A new method for delivering a taste without fluids to preterm and term infants

Effect of sweetened beverages intake on salivary aspartame, insulin and alpha-amylase levels: A single-blind study

The objective was to assess aspartame excretion in saliva and the salivary insulin, total protein (TP), and alpha-amylase (AMI) levels in response to the ingestion of sweetened beverages (sodium cyclamate, aspartame, acesulfame, and sucrose). Fifteen healthy participants were included in a single-blinded trial with the intake of Diet soft drink, Regular soft drink, Water + sweeteners, Low sucrose content (3.5 g), and Water (blank) in 5 different days. In each day, saliva was collected at T0 (fasting), T1 (15 min after test-drink intake), T2 (30 min), T3 (60 min), and T4 (120 min) for the measurement of salivary aspartame (HPLC), TP, AMI (ELISA assays) and insulin levels (chemiluminescence). Chi-square, Friedman, ANOVA and Spearman correlation tests were applied. The late-perceived sweet/sour residual flavor was reported at a frequency of 80%, 60% and 20% after ingestion of artificially sweetened drinks, beverages with sucrose, and plain water, respectively (p < 0.05). Aspartame was detected in saliva after artificially sweetened drinks intake, with highest area under the peak for the Diet soft drink (p = 0.014). No change was observed for TP and AMI levels during the 120 min. Insulin levels increased 1 h after soft-drinks ingestion (regular and diet), while the levels did not change for Low sucrose content and Water + sweeteners test-drinks. Salivary aspartame correlated with insulin levels only after Diet soft drink intake (rho ≥ 0.7; p < 0.05). As aspartame can be detected in saliva and swallowed again until completely excreted, these results contribute to the knowledge of the biological fate of artificial sweeteners and the study of health outcomes.

Flavor Sensing in Utero and Emerging Discriminative Behaviors in the Human Fetus

The diet of pregnant women exposes fetuses to a variety of flavors consisting of compound sensations involving smell, taste, and chemesthesis. The effects of such prenatal flavor exposure on chemosensory development have so far been measured only postnatally in human infants. Here, we report the first direct evidence of human fetal responsiveness to flavors transferred via maternal consumption of a single-dose capsule by measuring frame-by-frame fetal facial movements. Pregnant women and their fetuses based in the northeast of England were involved in this study from 32 to 36 weeks' gestation. Fetuses exposed to carrot flavor (n = 35) showed "lip-corner puller" and "laughter-face gestalt" more frequently, whereas fetuses exposed to kale flavor (n = 34) showed more "upper-lip raiser," "lower-lip depressor," "lip stretch," "lip presser," and "cry-face gestalt" in comparison with the carrot group and a control group not exposed to any flavors (n = 30). The complexity of facial gestalts increased from 32 to 36 weeks in the kale condition, but not in the carrot condition. Findings of this study have important implications for understanding the earliest evidence for fetal abilities to sense and discriminate different flavors.

Umami and Other Taste Perceptions in Patients With Parkinson's Disease

Objective

Studies of taste perceptions in Parkinson’s disease (PD) patients have been controversial, and none of these studies have assessed umami taste. This study aimed to assess umami, along with the other 4 taste functions in PD patients.

Methods

Participants were tested for gustation using the modified filter paper disc method and olfaction using the modified Sniffin’ Stick-16 (mSS-16) test (only 14 culturally suitable items were used). A questionnaire evaluated patients’ subjective olfactory and gustatory dysfunction, taste preference, appetite, and food habits.

Results

A total of 105 PD patients and 101 age- and sex-matched controls were included. The body mass index (BMI) of PD patients was lower than that of controls (PD = 22.62, controls = 23.86, p = 0.028). The mSS-16 score was 10.7 for controls and 6.4 for PD patients (p < 0.001) (normal ≥ 9). Taste recognition thresholds (RTs) for sweet, salty, sour, bitter and umami tastes were significantly higher in PD, indicating poorer gustation. All taste RTs correlated with each other, except for umami. Most patients were unaware of their dysfunction. Patients preferred sweet, salty and umami tastes more than the controls. Dysgeusia of different tastes in patients was differentially associated with poorer discrimination of tastes, an inability to identify the dish and adding extra seasoning to food. BMI and mSS-16 scores showed no correlation in either patients or controls.

Conclusion

PD patients have dysgeusia for all five tastes, including umami, which affects their appetite and diet. Patients preferred sweet, salty and umami tastes. This information can help adjust patients’ diets to improve their nutritional status.

Influence of taste stimulation on sucking pressure in newborn infants at term

PURPOSE

To verify the influence of a taste stimulus on the suction pressure, during the non-nutritive sucking (SNN), in newborns, healthy and with weight appropriate to the gestational age.

METHODS

Quasi-experimental study of the non-randomized clinical trial type with a convenience sample of 60 newborns (NB), 30 allocated in the study group (EG) and 30 in the control group (CG). The NB were evaluated for sucking pressure during the SNN in a pacifier. For the EG, a gustatory stimulus was added to the pacifier, moistened with colostrum. The CG did not receive any stimulus, other than the pacifier itself. The average, minimum and maximum pressures were measured with the equipment S-Flex®.

RESULTS

The SG presented mean and maximum sucking pressure significantly higher than the CG. In addition, there was a statistically significant difference between the groups for the second measurement of mean sucking pressure.

