pharmacological treatments and the design of novel tastants-inspired compounds to target other proteins involved in specific diseases or disorders. The proposed pipeline is publicly accessible, can be applied to any protein-ligand complex, and could be expanded to screen any database of protein structures.

Neuroscience of eating: Pace and portion control

Satiety-promoting neurons of the hindbrain have long been known for their role in meal termination. An innovative new study now reveals how different hindbrain cell types mediate appetite on distinct timescales.

Post-COVID-19 patients suffer from chemosensory, trigeminal, and salivary dysfunctions

Recent literature indicates that post-COVID-19 patients suffer from a plethora of complications, including chemosensory dysfunction. However, little attention has been given to understand the interactions between chemosensory, trigeminal, and salivary dysfunctions in these patients. The aims of this study were (1) to investigate the prevalence and combinations of chemosensory, trigeminal, and salivary dysfunctions, (2) to identify the odorants/tastants that are compromised, and (3) to explore possible associations between the four dysfunctions in post-COVID-19 patients. One hundred post-COVID-19 patients and 76 healthy controls (pre-COVID-19) were included in this cross-sectional, case-controlled study. Participants' smell, taste, trigeminal, and salivary functions were assessed. The patients had a significantly higher prevalence of parosmia (80.0%), hyposmia (42.0%), anosmia (53.0%), dysgeusia (34.0%), complete ageusia (3.0%), specific ageusia (27.0%), dysesthesia (11.0%) and dry mouth (18.0%) compared to controls (0.0% for all parameters, except 27.6% for hyposmia). Complete loss of bitter taste was the most prevalent specific ageusia (66.7%) and coffee was the most common distorted smell (56.4%). Seven different combinations of dysfunction were observed in the patients, the most common being a combination of olfactory and gustatory dysfunction (48.0%). These findings indicate that post-COVID-19 patients experience a range of chemosensory, trigeminal, and salivary disturbances, occurring in various combinations.

Taste shaped the use of botanical drugs

The perception of taste and flavour (a combination of taste, smell, and chemesthesis), here also referred to as chemosensation, enables animals to find high-value foods and avoid toxins. Humans have learned to use unpalatable and toxic substances as medicines, yet the importance of chemosensation in this process is poorly understood. Here, we generate tasting-panel data for botanical drugs and apply phylogenetic generalised linear mixed models to test whether intensity and complexity of chemosensory qualities as well as particular tastes and flavours can predict ancient Graeco-Roman drug use. We found chemosensation to be strongly predictive of therapeutic use: botanical drugs with high therapeutic versatility have simple yet intense tastes and flavours, and 21 of 22 chemosensory qualities predicted at least one therapeutic use. In addition to the common notion of bitter tasting medicines, we also found starchy, musky, sweet, and soapy drugs associated with versatility. In ancient Greece and Rome, illness was thought to arise from imbalance in bodily fluids or humours, yet our study suggests that uses of drugs were based on observed physiological effects that are often consistent with modern understanding of chemesthesis and taste receptor pharmacology.

Nutritional epigenetics education improves diet and attitude of parents of children with autism or attention deficit/hyperactivity disorder

BACKGROUND

Unhealthy maternal diet leads to heavy metal exposures from the consumption of ultra-processed foods that may impact gene behavior across generations, creating conditions for the neurodevelopmental disorders known as autism and attention deficit/hyperactivity disorder (ADHD). Children with these disorders have difficulty metabolizing and excreting heavy metals from their bloodstream, and the severity of their symptoms correlates with the heavy metal levels measured in their blood. Psychiatrists may play a key role in helping parents reduce their ultra-processed food and dietary heavy metal intake by providing access to effective nutritional epigenetics education.

AIM

To test the efficacy of nutritional epigenetics instruction in reducing parental ultra-processed food intake.

