Sucrose-induced analgesia is related to sweet preferences in children but not adults

Taste damage (otitis media, tonsillectomy and head and neck cancer), oral sensations and BMI

Otitis media and tonsillectomy are associated with enhanced palatability of energy dense foods and with weight gain. Otitis media can damage the chorda tympani nerve (CN VII); tonsillectomy and head and neck radiation treatment can damage the glossopharyngeal nerve (CN IX). Both of these nerves function prominently in taste sensation. The present study utilizes these sources of damage to study central interactions among the nerves that mediate oral sensations. Mild damage restricted to one of these nerves can actually intensify sensations evoked from undamaged nerves (i.e., whole-mouth taste, oral tactile sensations evoked by fats and irritants). These intensifications may result from disruption of central inhibitory taste circuits, as taste damage appears to disinhibit other oral sensory nerves. In addition, mild damage restricted to one taste nerve can intensify odors perceived from foods in the mouth during chewing and swallowing (i.e., retronasal olfaction); this may be a secondary consequence of the intensification of whole-mouth taste. Damage to both nerves leads to widespread oral sensory loss. At present, the link between sensory alterations and weight gain has not been established for adults (e.g., does increased fat preference occur in individuals with oral sensory intensifications, those with losses, or both?). Finally, pain in non-oral locations is also related to taste loss. When participants rated "the most intense pain of any kind they had ever experienced," those with the greatest taste loss gave the highest ratings. These effects suggest that taste loss significantly influences long-term health outcomes.

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.

The proof is in the pudding: children prefer lower fat but higher sugar than do mothers

OBJECTIVE

Although there are established age-related differences in sweet preferences, it remains unknown whether children differ from mothers in their preference for and perception of fat (creaminess). We examined whether individual differences in sucrose and fat preferences and perception are related to age, genotype and lifestyle.

SUBJECTS

Children 5-10 years-old (n=84) and their mothers (n=67) chose the concentration of sucrose and fat most preferred in pudding and sucrose most preferred in water using identical, two-alternative, forced-choice procedures, and ranked pudding samples for intensity of sweetness and creaminess. Subjects were also weighed and measured for height, as well as genotyped for a sweet-receptor gene (TAS1R3).

RESULTS

Children preferred higher concentrations of sucrose in water (P=0.03) and in pudding (P=0.05) and lower concentrations of fat in pudding (P<0.01) than did mothers. Children and mothers were equally able to rank the intensity of different concentrations of fat (P=0.12) but not sucrose in pudding (P=0.01). Obese and lean children and mothers did not differ in preferences, but obese mothers were less able to correctly rank the concentration of fat in pudding than were lean mothers (P=0.03). Mothers who smoked preferred a higher concentration of sucrose than did those who never smoked (P<0.01). Individual differences in sweet preference were associated with genetic variation within the TAS1R3 gene in mothers but not children (P=0.04).

CONCLUSION

Irrespective of genotype, children prefer higher concentrations of sugar but lower concentrations of fat in puddings than do their mothers. Thus, reduced-fat foods may be better accepted by children than adults.

Sweet taste and menthol increase cough reflex thresholds

Cough is a vital protective reflex that is triggered by both mechanical and chemical stimuli. The current experiments explored how chemosensory stimuli modulate this important reflex. Cough thresholds were measured using a single-inhalation capsaicin challenge. Experiment 1 examined the impact of sweet taste: Cough thresholds were measured after rinsing the mouth with a sucrose solution (sweet) or with water (control). Experiment 2 examined the impact of menthol: Cough thresholds were measured after inhaling headspace above a menthol solution (menthol vapor) or headspace above the mineral oil solvent (control). Experiment 3 examined the impact of rinsing the mouth with a (bitter) sucrose octaacetate solution. Rinsing with sucrose and inhaling menthol vapor significantly increased measured cough thresholds. Rinsing with sucrose octaacete caused a non-significant decrease in cough thresholds, an important demonstration of specificity. Decreases in cough reflex sensitivity from sucrose or menthol could help explain why cough syrups without pharmacologically active ingredients are often almost as effective as formulations with an added drug. Further, the results support the idea that adding menthol to cigarettes might make tobacco smoke more tolerable for beginning smokers, at least in part, by reducing the sensitivity of an important airway defense mechanism.