CONCLUSION

The results showed that the NB of the SG presented sucking pressures, average and maximum, significantly higher, when compared to the CG. The use of a taste stimulus associated with SNN modified the sucking pressure and seems to enhance oral skills.

Finding the Sweet Spot: Measurement, Modification, and Application of Sweet Hedonics in Humans

Sweetness is a sensation that contributes to the palatability of foods, which is the primary driver of food choice. Thus, understanding how to measure the appeal (hedonics) of sweetness and how to modify it are key to effecting dietary change for health. Sweet hedonics is multidimensional so can only be captured by multiple approaches including assessment of elements such as liking, preference, and consumption intent. There are both innate and learned components to the appeal of sweet foods and beverages. These are responsive to various behavioral and biological factors, suggesting the opportunity to modify intake. Given the high amount of added sugar intake in the United States and recommendations from many groups to reduce this, further exploration of current hypothesized approaches to moderate sugar intake (e.g., induced hedonic shift, use of low-calorie sweeteners) is warranted.

Female sweet-likers have enhanced cross-modal interoceptive abilities

There are well known phenotypic differences in sweet-liking across individuals, but it remains unknown whether these are related to broader underlying differences in interoceptive abilities (abilities to sense the internal state of the body). Here, healthy women (N = 64) classified as sweet likers (SLs) or sweet dislikers (SDs) completed a bimodal interoception protocol. A heartbeat tracking and a heartbeat discrimination task determined cardiac interoception; both were accompanied by confidence ratings. A water load task, where participants consumed water to satiation and then to maximum fullness was used to assess gastric interoceptive abilities. Motivational state, psychometric characteristics and eating behaviour were also assessed. SLs performed significantly better than SDs on both heartbeat tasks, independently of impulsivity, anxiety, depression, and alexithymia. No differences in metacognitive awareness and subjective interoceptive measures were found. With gastric interoception, SLs were more sensitive to stomach distention, and they ingested less water than SDs to reach satiety when accounting for stomach capacity. SLs also scored higher on mindful and intuitive eating scales and on emotional eating particularly in response to negative stimuli; emotional overeating was fully mediated via interoceptive performance. Overall, our data suggest the SL phenotype may reflect enhanced responsiveness to internal cues more broadly.

Effect of Added Sugar on the Consumption of A Lipid-Based Nutrient Supplement Among 7-24-Month-Old Children

Small-quantity lipid-based nutrient supplements (SQ-LNS) could help prevent malnutrition. Our primary objective was to examine the acceptability and consumption of sweetened and unsweetened versions of SQ-LNS before and after 14-days of repeated exposure. A total of 78 mother-infant dyads recruited from health centers in Morelos, Mexico, were randomized to two groups of SQ-LNS (sweetened, LNS-S; unsweetened, LNS-U). During the study, infants were fed SQ-LNS (20 g) mixed with 30 g of complementary food of the caregiver’s choice. The amount of supplement-food mixture consumed was measured before, during and after a 14-day home exposure period. We defined acceptability as consumption of at least 50% of the offered food mixture. At initial exposure, LNS-U consumption was on average 44.0% (95% CI: 31.4, 58.5) and LNS-S 34.8% (25.3, 44.0); at final exposure, LNS-U and LNS-S consumption were 38.5% (27.8, 54.0) and 31.5% (21.6, 43.0). The average change in consumption did not differ between the groups (2.2 p.p. (−17.2, 24.4)). We conclude that the acceptability of sweetened and unsweetened SQ-LNS was low in this study population. Since consumption did not differ between supplement versions, we encourage the use of the unsweetened version given the potential effects that added sugar may have on weight gain especially in regions facing the double burden of malnutrition.

A new look at early exposure to the flavors of the available vegetables as foundational mechanism of vegetable consumption habits and recipes of vegetables-based dishes

The flavor of the maternal diet is transferred to women's amniotic fluid and breast milk, so that the amniotic fluid and breast milk become natural transmitters of flavor-related information developing babies are exposed to at early stages of development. We aimed to review the available evidence regarding the impact of early exposure to flavor on child vegetable intake, and to discuss for the first time possible effects of availability or unavailability of particular vegetables because of geographic reasons on these exposures, a variable that has been forgotten in the literature. We have focused on studies that have examined the association of prenatal and early postnatal -at breastfeeding- exposures to vegetable-related flavors with vegetable consumption in children. We have identified that this particular kind of exposures may lead to increases in children's acceptance, liking of and preference for the vegetables. Especially novel has been to identify that these effects might be modulated not only by the particular flavor of the vegetable -bitter vs. sweet- and the time of exposure -prenatal vs. breastfeeding- but also by vegetable availability because of geographic reasons of the place of residence of the mother, a variable that should be taken into account in future research. This would give rise to a new research line aimed at solving the mentioned gap. Finally, a theoretical model of cyclical processes that might explain the origin and perpetuation of transmission of particular patterns of vegetable consumption and vegetables-composed dishes over time in a given population is also included here as another new contribution.

Sucrose and saccharin differentially modulate depression and anxiety-like behavior in diabetic mice: exposures and withdrawal effects

RATIONALE

Sugar has addictive potential owing to increase in monoaminergic-transmission at pleasure and reward centers of brain. Insulin dysfunction triggered synaptic monoamine deficit is associated with sugar overeating and craving-related psychological changes in diabetic patients. Sugar-substitute (saccharin) is non-caloric artificial sweetener that may alleviate brain disorders in diabetes.