METHODS

The study utilized a semi-randomized test and control group pretest-posttest pilot study design with participants recruited from parents having a learning-disabled child with autism or ADHD. Twenty-two parents who met the inclusion criteria were randomly selected to serve in the test (n = 11) or control (n = 11) group. The test group participated in the six-week online nutritional epigenetics tutorial, while the control group did not. The efficacy of the nutritional epigenetics instruction was determined by measuring changes in parent diet and attitude using data derived from an online diet survey administered to the participants during the pre and post intervention periods. Diet intake scores were derived for both ultra-processed and whole/organic foods. Paired sample t-tests were conducted to determine any differences in mean diet scores within each group.

RESULTS

There was a significant difference in the diet scores of the test group between the pre- and post-intervention periods. The parents in the test group significantly reduced their intake of ultra-processed foods with a pre-intervention diet score of 70 (mean = 5.385, SD = 2.534) and a post-intervention diet score of 113 (mean = 8.692, SD = 1.750) and the paired t-test analysis showing a significance of P < 0.001. The test group also significantly increased their consumption of whole and/or organic foods with a pre-intervention diet score of 100 (mean = 5.882, SD = 2.472) and post-intervention diet score of 121 (mean = 7.118, SD = 2.390) and the paired t-test analysis showing a significance of P < 0.05.

CONCLUSION

Here we show nutritional epigenetics education can be used to reduce ultra-processed food intake and improve attitude among parents having learning-disabled children with autism or ADHD.

Ribonucleotides differentially modulate oral glutamate detection thresholds

The savory or umami taste of the amino acid glutamate is synergistically enhanced by the addition of the purines inosine 5'-monophosphate (IMP) and guanosine 5'-monophosphate (GMP) disodium salt. We hypothesized that the addition of purinergic ribonucleotides, along with the pyrimidine ribonucleotides, would decrease the absolute detection threshold of (increase sensitivity to) l-glutamic acid potassium salt (MPG). To test this, we measured both the absolute detection threshold of MPG alone and with a background level (3 mM) of 5 different 5'-ribonucleotides. The addition of the 3 purines IMP, GMP, and adenosine 5'-monophosphate (AMP) lowered the MPG threshold in all participants (P < 0.001), indicating they are positive modulators or enhancers of glutamate taste. The average detection threshold of MPG was 2.08 mM, and with the addition of IMP, the threshold was decreased by approximately 1.5 orders of magnitude to 0.046 mM. In contrast to the purines, the pyrimidines uridine 5'-monophosphate (UMP) and cytidine 5'-monophosphate (CMP) yielded different results. CMP reliably raised glutamate thresholds in 10 of 17 subjects, suggesting it is a negative modulator or diminisher of glutamate taste for them. The rank order of effects on increasing sensitivity to glutamate was IMP > GMP> AMP >> UMP// CMP. These data confirm that ribonucleotides are modulators of glutamate taste, with purines enhancing sensitivity and pyrimidines displaying variable and even negative modulatory effects. Our ability to detect the co-occurrence of glutamate and purines is meaningful as both are relatively high in evolutionarily important sources of nutrition, such as insects and fermented foods.

Changes in physical architecture and lipids compounds in skeletal muscle from Pekin duck and Liancheng white duck

As a complex food, meat displays various biochemical properties that are determined to a great extent by physical architecture and lipid metabolites. Pekin duck and Liancheng white duck are elite breeds with distinct characteristics. Here, we explored the development of the muscle fibers from embryonic stage to 10-wk after birth, and muscle fibers grow slowly after 8-wk. We investigated the meat quality, ultrastructure, lipidomics profiling, and lipids spatial distribution of skeletal muscle at 8 wk. Pekin duck has lower Warner-Bratzler shear force (WBSF) (P < 0.05), high intramuscular fat (IMF) (P < 0.01), longer and wider sarcomere, and higher mitochondrial density (P < 0.001). Liancheng white duck with tighter collagen architecture. A total of 950 lipids from 6 lipid classes identified with lipidomics were analyzed, the levels of GP, GL, and PR were significantly higher in Pekin duck (P < 0.05), SL and ST were significantly higher in Liancheng white duck (P < 0.05). There were 333 significantly different lipids (|log2(Fold Change)| ≥ 1 and FDR < 0.05) screened, most lipids distributed in the muscle tissue were uniform, but some specifically distributed in connective tissue. To some extent, the results demonstrate the high lipid deposition capacity of Pekin duck and the high medicinal function of Liancheng white duck. Our study provides new insights into the relationship between skeletal muscle architecture and meat toughness, which increased the knowledge of lipidomic characteristics and provide a basis for duck meat authentication.