Interactive effects of dietary restraint and adiposity on stress-induced eating and the food choice of children

The Individual Differences Model posits that individual differences in physiological and psychological factors explain eating behaviors in response to stress. The purpose was to determine the effects of individual differences in adiposity, dietary restraint and stress reactivity on children's energy intake and food choices. A total of 40 boys and girls, age 8-12 years, with wide ranges of dietary restraint, adiposity, and stress reactivity were measured for total energy intake and choice of energy dense 'comfort' and lower density 'healthy' foods following reading and speech stressor manipulations. When exploring the interaction of dietary restraint and stress reactivity, lower restraint/lower reactivity and lower restraint/higher reactivity were associated with reductions in energy intake (37-62 kcal) and comfort food (33-89 kcal). Higher restraint/lower reactivity was associated with consuming 86 fewer total kcal and 45 fewer kcal of comfort food. Only higher restraint/higher reactivity predicted increased energy intake (104 kcal) and comfort food (131 kcal). The interaction of dietary restraint and percentage body fat revealed that lower restraint/lower adiposity was associated with consuming 123 fewer kcal after being stressed with the entire reduction due to a decrease in comfort food. Lower restraint/higher adiposity was associated with consuming 116 kcal more after being stressed with 70% (81 kcal) of the increase in the form of comfort foods. Higher restraint/lower adiposity and higher restraint/higher adiposity were associated with smaller changes in total energy intake of 22 kcal and 1 kcal; respectively. Both restraint and adiposity moderated the effect of stress on energy intake and food choice. Children with greater adiposity may be at risk for stress-induced eating to contribute to their obesity.

Sweet tasting solutions for reduction of needle-related procedural pain in children aged one to 16 years

BACKGROUND

Large numbers of studies have shown that oral sucrose or glucose, with or without non-nutritive sucking given prior to painful procedures result in a significant reduction in behavioral pain responses during or following painful procedures compared with placebo, no treatment or non-nutritive sucking alone, in newborns and infants up to 12 months of age. It is not known if these pain-reducing effects exist for older infants and children one year to 16 years of age.

OBJECTIVES

To determine the efficacy of sweet tasting solutions or substances for reducing needle-related procedural pain in children beyond one year of age.

SEARCH STRATEGY

We searched the following databases: the Cochrane Register of Controlled Trials (CCTR), MEDLINE, EMBASE, PsycINFO, ACP Journal Club, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Cochrane Methodology Register, Health Technology Assessment, and the NHS Economic Evaluation Database, and on the EBSCOhost interface: CINAHL. We applied no language or document type restrictions. We used the standard methods of The Cochrane Collaboration. The last date of the search was June 30, 2011.

SELECTION CRITERIA

Randomized controlled trials (RCTs) in which children from one year up to 16 years of age, received a sweet tasting solution or substance for needle-related procedural pain. Control conditions included water, non-sweet tasting substances, pacifier, distraction, no treatment, positioning/containment or breastfeeding.

DATA COLLECTION AND ANALYSIS

Outcome measures included composite pain scores, physiological or behavioral pain indicators, self-report of pain or parental- or healthcare professional-report of child's pain. We reported mean differences (MD) with 95% confidence intervals (CI) using fixed-effect or random-effects models as appropriate for continuous outcome measures. We planned to report risk ratio (RR) and risk difference (RD) for dichotomous outcomes. We used the Chi(2) test and I(2) statistic to assess between-study heterogeneity.

MAIN RESULTS

We included four studies (330 participants). Two studies focused on toddlers and pre-school children receiving sucrose for immunization pain compared with water or no treatment and two studies included school-aged children receiving sweet or unsweetened chewing gum before, or, before and during immunization and blood collection. Results for the toddlers/pre-school children were conflicting. Participants in the sucrose group in one study had significantly lower cry duration and behavioral pain scores, compared with the no intervention group, while crying time did not differ between the sucrose and the no intervention group in the other study. For school-aged children, chewing sweet gum either before, or during the procedure, did not significantly reduce pain scores.

AUTHORS' CONCLUSIONS

Based on these four studies, two of which were subgroups of small numbers of eligible toddlers from larger studies, there is insufficient evidence of the analgesic effects of sweet tasting solutions or substances during acute painful procedures in children over one year of age. Further well-conducted RCTs are warranted in this population.