OBJECTIVES

In present study, effects of sucrose and sugar-substitute (saccharin) exposures and withdrawal on depression and anxiety-like behavior in type 2 diabetic mice were assessed.

METHODS

Swiss albino mice were injected with streptozotocin (135 mg/kg). After induction of diabetes, mice were exposed to a two-bottle water-water, 10% sucrose-water, or 10% saccharin-water choice paradigm for 28 days. Separate groups were employed to assess withdrawal effect of sucrose or saccharin in diabetic mice. Monoamine oxidase (MAO), corticosterone, thiobarbituric acid reactive substances (TBARS), and reduced glutathione (GSH) were quantified after behavioral tests.

RESULTS

Diabetic mice manifested preference towards 10% sucrose or saccharin over water. Sucrose-overeating by diabetic mice amplified symptoms of depression and anxiety; however, withdrawal further exaggerated these behavioral abnormalities. Substitution of sucrose by 10% saccharin attenuated the depressive and anxiety-like behavior in comparison to diabetic mice that were exposed separately to water-water or sucrose-water alone, and with respect to normal mice. Although withdrawal from saccharin resurfaced behavioral anomalies in diabetic mice, however, these were significantly low in comparison with withdrawal from sucrose or normal group. Reinstatement of exposure to saccharin mitigated symptoms of depression and anxiety in diabetic mice.

CONCLUSION

Preference of sucrose overeating augments while saccharin mitigates depressive and anxiety behavior during diabetes.

Effects of consuming sugars and alternative sweeteners during pregnancy on maternal and child health: evidence for a secondhand sugar effect

Consumption of sugar and alternative low- or no-energy sweeteners has increased in recent decades. However, it is still uncertain how consumption of sugar and alternative sweeteners during pregnancy affects pregnancy outcomes and long-term offspring health. This review aims to collate the available evidence surrounding the consequences of sugar and alternative sweetener consumption during pregnancy, a so-called secondhand sugar effect. We found evidence that sugar consumption during pregnancy may contribute to increased gestational weight gain and the development of pregnancy complications, including gestational diabetes, preeclampsia and preterm birth. Further, we found a growing body of the animal and human evidence that maternal sugar intake during pregnancy may impact neonatal and childhood metabolism, taste perception and obesity risk. Emerging evidence also suggests that both maternal and paternal preconception sugar intakes are linked to offspring metabolic outcomes, perhaps via epigenetic alterations to the germline. While there have been fewer studies of the impacts of alternative sweetener consumption before and during pregnancy, there is some evidence to suggest effects on infant outcomes including preterm birth risk, increased infant body composition and offspring preference for sweet foods, although mechanisms are unclear. We conclude that preconception and gestational sugar and alternative sweetener consumption may negatively impact pregnancy outcomes and offspring health and that there is a need for further observational, mechanistic and intervention research in this area.

From biology to behavior: a cross-disciplinary seminar series surrounding added sugar and low-calorie sweetener consumption

INTRODUCTION

This report presents a synopsis of a three-part, cross-sector, seminar series held at the George Washington University (GWU) in Washington, DC from February-April, 2018. The overarching goal of the seminar series was to provide a neutral forum for diverse stakeholders to discuss and critically evaluate approaches to address added sugar intake, with a key focus on the role of low-calorie sweeteners (LCS).

METHODS

During three seminars, twelve speakers from academic institutions, federal agencies, non-profit organizations, and the food and beverage industries participated in six interactive panel discussions to address: 1) Do Farm Bill Policies Impact Population Sugar Intake? 2) What is the Impact of Sugar-sweetened Beverage (SSB) Taxes on Health and Business? 3) Is Sugar Addictive? 4) Product Reformulation Efforts: Progress, Challenges, and Concerns? 5) Low-calorie Sweeteners: Helpful or Harmful, and 6) Are Novel Sweeteners a Plausible Solution? Discussion of each topic involved brief 15-minute presentations from the speakers, which were followed by a 25-minute panel discussion moderated by GWU faculty members and addressed questions generated by the audience. Sessions were designed to represent opposing views and stimulate meaningful debate. Given the provocative nature of the seminar series, attendee questions were gathered anonymously using Pigeonhole™, an interactive, online, question and answer platform.

RESULTS

This report summarizes each presentation and recapitulates key perspectives offered by the speakers and moderators.

CONCLUSIONS

The seminar series set the foundation for robust cross-sector dialogue necessary to inform meaningful future research, and ultimately, effective policies for lowering added sugar intakes.

Exposure to a slightly sweet lipid-based nutrient supplement during early life does not increase the level of sweet taste most preferred among 4- to 6-year-old Ghanaian children: follow-up of a randomized controlled trial

BACKGROUND

The impact of feeding a slightly sweet nutrient supplement early in life on later sweet taste preference is unknown.

OBJECTIVE

We tested the hypothesis that the level of sucrose most preferred by 4-6-y-old children exposed to a slightly sweet lipid-based nutrient supplement (LNS) early in life would not be higher than that of children never exposed to LNS.