Oral glucose sensing in cephalic phase insulin release

Oral stimulation with foods or food components elicits cephalic phase insulin release (CPIR), which limits postprandial hyperglycemia. Despite its physiological importance, the specific gustatory mechanisms that elicit CPIR have not been clearly defined. While most studies point to glucose and glucose-containing saccharides (e.g., sucrose, maltodextrins) as being the most consistent elicitors, it is not apparent whether this is due to the detection of glucose per se, or to the perceived taste cues associated with these stimuli (e.g., sweetness, starchiness). This study investigated potential sensory mechanisms involved with eliciting CPIR in humans, focusing on the role of oral glucose detection and associated taste. Four stimulus conditions possessing different carbohydrate and taste profiles were designed: 1) glucose alone; 2) glucose mixed with lactisole, a sweet taste inhibitor; 3) maltodextrin, which is digested to starchy- and sweet-tasting products during oral processing; and 4) maltodextrin mixed with lactisole and acarbose, an oral digestion inhibitor. Healthy adults (N = 22) attended four sessions where blood samples were drawn before and after oral stimulation with one of the target stimuli. Plasma c-peptide, insulin, and glucose concentrations were then analyzed. Whereas glucose alone elicited CPIR (one-sample t-test, p < 0.05), it did not stimulate the response in the presence of lactisole. Likewise, maltodextrin alone stimulated CPIR (p < 0.05), but maltodextrin with lactisole and acarbose did not. Together, these findings indicate that glucose is an effective CPIR stimulus, but that an associated taste sensation also serves as an important cue for triggering this response in humans.

Taste assessment for paediatric drug Development: A comparison of bitterness taste aversion in children versus Naïve and expert young adult assessors

Medicines for children often taste bitter, presenting a significant challenge to treatment compliance. However, most studies on paediatric drug development rely on adult volunteers for sensory research, and the level of expertise required from these assessors is unclear. This study aimed to address this gap by investigating perceived bitterness aversion to taste strips impregnated with different concentrations of quinine hydrochloride in 439 school-aged children. Expert (n = 26) and naïve (n = 65) young adult assessors evaluated quinine solutions as well as taste strips, for methodological bridging purposes. All assessors differentiated the aversiveness of the taste strips in a dose dependent manner. Younger children aged 4-8 years had difficulty discriminating higher bitter concentrations, whereas pre-adolescents 9-11 years and naive adults showed better discrimination at the top of the scale. Naive assessors showed similar bitter perception as children. However, the results were slightly different between strips and solution in adults. These findings highlight the key role that adult panels can play in paediatric formulation development. Taste strips show promise as a safe and pragmatic tool for sensory pharmaceutical evaluations, though further studies are warranted to establish the relationship between age and hedonic taste perception using compounds with diverse physicochemical and sensory qualities.

Human subsistence and signatures of selection on chemosensory genes

Chemosensation (olfaction, taste) is essential for detecting and assessing foods, such that dietary shifts elicit evolutionary changes in vertebrate chemosensory genes. The transition from hunting and gathering to agriculture dramatically altered how humans acquire food. Recent genetic and linguistic studies suggest agriculture may have precipitated olfactory degeneration. Here, we explore the effects of subsistence behaviors on olfactory (OR) and taste (TASR) receptor genes among rainforest foragers and neighboring agriculturalists in Africa and Southeast Asia. We analyze 378 functional OR and 26 functional TASR genes in 133 individuals across populations in Uganda (Twa, Sua, BaKiga) and the Philippines (Agta, Mamanwa, Manobo) with differing subsistence histories. We find no evidence of relaxed selection on chemosensory genes in agricultural populations. However, we identify subsistence-related signatures of local adaptation on chemosensory genes within each geographic region. Our results highlight the importance of culture, subsistence economy, and drift in human chemosensory perception.