Gut feelings: the emerging biology of gut-brain communication

The concept that the gut and the brain are closely connected, and that this interaction plays an important part not only in gastrointestinal function but also in certain feeling states and in intuitive decision making, is deeply rooted in our language. Recent neurobiological insights into this gut-brain crosstalk have revealed a complex, bidirectional communication system that not only ensures the proper maintenance of gastrointestinal homeostasis and digestion but is likely to have multiple effects on affect, motivation and higher cognitive functions, including intuitive decision making. Moreover, disturbances of this system have been implicated in a wide range of disorders, including functional and inflammatory gastrointestinal disorders, obesity and eating disorders.

Innate and learned preferences for sweet taste during childhood

PURPOSE OF REVIEW

In nature, carbohydrates are a source of energy often equated with sweetness, the detection of which is associated with powerful hedonic appeal. Intakes of processed carbohydrates in the form of added sugars and sugar-sweetened beverages have risen consistently among all age groups over the last two decades. In this review, we describe the biological underpinnings that drive the consumption of sweet-tasting foods among pediatric populations.

RECENT FINDINGS

Scientific literature suggests that children's liking for all that is sweet is not solely a product of modern-day technology and advertising but reflects their basic biology. In fact, heightened preference for sweet-tasting foods and beverages during childhood is universal and evident among infants and children around the world. The liking for sweet tastes during development may have ensured the acceptance of sweet-tasting foods, such as mother's milk and fruits. Moreover, recent research suggests that liking for sweets may be further promoted by the pain-reducing properties of sugars.

SUMMARY

An examination of the basic biology of sweet taste during childhood provides insight, as well as new perspectives, for how to modify children's preferences for and intakes of sweet foods to improve their diet quality.

Sweet taste-induced analgesia: an fMRI study

We investigated the brain activation associated with sweet taste-induced analgesia by 3-T functional magnetic resonance imaging, the mechanism of which is considered to involve the central nervous system. After 12 healthy individuals ingested tasteless gelatin (nonsweet condition) or sweet glucose (sweet condition) in a magnetic resonance imaging scanning gantry, the cold pressor test was applied to their medial forearm. Under both conditions, the cold pressor test robustly activated the pain-related neural network, notably the anterior cingulate cortex, insula, posterior parietal cortex, and thalamus, although such activations under the sweet condition weakened with pain threshold increase, compared with those under the nonsweet condition. Together with emotional changes in pain appraisal, our findings provide objective representation of sweet taste-induced analgesia in the human brain.

Gender differences in pain modulation by a sweet stimulus in adults: A randomized study

This study aimed to examine whether or not there are gender differences in sweet stimulus-induced analgesia for cold pain in adults. In a randomized cross-over design, twenty men and 20 women held either a 24% sucrose solution or distilled water in their mouth before and while they immersed their hand in cold water and their pain response was examined. Unlike the women, when the men held the sucrose solution in their mouth, the latency of the onset of pain significantly increased, compared with the distilled water. Meanwhile, the level of pain tolerance was not significantly different for both sexes. The findings reveal that the analgesic effect of a sweet stimulus on the pain threshold is influenced by gender differences in human adults, indicating that sweet stimulus-induced analgesia has a brief analgesic effect, particularly for men. Although more research is warranted, the sweet stimulus could be put to practical application as an adjunct to acute pain management for men.

Pain in neonates is different

Pain processing and management in neonates, especially preterm neonates, differs from older populations. In this review, a brief background on pain processing in neonatal life, pain exposure in Neonatal Intensive Care Units (NICU), the consequences of untreated pain, and the difficulties in treating procedural pain pharmacologically will be presented. A more detailed review of non-pharmacological interventions for procedural pain in neonates will include sensory stimulation approaches, oral sweet solutions, and maternal interventions. Some possible mechanisms for the effectiveness of non-pharmacological interventions are offered. Finally, avenues of research into similar interventions as adjuvant therapies or drug-sparing effects in older populations are suggested.