DESIGN

We followed up children born to women (n = 1,320) who participated in a randomized trial in Ghana. In one group, LNS was provided to women on a daily basis during pregnancy and the first 6 mo postpartum and to their infants from age 6 to 18 mo (LNS group). The control groups received daily iron and folic acid or multiple micronutrients during pregnancy and the first 6 mo postpartum, with no infant supplementation (non-LNS group). At age 4-6 y, we randomly selected a subsample of children (n = 775) to assess the concentration of sucrose most preferred using the Monell 2-series, forced-choice, paired-comparison tracking procedure. We compared LNS with non-LNS group differences using a noninferiority margin of 5% weight/volume (wt/vol).

RESULTS

Of the 624 children tested, most (61%) provided reliable responses. Among all children, the mean ± SD sucrose solution most preferred (% wt/vol) was 14.6 ± 8.6 (LNS group 14.9 ± 8.7; non-LNS group 14.2 ± 8.4). However, among children with reliable responses, it was 17.0 ± 10.2 (LNS group 17.5 ± 10.4; non-LNS group 16.5 ± 10.0). The upper level of the 95% CI of the difference between groups did not exceed the noninferiority margin in either the full sample or those with reliable responses, indicating that the LNS group did not have a higher sweet preference than the non-LNS group.

CONCLUSION

Exposure to a slightly sweet nutrient supplement early in life did not increase the level of sweet taste most preferred during childhood. This trial was registered at clinicaltrials.gov as NCT00970866.

Oral sensations and secretions

Sensations experienced in the mouth influence food choices, both immediately and in the long term. Such sensations are themselves influenced by experience with flavors, the chemical environment of the mouth, genetics of receptors for flavors, and individual behavior in the chewing of food. Gustation, the sense of taste, yields information about nutrients, influences palatability, and feeds into the human body's preparation to receive those nutrients. Olfaction, the sense of smell, contributes enormously to defining and identifying food flavors (and is experienced even after placing food inside the mouth). Another vital component of food flavor is texture, which contributes to palatability, especially if a food's texture violates a person's expectations. Next, chemesthesis is the sense of chemically induced irritancy and temperature, for example spiciness and stinging. All of these sensations are potentially modified by saliva, the chemical and physical media of the mouth. As a person experiences the culmination of these oral sensations, modified through an individual's own unique saliva, the flavors in turn influence both what and how a person eats.

Nutrition and taste and smell dysfunction

Food selection plays a pivotal role in maintaining adequate nutrient intake, thus elucidating drivers of food choice is a meaningful strategy to maintain health and manage disease. Taste and smell are key determinants of food choice and warrant careful consideration. In this review, we first discuss how sensory stimulation influences food selection and metabolism. We then review the evidence regarding the relationship between taste and smell dysfunction and food preferences and selection, with attention given to contexts of certain chronic diseases. We conclude with brief recommendations for the management of chemosensory disorders. While sensory abilities influence food selection, the effect of taste and smell dysfunction on long-term consumption patterns and health status must be considered in light of environment, exposure, and culture.

Taste-Elicited Activity in Facial Muscle Regions in 5-8-Week-Old Infants

The state of development of the sense of taste in humans during the first few months of life is only partially understood. Since taste plays a critical role in the feeding and nutrition of infants a better understanding of taste development during early life is required. Currently, information about the sense of taste in pre-verbal infants is obtained by analysis of videotaped facial expressions using the Baby FACS coding system. A potentially more objective faster procedure for assessing facial expressions not investigated in infants is electromyography (EMG). The method has been successfully used to study taste-elicited responses in the mid-face muscle regions of the levator labii and zygomaticus major of 6-9-year-olds and in a range of facial muscle regions in adults. Accordingly, this study aimed to investigate taste in young infants using EMG to 1) measure activity simultaneously in 4 facial muscle regions in response to 3 common tastants and 2) determine whether the activities of one or more muscle regions is needed to provide evidence of perception of a tastant by an infant. The results indicated that multiple facial muscle regions responded simultaneously but differentially to non-sweet and sweet tastants and recordings of activities from 3 or 4 regions simultaneously indicated that almost 100% of infants responded to the unpleasant tastes of quinine and citric acid, and 80% to sucrose.

The Relationship between Infant Facial Expressions and Food Acceptance

PURPOSE OF REVIEW

To highlight the range of methodological approaches used to objectively measure hedonic responses to taste stimuli during the first year of life and how these behavioral responses change with experience. Challenges inherent to this type of research are discussed.

RECENT FINDINGS

Although newborns display characteristic orofacial reactivity to four of the five basic tastes, the facial expressions made and the amount of food consumed can be modified by experience: children learn to like what they are fed. In some cases changes in facial responses are concordant with infant consumption, whereas in other cases facial reactivity follows changes in intake.

SUMMARY

Together with ingestive measurements, precise and objective measurements of orofacial reactivity provide an understanding of how early experiences shift the hedonic tone of the taste of foods, the foundation of dietary preferences.

The development of sweet taste: From biology to hedonics

From the age of 2 years, an American child is more likely to consume a sugar-sweetened product than a fruit or vegetable on any given day-a troubling statistic, given that food preferences are established early in childhood, as well as the strong association between this dietary pattern and increased risk of developing a number of chronic diseases. Here, we review the ontogeny and biopsychology of sweet taste, highlighting how a biological drive to prefer sweetness at high concentrations during childhood, which would have conferred an advantage in environments of scarcity, now predisposes children to overconsume all that is sweet in a modern food system replete with added sugars. We review the power of sweet taste to blunt expressions of pain and mask bad tastes in foods as well as factors that predispose some to consume high-sugar diets, including experiential learning and taste preferences driven in part by genetics. Understanding children's unique vulnerability to our current food environment, rich in both nutritive and nonnutritive sweeteners, is highlighted as a priority for future research to develop evidence-based strategies to help establish healthy dietary behaviors early in life.