Ultraprocessed Foods and Obesity Risk: A Critical Review of Reported Mechanisms

Epidemiologic evidence supports a positive association between ultraprocessed food (UPF) consumption and body mass index. This has led to recommendations to avoid UPFs despite very limited evidence establishing causality. Many mechanisms have been proposed, and this review critically aimed to evaluate selected possibilities for specificity, clarity, and consistency related to food choice (i.e., low cost, shelf-life, food packaging, hyperpalatability, and stimulation of hunger/suppression of fullness); food composition (i.e., macronutrients, food texture, added sugar, fat and salt, energy density, low-calorie sweeteners, and additives); and digestive processes (i.e., oral processing/eating rate, gastric emptying time, gastrointestinal transit time, and microbiome). For some purported mechanisms (e.g., fiber content, texture, gastric emptying, and intestinal transit time), data directly contrasting the effects of UPF and non-UPF intake on the indices of appetite, food intake, and adiposity are available and do not support a unique contribution of UPFs. In other instances, data are not available (e.g., microbiome and food additives) or are insufficient (e.g., packaging, food cost, shelf-life, macronutrient intake, and appetite stimulation) to judge the benefits versus the risks of UPF avoidance. There are yet other evoked mechanisms in which the preponderance of evidence indicates ingredients in UPFs actually moderate body weight (e.g., low-calorie sweetener use for weight management; beverage consumption as it dilutes energy density; and higher fat content because it reduces glycemic responses). Because avoidance of UPFs holds potential adverse effects (e.g., reduced diet quality, increased risk of food poisoning, and food wastage), it is imprudent to make recommendations regarding their role in diets before causality and plausible mechanisms have been verified.

Dead rats, dopamine, performance metrics, and peacock tails: Proxy failure is an inherent risk in goal-oriented systems

When a measure becomes a target, it ceases to be a good measure. For example, when standardized test scores in education become targets, teachers may start "teaching to the test," leading to breakdown of the relationship between the measure - test performance - and the underlying goal - quality education. Similar phenomena have been named and described across a broad range of contexts, such as economics, academia, machine learning, and ecology. Yet it remains unclear whether these phenomena bear only superficial similarities, or if they derive from some fundamental unifying mechanism. Here, we propose such a unifying mechanism, which we label proxy failure. We first review illustrative examples and their labels, such as the "cobra effect," "Goodhart's law," and "Campbell's law." Second, we identify central prerequisites and constraints of proxy failure, noting that it is often only a partial failure or divergence. We argue that whenever incentivization or selection is based on an imperfect proxy measure of the underlying goal, a pressure arises that tends to make the proxy a worse approximation of the goal. Third, we develop this perspective for three concrete contexts, namely neuroscience, economics, and ecology, highlighting similarities and differences. Fourth, we outline consequences of proxy failure, suggesting it is key to understanding the structure and evolution of goal-oriented systems. Our account draws on a broad range of disciplines, but we can only scratch the surface within each. We thus hope the present account elicits a collaborative enterprise, entailing both critical discussion as well as extensions in contexts we have missed.