A spoonful of sugar helps the medicine go down: a novel technique to improve oral gavage in mice

Oral gavage is a common route of precise oral dosing for studies in rodents. Complications including tracheal administration, esophageal trauma, and aspiration are common and usually related to animal resistance to the procedure, and the stress induced by oral gavage can be a confounding variable in many studies. The taste of sucrose conveys a pacifying and analgesic effect in newborns, whereas sour solutions can induce the swallow reflex in humans that are dysphagic. We hypothesized that precoating a gavage needle with sucrose or citrate (or both) would pacify mice and induce them to swallow, reducing the stress and complications associated with the technique. To validate this hypothesis, we quantitated time to passage, stress-related behavioral reactions to the procedure, and plasma corticosterone levels in mice after precoating gavage needles with water, sucrose, citrate, sucrose and citrate, or sodium chloride prior to oral gavage. Precoating needles with sucrose reduced the time to passage, decreased observable stress-related reactions to the procedure, and maintained plasma corticosterone levels similar to those in ungavaged control mice. Coating needles with water, sucrose and citrate, or citrate had no beneficial effects on these parameters. Our findings describe a novel, validated technique that measurably decreases signs of stress and thereby improves animal welfare during oral gavage. Furthermore, the use of sucrose may be a valuable tool to refine other minor or nonsurgical procedures in the field of laboratory animal research.

Sweet preferences and analgesia during childhood: effects of family history of alcoholism and depression

AIM

To determine whether depression and family history of alcoholism are associated with heightened sweet preferences in children, before they have experienced alcohol or tobacco and at a time during the life-span when sweets are particularly salient. Design Between- and within-subject experimental study.

PARTICIPANTS

Children, 5-12 years old (n = 300), formed four groups based on family history of alcohol dependence up to second-degree relatives [positive (FHP) versus negative (FHN)] and depressive symptoms as determined by the Pictorial Depression Scale [depressed (PDEP) versus non-depressed (NDEP)].

MEASUREMENTS

Children were tested individually to measure sucrose preferences, sweet food liking and, for a subset of the children, the analgesic properties of sucrose versus water during the cold pressor test.

FINDINGS

The co-occurrence of having a family history of alcoholism and self-reports of depressive symptomatology was associated significantly with a preference for a more concentrated sucrose solution, while depressive symptomatology alone was associated with greater liking for sweet-tasting foods and candies and increased pain sensitivity. Depression antagonized the analgesic properties of sucrose.

CONCLUSIONS

While children as a group innately like sweets and feel better after eating them, the present study reveals significant contributions of family history of alcoholism and depression to this effect. Whether the heightened sweet preference and the use of sweets to alleviate depression are markers for developing alcohol-related problems or responses that are protective are important areas for future research.

Effect of Red Bull energy drink on cardiovascular and renal function

Energy drink consumption has been anecdotally linked to the development of adverse cardiovascular effects in consumers, although clinical trials to support this link are lacking. The effects of Red Bull energy drink on cardiovascular and neurologic functions were examined in college-aged students enrolled at Winona State University. In a double-blind experiment where normal calorie and low calorie Red Bull were compared to normal and low calorie placebos, no changes in overall cardiovascular function nor blood glucose (mg/dL) were recorded in any participant (n = 68) throughout a 2-h test period. However, in the second experiment, nine male and twelve female participants subjected to a cold pressor test (CPT) before and after Red Bull consumption showed a significant increase in blood sugar levels pre- and post Red Bull consumption. There was a significant increase in diastolic blood pressure of the male volunteers immediately after submersion of the hand in the 5 degrees C water for the CPT. Under the influence of Red Bull, the increase in diastolic pressure for the male participants during the CPT was negated. There were no significant changes in the blood pressure of the female participants for the CPT with or without Red Bull. Finally, the CPT was used to evaluate pain threshold and pain tolerance before and after Red Bull consumption. Red Bull consumption was associated with a significant increase in pain tolerance in all participants. These findings suggest that Red Bull consumption ameliorates changes in blood pressure during stressful experiences and increases the participants' pain tolerance.