The sweetness and bitterness of childhood: Insights from basic research on taste preferences

In this article, we review findings from basic, experimental research on children that suggest that the liking of sweet and the dislike of bitter tastes reflect children's basic biology. Children are born preferring sweet tastes, which attract them to mother's milk and even act as an analgesic. They prefer higher levels of sweet than do adults, with preferences declining to adult levels during middle to late adolescence, which coincides with the cessation of physical growth. The level of sweetness most preferred by children has remained heightened relative to adults for nearly a decade, despite reductions in sugar, both consumed and in the food environment. In spite of these reductions, however, children's intake of sugar remains higher than that recommended by health organizations worldwide. In contrast to sweet taste, children dislike and reject bitter taste, which protects them from ingesting poisons. Although variation in bitter taste receptor genes such as TAS2R38 accounts for people's marked differences in perceptions of the same bitter-tasting compounds, basic research revealed that these genotype-phenotype relationships are modified with age, with children of the same genotype being more bitter sensitive than adults and the changeover occurring during mid-adolescence. This heightened bitter sensitivity is also evident in the taste of the foods (green vegetables) or medicines (liquid formulations of drugs) they dislike and reject. While bitter taste can be masked or blocked to varying degrees by sugars and salts, their efficacy in modulating bitterness is not only based on the type of bitter ligand but on the person's age. Children's heightened preference for sweet and dislike of bitter, though often detrimental in the modern food environment, reflects their basic biology. Increasing knowledge of individual variation in taste due to both age and genetics will shed light on potential strategies to promote healthier eating since chronic diseases derive in large part from poor food choice dictated by taste preferences, and will contribute to a new era of drug formulations designed especially for the taste palate of children.

Ontogeny of taste preferences: basic biology and implications for health

Health initiatives address childhood obesity in part by encouraging good nutrition early in life. This review highlights the science that shows that children naturally prefer higher levels of sweet and salty tastes and reject lower levels of bitter tastes than do adults. Thus, their basic biology does not predispose them to favor the recommended low-sugar, low-sodium, vegetable-rich diets and makes them especially vulnerable to our current food environment of foods high in salt and refined sugars. The good news is that sensory experiences, beginning early in life, can shape preferences. Mothers who consume diets rich in healthy foods can get children off to a good start because flavors are transmitted from the maternal diet to amniotic fluid and mother's milk, and breastfed infants are more accepting of these flavors. In contrast, infants fed formula learn to prefer its unique flavor profile and may have more difficulty initially accepting flavors not found in formula, such as those of fruit and vegetables. Regardless of early feeding mode, infants can learn through repeated exposure and dietary variety if caregivers focus on the child's willingness to consume a food and not just the facial expressions made during feeding. In addition, providing complementary foods low in salt and sugars may help protect the developing child from excess intake later in life. Early-life experiences with healthy tastes and flavors may go a long way toward promoting healthy eating, which could have a significant impact in addressing the many chronic illnesses associated with poor food choice.

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.

The bad taste of medicines: overview of basic research on bitter taste

BACKGROUND

Many active pharmaceutical ingredients taste bitter and thus are aversive to children as well as many adults. Encapsulation of the medicine in pill or tablet form, an effective method for adults to avoid the unpleasant taste, is problematic for children. Many children cannot or will not swallow solid dose forms.

OBJECTIVE

This review highlights basic principles of gustatory function, with a special focus on the science of bitter taste, derived from studies of animal models and human psychophysics. We focus on the set of genes that encode the proteins that function as bitter receptors as well as the cascade of events that leads to multidimensional aspects of taste function, highlighting the role that animal models played in these discoveries. We also summarize psychophysical approaches to studying bitter taste in adult and pediatric populations, highlighting evidence of the similarities and differences in bitter taste perception and acceptance between adults and children and drawing on useful strategies from animal models.

RESULTS

Medicine often tastes bitter, and because children are more bitter-sensitive than are adults, this creates problems with compliance. Bitter arises from stimulating receptors in taste receptor cells, with signals processed in the taste bud and relayed to the brain. However, there are many gaps in our understanding of how best to measure bitterness and how to ameliorate it, including whether it is more efficiently addressed at the level of receptor and sensory signaling, at the level of central processing, or by masking techniques. All methods of measuring responsiveness to bitter ligands-in animal models through human psychophysics or with "electronic tongues"-have limitations.

CONCLUSIONS

Better-tasting medications may enhance pediatric adherence to drug therapy. Sugars, acids, salt, and other substances reduce perceived bitterness of several pharmaceuticals, and although pleasant flavorings may help children consume some medicines, they often are not effective in suppressing bitter tastes. Further development of psychophysical tools for children will help us better understand their sensory worlds. Multiple testing strategies will help us refine methods to assess acceptance and compliance by various pediatric populations. Research involving animal models, in which the gustatory system can be more invasively manipulated, can elucidate mechanisms, ultimately providing potential targets. These approaches, combined with new technologies and guided by findings from clinical studies, will potentially lead to effective ways to enhance drug acceptance and compliance in pediatric populations.