Food System Transformation and Gut Microbiota Transition: Evidence on Advancing Obesity, Cardiovascular Diseases, and Cancers-A Narrative Review

Food, a vital component of our daily life, is fundamental to our health and well-being, and the knowledge and practices relating to food have been passed down from countless generations of ancestors. Systems may be used to describe this extremely extensive and varied body of agricultural and gastronomic knowledge that has been gathered via evolutionary processes. The gut microbiota also underwent changes as the food system did, and these alterations had a variety of effects on human health. In recent decades, the gut microbiome has gained attention due to its health benefits as well as its pathological effects on human health. Many studies have shown that a person's gut microbiota partially determines the nutritional value of food and that diet, in turn, shapes both the microbiota and the microbiome. The current narrative review aims to explain how changes in the food system over time affect the makeup and evolution of the gut microbiota, advancing obesity, cardiovascular disease (CVD), and cancer. After a brief discussion of the food system's variety and the gut microbiota's functions, we concentrate on the relationship between the evolution of food system transformation and gut microbiota system transition linked to the increase of non-communicable diseases (NCDs). Finally, we also describe sustainable food system transformation strategies to ensure healthy microbiota composition recovery and maintain the host gut barrier and immune functions to reverse advancing NCDs.

Metabolome-Based Genome-Wide Association Study of Duck Meat Leads to Novel Genetic and Biochemical Insights

Meat is among the most consumed foods worldwide and has a unique flavor and high nutrient density in the human diet. However, the genetic and biochemical bases of meat nutrition and flavor are poorly understood. Here, 3431 metabolites and 702 volatiles in 423 skeletal muscle samples are profiled from a gradient consanguinity segregating population generated by Pekin duck × Liancheng duck crosses using metabolomic approaches. The authors identified 2862 metabolome-based genome-wide association studies (mGWAS) signals and 48 candidate genes potentially modulating metabolite and volatile levels, 79.2% of which are regulated by cis-regulatory elements. The level of plasmalogen is significantly associated with TMEM189 encoding plasmanylethanolamine desaturase 1. The levels of 2-pyrrolidone and glycerophospholipids are regulated by the gene expression of AOX1 and ACBD5, which further affects the levels of volatiles, 2-pyrrolidone and decanal, respectively. Genetic variations in GADL1 and CARNMT2 determine the levels of 49 metabolites including L-carnosine and anserine. This study provides novel insights into the genetic and biochemical basis of skeletal muscle metabolism and constitutes a valuable resource for the precise improvement of meat nutrition and flavor.

Testing conditionality with Bourdieu's capital theory: How economic, social, and embodied cultural capital are associated with diet and physical activity in the Netherlands

Although Bourdieu's capital theory emphasized that economic, social, and embodied cultural capital interact to shape health behavior, existing empirical research mainly considered separate associations of the three forms of capital. Our aim was to investigate if and how economic, social, and embodied cultural capital are conditional on each other in their associations with adults' diet and physical activity. Cross-sectional, self-reported data from the 2014 GLOBE survey of 2812 adults aged between 25 and 75 years residing in Eindhoven, the Netherlands were used. Step-wise multiple logistic regression models included economic, social, and embodied cultural capital and adjustment for potential confounders. The models estimated odds ratios of main effects and two-way interactions of the forms of capital with fruit consumption, vegetable consumption, sports participation, and leisure time walking or cycling. In the main effects models, embodied cultural capital was consistently positively associated with all outcomes. Social capital was positively associated with sports participation, fruit consumption, and vegetable consumption, and economic capital was positively associated with sports participation and vegetable consumption. In the two-way interaction models, having specific higher levels of both economic and social capital strengthened their positive association with sports participation. No other combinations of capital were conditional on each other. Economic and social capital were conditional on each other in their association with sports participation, so interventions that provide both economic and social support may be especially effective for increasing this type of physical activity. As its association was strong with all outcomes but not conditional on other forms of capital, embodied cultural capital may operate distinctly from economic and social resources. Policy that takes differences in embodied cultural capital into account or changes to the environment that dampen the importance of embodied cultural resources for health behavior may help improve both diet and physical activity.

Effects of weight change on taste function; a systematic review

BACKGROUND

The aim of this review is to evaluate the relationship between weight status and taste perception and preference of sweet, salt, fat, bitter, and sour through reviewing observational and interventional studies with objective methods.

