Caffeine content of beverages as consumed.
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Quantitative analysis of beverages prepared at home by staff of the Addiction Research Foundation revealed a lower and much more variable caffeine content of both tea and coffee than had been reported in earlier studies, most of which were based on analysis of laboratory-prepared beverages. Median caffeine concentration of 37 home-prepared samples of tea was 27 mg per cup (range, 8 to 91 mg); for 46 coffee samples the median concentration was 74 mg per cup (range, 29 to 176 mg). If tea and coffee as drunk contain less caffeine than generally supposed, the potency of caffeine may be greater than commonly realized, as may the relative caffeine content of certain commercial preparations, including chocolate and colas. The substantial variation in caffeine content emphasizes the need to establish actual caffeine intake in clinical, epidemiologic and experimental investigations of caffeine effects. (+info)
Neurobiological and psychophysical mechanisms underlying the oral sensation produced by carbonated water.
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Carbonated drinks elicit a sensation that is highly sought after, yet the underlying neural mechanisms are ill-defined. We hypothesize that CO(2) is converted via carbonic anhydrase into carbonic acid, which excites lingual nociceptors that project to the trigeminal nuclei. We investigated this hypothesis using three methodological approaches. Electrophysiological methods were used to record responses of single units located in superficial laminae of the dorsomedial aspect of trigeminal subnucleus caudalis (Vc) evoked by lingual application of carbonated water in anesthetized rats. After pretreatment of the tongue with the carbonic anhydrase inhibitor dorzolamide, neuronal responses to carbonated water were significantly attenuated, followed by recovery. Using c-Fos immunohistochemistry, we investigated the distribution of brainstem neurons activated by intraoral carbonated water. Fos-like immunoreactivity (FLI) was significantly higher in the superficial laminae of dorsomedial and ventrolateral Vc in animals treated with carbonated water versus controls. Dorzolamide pretreatment significantly reduced FLI in dorsomedial Vc. We also examined the sensation elicited by carbonated water in human psychophysical studies. When one side of the tongue was pretreated with dorzolamide, followed by bilateral application of carbonated water, a significant majority of subjects chose the untreated side as having a stronger sensation and assigned significantly higher intensity ratings to that side. Dorzolamide did not reduce irritation elicited by pentanoic acid. The present data support the hypothesis that carbonated water excites lingual nociceptors via a carbonic anhydrase-dependent process, in turn exciting neurons in Vc that are presumably involved in signaling oral irritant sensations. (+info)
An experimental investigation of the influence of health information on children's taste preferences.
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Promotion of healthy diets often involves provision of information about which food types are most favourable for health. This is based on the assumption that the rational consumer will, other things being equal, choose the food that they know is healthier. However, health information may not always have a positive effect, since there is evidence that some people, particularly children, believe that healthiness and tastiness are mutually exclusive characteristics. To the extent that taste governs preferences and consumption, the characterization of a food as healthy could reduce its anticipated pleasantness. The present study tested the idea that a 'healthy' label would reduce liking for a novel drink. The results showed that the children rated a 'healthy labelled' drink as less pleasant and said they would be less likely to ask their parents to buy it than the same drink presented with control information. These results suggest that care may need to be exercised in promoting foods to children through an emphasis on health, unless the implications of healthiness can be rendered more positive. (+info)
Small taxes on soft drinks and snack foods to promote health.
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Health officials often wish to sponsor nutrition and other health promotion programs but are hampered by lack of funding. One source of funding is suggested by the fact that 18 states and 1 major city levy special taxes on soft drinks, candy, chewing gum, or snack foods. The tax rates may be too small to affect sales, but in some jurisdictions, the revenues generated are substantial. Nationally, about $1 billion is raised annually from these taxes. The authors propose that state and local governments levy taxes on foods of low nutritional value and use the revenues to fund health promotion programs. (+info)
Maternal milk consumption predicts the tradeoff between milk and soft drinks in young girls' diets.
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Milk intake constitutes an important source of dietary calcium for young girls but declines throughout childhood. Recent work shows that the intake of soft drinks may contribute to this decline. Influences on the apparent tradeoff between soft drinks and milk in young girls' diets are not well described. The objective of this research was to test a model depicting maternal beverage choices as predictors of their daughters' milk and soft drink intake. A structural equation model describing maternal influences on daughters' milk, soft drink and calcium intakes was tested using data from 180 non-Hispanic, white families with 5-y-old daughters. Mothers' calcium, milk and soft drink intakes were evaluated as predictors of their daughters' intakes. Mothers' and daughters' soft drink intakes were also examined as predictors of their own milk and calcium intakes. The model provided a good fit to the data, revealing mother-daughter similarities in beverage intake. Mothers who drank milk more frequently had daughters who drank milk more frequently and drank fewer soft drinks. For both mothers and daughters, soft drink consumption was negatively related to both milk and calcium intake. This research provides evidence that mothers' beverage choices influence the tradeoff between milk and soft drinks in their daughters' diets. In particular, mothers' milk and soft drink intakes may affect their daughters' calcium adequacy in early childhood by influencing the frequency with which their daughters consume those beverages. (+info)
Dental erosion in a group of British 14-year-old school children. Part II: Influence of dietary intake.