Comparison of physiological and behavioral responses to fresh and thawed breastmilk in premature infants--a preliminary study

BACKGROUND

Breastmilk is usually frozen for premature infants when they are unable to feed orally. However, thawed breastmilk may have altered odor and taste from its original form. Few studies have investigated whether premature infants respond differently to fresh and thawed breastmilk. The purpose of this study was to examine the physiological and behavior responses of premature infants alternately fed fresh and thawed breastmilk.

SUBJECTS AND METHODS

An experimental, crossover study using random assignment was conducted. A convenience sample of 18 premature infants less than 37 weeks gestational age at birth with the capability of oral feeding was studied. The premature infants were fed with fresh and thawed breastmilk during two consecutive meals in a random order. Infants' heart rate and oxygen saturation levels were measured baseline and during feeding, as well as observed feeding cues during the feeding period.

RESULTS

Premature infants showed significant differences in heart rate when fed thawed, as opposed to fresh, breastmilk. Premature infants demonstrated more stress cues when fed thawed compared with fresh breastmilk (p=0.007). For infants with postmenstrual ages greater than 36 weeks gestation, feeding with thawed breastmilk showed more stress cues and greater effect on heart rate activity compared with fresh breastmilk (p<0.05).

CONCLUSIONS

Older premature infants demonstrate more stress when fed with thawed breastmilk. Preterm infants should be directly breastfed or fed with nonfrozen breastmilk, when they show stress behaviors in being fed with thawed breastmilk.

Sweetness and food preference

Human desire for sweet taste spans all ages, races, and cultures. Throughout evolution, sweetness has had a role in human nutrition, helping to orient feeding behavior toward foods providing both energy and essential nutrients. Infants and young children in particular base many of their food choices on familiarity and sweet taste. The low cost and ready availability of energy-containing sweeteners in the food supply has led to concerns that the rising consumption of added sugars is the driving force behind the obesity epidemic. Low-calorie sweeteners are one option for maintaining sweet taste while reducing the energy content of children's diets. However, their use has led to further concerns that dissociating sweetness from energy may disrupt the balance between taste response, appetite, and consumption patterns, especially during development. Further studies, preferably based on longitudinal cohorts, are needed to clarify the developmental trajectory of taste responses to low-calorie sweeteners and their potential impact on the diet quality of children and youth.

Analgesic Effect of Oral Glucose in Neonates

The International Association for the Study of Pain, has defined pain as "an unpleasant sensory and emotional experience connected with actual or potential tissue damage or described in terms of such damage". It was thought that the newborn baby does not experience pain because of incompletely developed nervous system. However, it has been shown that neurological system known to be associated with pain transmission and modulation, is intact and functional. A study was conducted in our center to study the analgesic effect of administration of oral glucose in various concentrations, in neonates undergoing heel punctures, for collection of blood for investigations. This was compared with the analgesic effects of breast milk (which contains lactose). 125 full term normal neonates with no history of birth asphyxia or underlying neurological abnormality, requiring heel punctures for collection of blood for various investigations were selected for the study. They were matched for gestational age, birth weight and sex distribution and divided into 5 groups of 25 each. One group comprised control subjects and was administered sterile water. 3 groups were administered 1 ml of varying strengths of glucose solutions i.e. 10%, 25% and 50% respectively. The last group was given 1 ml of expressed breast milk (EBM). Prior to heel pricks, state of arousal, baseline heart rate (HR) and transcutaneous oxygen saturation (SpO2) were recorded by pulse oximeter in each neonate. Autolet, a mechanical device for capillary sampling, was used for heel pricks to give equal strength of painful stimulus in each procedure. Audio tape recorder was used to record the cry. The oral solution was administered slowly over 30 seconds by means of a syringe placed in the mouth. Heel puncture was done after 2 minutes, taking all aseptic precautions. HR and SpO2 were monitored using pulse oximeter. Pain response was assessed, by recording duration of crying, change in HR, change in SpO2 and facial action score after the procedure. Mean duration of cry and total cry over 5 minutes was significantly less in groups given 25% and 50% glucose solutions as compared to the control group and babies given EBM. Difference in mean increase in HR, fall in SpO2 were statistically significant between control group, EBM group and neonates given 25% and 50% glucose solutions respectively. Compared to control group, all other administered solutions (10%, 25%, 50% glucose and EBM) were found to reduce physiological and behavioral responses in neonates undergoing heel punctures. 25% and 50% glucose solutions were found to have maximal analgesic effect and both were found to be equally effective. EBM and 10% glucose solution have an equal analgesic effect but less than 25% or 50% glucose. This simple, cheap and safe method of oral analgesia can be easily used in neonates undergoing heel prick procedures during routine neonatal care.

Nonnutritive sweetener consumption in humans: effects on appetite and food intake and their putative mechanisms

Nonnutritive sweeteners (NNS) are ecologically novel chemosensory signaling compounds that influence ingestive processes and behavior. Only about 15% of the US population aged >2 y ingest NNS, but the incidence is increasing. These sweeteners have the potential to moderate sugar and energy intakes while maintaining diet palatability, but their use has increased in concert with BMI in the population. This association may be coincidental or causal, and either mode of directionality is plausible. A critical review of the literature suggests that the addition of NNS to non-energy-yielding products may heighten appetite, but this is not observed under the more common condition in which NNS is ingested in conjunction with other energy sources. Substitution of NNS for a nutritive sweetener generally elicits incomplete energy compensation, but evidence of long-term efficacy for weight management is not available. The addition of NNS to diets poses no benefit for weight loss or reduced weight gain without energy restriction. There are long-standing and recent concerns that inclusion of NNS in the diet promotes energy intake and contributes to obesity. Most of the purported mechanisms by which this occurs are not supported by the available evidence, although some warrant further consideration. Resolution of this important issue will require long-term randomized controlled trials.