Similarities in food cravings and mood states between obese women and women who smoke tobacco

The present study assessed food cravings in a cohort of 229 women who differed in smoking history (i.e., never smoker, former smoker, and current smoker) and body weight (i.e., normal weight, overweight, and obese). Each subject completed the Food Craving Inventory (FCI), which measures cravings for sweets, high fats, carbohydrates/starches, and fast-food fats, and the Profile of Mood States (POMS), which measures psychological distress. Smoking and obesity were independently associated with specific food cravings and mood states. Current smokers craved high fats more frequently than former and never smokers. They also craved starches more frequently and felt more depressed and angry than never smokers, but not former smokers. Whereas cravings for starchy foods and some mood states may be characteristic of women who are likely to smoke, more frequent cravings for fat among smokers is related to smoking per se. Similarly, obese women craved high fats more frequently than nonobese women and depression symptoms were intensified with increasing body weights. We hypothesize that the overlapping neuroendocrine alterations associated with obesity and smoking and the remarkable similarities in food cravings and mood states between women who smoke and women who are obese suggest that common biological mechanisms modulate cravings for fat in these women.

Optimizing oral medications for children

BACKGROUND

Active pharmaceutical ingredients that taste bitter and/or irritate the mouth and throat are aversive to children as well as many adults. Effective methods of avoiding unpleasant tastes for adults (eg, encapsulating the medicine in pill, capsule, or tablet form) are problematic because many children cannot or will not swallow these. The unpalatable flavor of the medicine can thwart the benefits of even the most powerful of drugs. Failure to consume medication may do the child harm and can even be life-threatening.

OBJECTIVES

This article provides an overview of the current knowledge of the sensory capabilities and preferences of children as it relates to flavor, defined here as the combined input of taste, smell, and chemical irritation. The methods used to evaluate flavor perception in children are reviewed. Recent scientific advances are summarized that shed light on why the bitter taste of oral pharmaceuticals is an ongoing formulation problem and how discoveries of novel flavor molecules and modulators of bitter tastes hold considerable promise for the future. Alternative methods for evaluation of the palatability of medicines are described.

METHODS

The Eunice Kennedy Shriver National Institute of Child Health and Human Development sponsored a Pediatric Formulation Initiative workshop on December 6 and 7, 2005, in Bethesda, Maryland. Information for this article was gathered from literature reviews that were then discussed during this workshop as well as during several conference calls with the Taste and Flavor Working Group members. Terms for the MEDLINE search (1970-2007) included infant, children, taste, olfaction/smell, flavor, chemical senses, palatability, sensory testing, pharmaceutical, and medicines.

RESULTS

Children have well-developed sensory systems for detecting tastes, smells, and chemical irritants, and their rejection of unpalatable medications is a reflection of their basic biology. Sugars, salt, and other substances reportedly reduce the bitterness of several pharmaceuticals. Adding pleasant flavor volatiles such as bubble gum may help induce children to consume a medicine, but such volatile compounds are not effective in suppressing the strong bitter tastes associated with some medications. Also, because individual experiences and culture mainly determine which odors are attractive, a universally appealing volatile flavoring agent may be difficult to identify. Sensory panelists who are sensitive to the pediatric palate, which is different from adults, and new techniques involving animal models, isolated parts of the receptor cells, and even electronic devices that detect taste and flavor are among the tools that may be used to evaluate the palatability of medications and predict compliance among pediatric populations.

CONCLUSIONS

Although there are no easy solutions to this dilemma, children's acceptance of many medicines can be improved by applying the knowledge gleaned from basic research in the chemical senses. Further development and validation of sensory methods will provide a better understanding of the sensory world of the child. This understanding, combined with new technologies and results of animal model studies, will enhance drug acceptance and compliance in pediatric populations. A better understanding of the scientific basis for distaste and how to ameliorate it is a public health priority.

A marker of growth differs between adolescents with high vs. low sugar preference

Sweet preference is higher in childhood than adulthood but the mechanism for this developmental shift is not known. The objective of this study was to assess perceptual, physiological and eating habit differences between children preferring solutions high in sugar (high preference) and children preferring solutions low in sugar (low preference). We tested 143 children (11- to 15-years old) using sip and spit methodology to assess their hedonic profile, detection threshold, and perceived intensity of sucrose. Their plasma concentration of several hormones, a biomarker of bone-growth, body size, puberty stage, and dietary habits were measured. Eighty-eight children were classified as high preference and 53 were classified as low preference based on their hedonic ratings to a series of sucrose solutions. A marker of bone growth measured in urine and plasma leptin adjusted for body weight were significantly lower in the low preference group. Children with high and low preference patterns did not differ in sensory aspects of sucrose perception, nor did they differ in age, body mass index percentile, or dietary restraint. The change in sugar preference from high to low during adolescence appears to be associated with the cessation of growth.