METHODS

A comprehensive literature search was performed in 6 online databases of PubMed, Scopus, Web of Science, Cochrane, Embase, and Google Scholar up to October 2021. The following keywords were used in the search strategy: (Taste OR "Taste Perception" OR "Taste Threshold" OR "Taste preference" OR "Taste sensitivity" OR "Taste changes") AND (weight OR "Weight gain" OR "weight loss" OR "weight change").

RESULTS

Most observational studies indicate that four taste sensitivities or perceptions (especially sweet and salt taste perception) are lower in subjects with overweight and obesity. The longitudinal studies reported that sweet and fat preference is increased along with weight gain in adults. It is concluded that taste perceptions are decreased in individuals with overweight and obesity, especially in men. Also, taste perception and preference change after weight loss but not significantly.

CONCLUSION

It is suggested that the results of the interventional studies are not conclusive and need further studies with the same and standard design adjusting cofounding variables including genetic, gender, age and food condition of subjects.

Human nutritional intelligence underestimated? Exposing sensitivities to food composition in everyday dietary decisions

The social and cultural significance of food is woven into every aspect of our dietary behaviour, and it contributes to our complex interaction with food. To find order within this complexity scientists often look for dietary 'universals' - phenomena or basic principles that guide our food choice and meal size, irrespective of wider context. One such idea is that taste characteristics provide a signal for dietary composition (e.g., sweet taste signals carbohydrate). Others have suggested that behaviour is guided by learning and is based on associations that form between the flavour of a food and its post-ingestive effects. Despite a large body of research, evidence supporting both processes is equivocal, leading some to conclude that humans are largely indifferent to food composition. Here, we argue that human abilities to gauge the nutritional composition or value of food have been underestimated, and that they can be exposed by embracing alternative methods, including cross-cultural comparisons, large nutrition surveys, and the use of virtual portion-selection tools. Our group has focused on assessments of food choice and expected satiety, and how comparisons across everyday foods can reveal non-linear relationships with food energy density, and even the potential for sensitivity to micronutrient composition. We suggest that these abilities might reflect a complex form of social learning, in which flavour-nutrient associations are not only formed but communicated and amplified across individuals in the form of a cuisine. Thus, rather than disregarding sociocultural influences as extraneous, we might reimagine their role as central to a process that creates and imbues a 'collective dietary wisdom.' In turn, this raises questions about whether rapid dietary, technological, and cultural change disrupts a fundamental process, such that it no longer guarantees a 'nutritional intelligence' that confers benefits for health.

Alteration of taste perception, food neophobia and oral microbiota composition in children with food allergy

Currently, the mechanisms underlying sensory perception and sensory performance in children with food allergies are far from being understood. As well, only recently, single research afforded the oral host-commensal milieu, addressing oral microbial communities in children with peanut allergies. To bridge the current gaps in knowledge both in the sensory and microbial fields, a psychophysiological case-control study was performed in allergic children (n = 29) and a healthy sex-age-matched control group (n = 30). Taste perception, food neophobia, and liking were compared in allergic and non-allergic children. The same subjects were characterized for their oral microbiota composition by addressing saliva to assess whether specific profiles were associated with the loss of oral tolerance in children with food allergies. Our study evidenced an impaired ability to correctly identify taste qualities in the allergic group compared to controls. These results were also consistent with anatomical data related to the fungiform papillae on the tongue, which are lower in number in the allergic group. Furthermore, distinct oral microbial profiles were associated with allergic disease, with significant down-representations of the phylum Firmicutes and of the genera Veillonella spp., Streptococcus spp., Prevotella spp., and Neisseria spp. For the first time, this study emphasizes the link between sensory perception and food allergy, which is a novel and whole-organism view of this pathology. Our data indicated that an impaired taste perception, as regards both functionality and physiologically, was associated with food allergy, which marginally influences the food neophobia attitude. It is also accompanied by compositional shifts in oral microbiota, which is, in turn, another actor of this complex interplay and is deeply interconnected with mucosal immunity. This multidisciplinary research will likely open exciting new approaches to therapeutic interventions.