Analgesia and sedation during mechanical ventilation in neonates

BACKGROUND

Endotracheal intubation and mechanical ventilation are major components of routine intensive care for very low birth weight newborns and sick full-term newborns. These procedures are associated with physiologic, biochemical, and clinical responses indicating pain and stress in the newborn. Most neonates receive some form of analgesia and sedation during mechanical ventilation, although there are marked variations in clinical practice. Clinical guidelines for pharmacologic analgesia and sedation in newborns based on robust scientific data are lacking, as are measures of clinical efficacy.

OBJECTIVE

This article represents a preliminary attempt to develop a scientific rationale for analgesia sedation in mechanically ventilated newborns based on a systematic analysis of published clinical trials.

METHODS

The current literature was reviewed with regard to the use of opioids (fentanyl, morphine, diamorphine), sedative-hypnotics (midazolam), nonsteroidal anti-inflammatory drugs (ibuprofen, indomethacin), and acetaminophen in ventilated neonates. Original meta-analyses were conducted that collated the data from randomized clinical comparisons of morphine or fentanyl with placebo, or morphine with fentanyl.

RESULTS

The results of randomized trials comparing fentanyl, morphine, or midazolam with placebo, and fentanyl with morphine were inconclusive because of small sample sizes. Meta-analyses of the randomized controlled trials indicated that morphine and fentanyl can reduce behavioral and physiologic measures of pain and stress in mechanically ventilated preterm neonates but may prolong the duration of ventilation or produce other adverse effects. Randomized trials of midazolam compared with placebo reported significant adverse effects (P < 0.05) and no apparent clinical benefit; the findings of a meta-analysis suggest that there are insufficient data to justify use of IV midazolam for sedation in ventilated neonates.

CONCLUSIONS

Despite ongoing research in this area, huge gaps in our knowledge remain. Well-designed and adequately powered clinical trials are needed to establish the safety, efficacy, and short- and long-term outcomes of analgesia and sedation in the mechanically ventilated newborn.

Newborns and drug studies: the NICHD/FDA newborn drug development initiative

BACKGROUND

Progress has been made in research on the effects of drug therapy on pediatric patients, but neonates are still an understudied population. Those most likely to receive drug therapy (eg, preterm infants) are least likely to be studied.

OBJECTIVES

The purposes of this article are to summarize an initiative developed jointly by the National Institute of Child Health and Human Development (NICHD) and the US Food and Drug Administration (FDA) and to introduce a series of articles developed as a result of this initiative.

METHODS

Information for this article was gathered from the proceedings of a workshop cosponsored by the NICHD and the FDA that took place March 29 and 30, 2004, in Rockville, Maryland.

RESULTS

: Dosing based on use in adults and older children has resulted in adverse events among newborn infants, and may have long-term effects. Moreover, formulations appropriate for use in neonates are often unavailable, and compensatory efforts such as mixing crushed tablets into formula may interfere with accurate dose delivery. Under the Best Pharmaceuticals for Children Act of 2002, government agencies work with experts in pediatrics and pediatric research to develop and prioritize a list of off-patent drugs for which pediatric studies are urgently needed. Four such listings were published in the Federal Register from January 2003 through January 2005. The NICHD and FDA have also initiated the Newborn Drug Development Initiative (NDDI), a multiphase program to determine gaps in knowledge concerning neonatal pharmacology and clinical trial design and to explore novel study designs for use in newborns, with the ultimate goal of increasing our knowledge about the safety and efficacy of drugs used to treat newborns.

CONCLUSIONS

Most drugs used to treat newborns still lack appropriate dosing, efficacy, and safety studies in this vulnerable population. The NICHD and FDA developed the NDDI as an ongoing process to identify and suggest strategies for addressing obstacles to conducting drug trials in the newborn.

Les perceptions gustatives chez l'enfant

As soon as the end of gestation, the gustatory system is stimulated by the taste-active compounds carried by the amniotic fluid and its maturation continues until mid-childhood. Facial expressions and relative ingestion methods show that the newborn can discriminate the various taste qualities (bitter, salty, sour, sweet and umami). The range of individual responses is wide. Neonatal reactions to sweet and umami are generally considered to express pleasure. The bitter and sour stimulations lead to hedonically negative reactions. The response to salt taste is less characteristic. Overall, the attraction towards sweet and the rejection of bitter and sour tastes become more pronounced during childhood but tend to decrease in adult life. The early attraction to sweetness is reinforced by exposure to sweet stimulations. With age, the response to salt evolves towards attraction which intensity is dependent on the context and on postnatal exposures to salt. The link between gustatory sensitivity to sweet, salty and sour stimuli and food preferences is far from being clear; the sensitivity to bitter taste better explains the rejection of bitter foods, such as vegetables for instance. The development of gustatory perceptions partly depends upon experience. A better knowledge of the role of experience could help to improve the orientation and the efficacy of nutritionally-oriented food education strategies.