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OBJECTIVES: The aims of the present study were first to investigate the dietary intake pattern of UK teenagers and secondly to determine the relationship, if any, between dental erosion and dietary intake in these children. METHODS: The study group consisted of a cluster random sample of 14-year-old school children in Birmingham, UK: 418 children were examined from 12 different schools; 209 were male and 209 female. Data on the rate and frequency of consumption of drinks, foods, and fruits were obtained from a self-reported questionnaire supplemented by a structured interview. The data were analysed using SPSS with Chi-square, and Spearman correlation analysis. RESULTS: Over 80% of the teenagers regularly consumed soft drinks but approximately half of these children had a relatively low weekly consumption. However, 13% and 10% respectively had more than 22 intakes per week of cola and other carbonated drinks. Almost a quarter of these 14-year-olds had alcoholic drinks, with significantly more males than females involved (Chi-square P < 0.05) . Girls had a greater intake of fruits. Statistically significant correlations were found between the prevalence of erosion and the consumption of soft drinks, carbonated beverages, alcohol drinks, fresh fruits, Vitamin-C tablets and foodstuffs (Spearman correlation analysis P < 0.05). CONCLUSION: It was concluded that consumption particularly of soft drinks was high and common in teenage school children in Birmingham, UK. In addition there was a relationship between dental erosion and acidic dietary intake. Further investigation of the erosive potential of these drinks and foods is required. (+info)
The oral sensation of carbonated water: cross-desensitization by capsaicin and potentiation by amiloride.
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The oral sensation elicited by carbonated water is reduced by capsaicin and by blockers of carbonic anhydrase. We have investigated the temporal profile of this sensation and its cross-desensitization by capsaicin. We additionally tested if the sensation is influenced by amiloride. Following pretreatment of half of the dorsal tongue with 33 p.p.m. capsaicin, carbonated water was flowed over the tongue bilaterally for 5, 15 or 60 s. Subjects then performed a two-alternative forced choice test by indicating which side of the tongue had a stronger sensation and separately rated the sensory intensity on each side. Capsaicin significantly reduced the intensity of sensation elicited by carbonated water, consistent with cross-desensitization. This effect was weaker at 60 s because of a significant decline (desensitization) in ratings of the intensity of carbonated water on both sides of the tongue. Pretreatment with amiloride resulted in a small but significant increase in the intensity of the sensation elicited by the 15 s carbonated water stimulus, suggesting an amiloride-sensitive transduction mechanism. (+info)
Carbonated beverages and urinary calcium excretion.
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BACKGROUND: Intake of carbonated beverages has been associated with increased fracture risk in observational studies. The usual explanation given is that one or more of the beverage constituents increase urinary calcium. OBJECTIVE: We assessed the short-term effects on urinary calcium excretion of carbonated beverages of various compositions. DESIGN: An incomplete random block design was used to study 20-40-y-old women who customarily consumed > or =680 mL carbonated beverages daily. Four carbonated beverages were tested: 2 with caffeine and 2 without. Two contained phosphoric acid as the acidulant and 2 contained citric acid. The study included one neutral control (water) and one positive control (skim or chocolate milk). Serving size was 567 mL for the carbonated beverages and water and 340 mL for the milks. Beverages were consumed with a light breakfast after an overnight fast; no other foods were ingested until urine collection was complete. pH, titratable and total acidity, sodium, creatinine, and calcium were measured in 2-h (morning) fasting and 5-h postbeverage urine specimens. RESULTS: Relative to water, urinary calcium rose significantly only with the milks and the 2 caffeine-containing beverages. The excess calciuria was approximately 0.25 mmol, about the same as previously reported for caffeine alone. Phosphoric acid without caffeine produced no excess calciuria; nor did it augment the calciuria of caffeine. CONCLUSIONS: The excess calciuria associated with consumption of carbonated beverages is confined to caffeinated beverages. Acidulant type has no acute effect. Because the caffeine effect is known to be compensated for by reduced calciuria later in the day, we conclude that the net effect of carbonated beverage constituents on calcium economy is negligible. The skeletal effects of carbonated beverage consumption are likely due primarily to milk displacement. (+info)