Highly processed foods can be considered addictive substances based on established scientific criteria

BACKGROUND

There is growing evidence that an addictive-eating phenotype may exist. There is significant debate regarding whether highly processed foods (HPFs; foods with refined carbohydrates and/or added fats) are addictive. The lack of scientifically grounded criteria to evaluate the addictive nature of HPFs has hindered the resolution of this debate.

ANALYSIS

The most recent scientific debate regarding a substance's addictive potential centered around tobacco. In 1988, the Surgeon General issued a report identifying tobacco products as addictive based on three primary scientific criteria: their ability to (1) cause highly controlled or compulsive use, (2) cause psychoactive (i.e. mood-altering) effects via their effect on the brain and (3) reinforce behavior. Scientific advances have now identified the ability of tobacco products to (4) trigger strong urges or craving as another important indicator of addictive potential. Here, we propose that these four criteria provide scientifically valid benchmarks that can be used to evaluate the addictiveness of HPFs. Then, we review the evidence regarding whether HPFs meet each criterion. Finally, we consider the implications of labeling HPFs as addictive.

CONCLUSION

Highly processed foods (HPFs) can meet the criteria to be labeled as addictive substances using the standards set for tobacco products. The addictive potential of HPFs may be a key factor contributing to the high public health costs associated with a food environment dominated by cheap, accessible and heavily marketed HPFs.

Sensory emotion regulation

Decades of evidence reveal intimate links between sensation and emotion. Yet, discussion of sensory experiences as tools that promote emotion regulation is largely absent from current theorizing on this topic. Here, we address this gap by integrating evidence from social-personality, clinical, cognitive-neuroscience, and animal research to highlight the role of sensation as a tool that can be harnessed to up- or downregulate emotion. Further, we review evidence implicating sensation as a rapid and relatively effortless emotion regulation modality and highlight future research directions. Notably, we emphasize the need to examine the duration of sensory emotion regulation effects, the moderating role of individual and cultural differences, and how sensory strategies interact with other strategies.

Nutrigenomics in the context of evolution

Nutrigenomics describes the interaction between nutrients and our genome. Since the origin of our species most of these nutrient-gene communication pathways have not changed. However, our genome experienced over the past 50,000 years a number of evolutionary pressures, which are based on the migration to new environments concerning geography and climate, the transition from hunter-gatherers to farmers including the zoonotic transfer of many pathogenic microbes and the rather recent change of societies to a preferentially sedentary lifestyle and the dominance of Western diet. Human populations responded to these challenges not only by specific anthropometric adaptations, such as skin color and body stature, but also through diversity in dietary intake and different resistance to complex diseases like the metabolic syndrome, cancer and immune disorders. The genetic basis of this adaptation process has been investigated by whole genome genotyping and sequencing including that of DNA extracted from ancient bones. In addition to genomic changes, also the programming of epigenomes in pre- and postnatal phases of life has an important contribution to the response to environmental changes. Thus, insight into the variation of our (epi)genome in the context of our individual's risk for developing complex diseases, helps to understand the evolutionary basis how and why we become ill. This review will discuss the relation of diet, modern environment and our (epi)genome including aspects of redox biology. This has numerous implications for the interpretation of the risks for disease and their prevention.

Processing of Sweet, Astringent and Pungent Oral Stimuli in the Human Brain

Taste and oral somatosensation are intimately related to each other from peripheral receptors to the central nervous system. Oral astringent sensation is thought to contain both gustatory and somatosensory components. In the present study, we compared the cerebral response to an astringent stimulus (tannin), with the response to one typical taste stimulus (sweet - sucrose) and one typical somatosensory stimulus (pungent - capsaicin) using functional magnetic resonance imaging (fMRI) of 24 healthy subjects. Three distributed brain sub-regions responded significantly different to the three types of oral stimulations: lobule IX of the cerebellar hemisphere, right dorsolateral superior frontal gyrus, and left middle temporal gyrus. This suggests that these regions play a major role in the discrimination of astringency, taste, and pungency.