Artificial sweeteners--do they bear a carcinogenic risk?

Artificial sweeteners are added to a wide variety of food, drinks, drugs and hygiene products. Since their introduction, the mass media have reported about potential cancer risks, which has contributed to undermine the public's sense of security. It can be assumed that every citizen of Western countries uses artificial sweeteners, knowingly or not. A cancer-inducing activity of one of these substances would mean a health risk to an entire population. We performed several PubMed searches of the National Library of Medicine for articles in English about artificial sweeteners. These articles included 'first generation' sweeteners such as saccharin, cyclamate and aspartame, as well as 'new generation' sweeteners such as acesulfame-K, sucralose, alitame and neotame. Epidemiological studies in humans did not find the bladder cancer-inducing effects of saccharin and cyclamate that had been reported from animal studies in rats. Despite some rather unscientific assumptions, there is no evidence that aspartame is carcinogenic. Case-control studies showed an elevated relative risk of 1.3 for heavy artificial sweetener use (no specific substances specified) of >1.7 g/day. For new generation sweeteners, it is too early to establish any epidemiological evidence about possible carcinogenic risks. As many artificial sweeteners are combined in today's products, the carcinogenic risk of a single substance is difficult to assess. However, according to the current literature, the possible risk of artificial sweeteners to induce cancer seems to be negligible.

Early flavor experiences: research update

Anyone who has observed infants for any period of time can testify to the intense activity occurring in and around their mouths--the primary site for learning in the first few months of life. Before they are even able to crawl, infants have learned much about their new sensory world. Though recent research we have begun to explore the impact of these early experiences on infants' acceptance of solid foods and how they explore objects in their environment. We have also begun to focus on the sensory experiences of the formula-fed infant, in particular, how their responses to particular formulas, which are extremely unpalatable to older children and adults, change during infancy. This is a relatively new and exciting area of study, with much research yet to be done. It is clear, however, that infants are not passive receptacles for flavored foods. Parents who offer a variety of foods will provide both a nutritious, well-balanced diet, as well as an opportunity for their children's own personal preferences to develop.

Effects of sweet taste stimulation on growth and sucking in preterm infants

OBJECTIVE

To evaluate the effect of sweet taste stimulation in augmenting the reported growth-enhancing effects of nonnutritive sucking in preterm infants who are gavage-fed.

DESIGN

Random assignment of preterm infants to receive stimulation by one of three methods during each feeding until totally orally fed.

SETTING

Hospital intensive-care and infant transitional units.

PATIENTS

Eligibility criteria included body weight greater than or equal to 1,250 g, gestational age younger than 34 weeks, growth parameters appropriate for gestational age, tolerating at least 100 kcals/kg/day by gavage feeding with evidence of weight gain, and no clinical evidence of health complications. Data are presented for 42 infants who completed 14 days of treatment.

INTERVENTIONS

Exposure to a sweet pacifier, a latex pacifier, or maternal heartbeat sounds during gavage feedings.

MAIN OUTCOME MEASURES

Growth, time to total oral feeding, and sucking responses.

RESULTS

No significant differences in sucking measures were noted among treatment groups. Differences in progression time to total oral feedings and weight gain favored the sweet-pacifier group but were not statistically significant.

CONCLUSIONS

Oral stimulation of gavage-fed, preterm infants during a 2-week hospitalization was not sufficient to elicit a significant improvement in growth efficiency, progression to total oral feedings, or sucking maturation. Additional studies may show a beneficial effect of chemosensory stimulation in preterm infants.

Reduction of pain response in premature infants using intraoral sucrose

The potential of sucrose to reduce the pain response in a group of healthy premature infants was investigated. Fifteen infants of 32-34 weeks postmenstrual age were tested in a blind crossover manner on two separate occasions no more than two days apart. Either 1 ml of 25% sucrose solution or sterile water was syringed into the baby's mouth 2 minutes before routine heel lancing. Response to the painful stimuli was measured by duration of cry and by facial expression (pain score). There was a significant reduction in the duration of first cry, the percentage of time spent crying in the 5 minutes after heel prick, and the pain score in the sucrose treated group. It is concluded that sucrose has analgesic effects in healthy premature infants.

Dietary guidelines for infants: a timely reminder

The 1995 edition of Dietary Guidelines for Americans has recently been released. In anticipation of the heightened attention that these revised will undoubtedly receive, there is renewed discussion about the need for Dietary Guidelines for Infants. These guidelines would reinforce to parents and nutrition professionals that many diet strategies designed to promote adult health and nutrition are inappropriate for infants and children under the age of two. These guidelines, developed in 1994 by the Gerber Products Company, seek to distinguish the unique dietary needs of this vulnerable population.

Bitter taste in aging: compound-specific decline in sensitivity

Threshold sensitivity to and the perceived intensity of two bitter compounds, quinine sulfate and urea, were assessed in 52 young adults and 60 elderly adults. Consistent with previous literature, age-related declines in sensitivity to the bitterness of quinine were observed at both threshold and suprathreshold levels. In contrast, the same young and elderly subjects showed comparable sensitivity to the bitterness of urea. These results provide further support for the existence of multiple bitter taste transduction sequences in humans, and indicate that they may be differentially affected by aging.