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Kaffet började ursprungligen konsumeras för koffeinets effekter, vidare utvecklades kaffet och blev en social dryck. Kaffe spreds runt hela världen och koffeinet användes som tillsatts i energidryck och andra livsmedel. Syftet är att undersöka utvecklingen av koffeinets konsumtionsmönster och sociala roll i kaffe och energidryck. Arbetet är en litteraturstudie baserad på fyra vetenskapliga artiklar som samlats in genom två olika databaser. Urvalet av artiklar skedde med hjälp av förbestämda kriterier. Resultatet visar att koffein i dryck ger njutningsfyllda effekter men även bieffekter finns. Koffeinet har utvecklats som tillsatts i bland annat energidryck samt läsk och konsumtion av energidryck kopplas till problembeteenden. Detta livsmedel konsumeras ibland med alkohol och det finns konsekvenser med denna konsumtion. Kaffet har utvecklats till en social dryck och det går koppla denna dryck samt te till olika livsstilar. I diskussionen påvisas det att kaffe och te har en stors ocial roll i samhället. Energidryck och läskedryck visar sig inte ha någon förankring som en social dryck. Vidare talas det om konsumtionen av kaffe, energidryck, te och läskedryck. Konsumtionen av koffeinhaltiga drycker ökar men huruvida kaffet kommer ha en central roll  bland de sociala dryckerna i framtiden är osäkert. / B-uppsatser

by Chiu Pui Yu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 86-118). / Abstracts in English and Chinese. / Title Page --- p.i / Abstract --- p.ii-iv / Acknowledgement --- p.v / Table of Contents --- p.vi-viii / List of Tables --- p.ix / List of Figures --- p.x-xii / List of Abbreviations --- p.xiii / Chapter Section I: --- Introduction / Chapter Chapter 1: --- Overview --- p.1-2 / Chapter Chapter 2: --- Teratogenic Effects of Hyperglycemia / Chapter 2.1 --- What is Hyperglycemia --- p.3 / Chapter 2.2 --- Teratogenic Effects of Hyperglycemia --- p.4-6 / Chapter 2.2.1 --- Human Studies / Chapter 2.2.2 --- Animal Studies / Chapter 2.3 --- Timetables for Embryogenesis: Rats versus Humans --- p.7 / Chapter 2.4 --- Mechanisms of Hyperglycemia Induced Teratogenesis --- p.8-12 / Chapter 2.4.1 --- What are Free Radicals? / Chapter 2.4.2 --- Major Free Radical Species Involvedin Hyperglycemic Teratogenesis / Chapter 2.4.3 --- Molecular Damage Induced by Reactive Oxygen Species / Chapter 2.4.4 --- Supporting Evidence of Reactive Oxygen Species Causing Anomalies / Chapter 2.4.5. --- Hyperglycemia and Formation of Free Radicals / Chapter Chapter 3: --- Caffeine as Teratogen and Antioxidant / Chapter 3.1 --- Popularity of Caffeine --- p.13 / Chapter 3.2 --- Basic Metabolism of Caffeine --- p.14 / Chapter 3.3 --- Biological Actions of Caffeine --- p.15 / Chapter 3.4 --- Teratogenicity of Caffeine --- p.16-20 / Chapter 3.4.1 --- Animal Studies / Chapter 3.4.1.1 --- Teratogenic Effects of Caffeine in Animals / Chapter 3.4.1.2 --- Teratogenic Dose of Caffeine / Chapter 3.4.1.3 --- Interspecies Sensitivity / Chapter 3.4.2 --- Human Studies / Chapter 3.5 --- Possible Mechanisms for the Teratogenic Actions of Caffeine --- p.21 / Chapter 3.6 --- Caffeine as an Antioxidant --- p.22 / Chapter 3.7 --- Combined Effects of Caffeine with Other Substances --- p.23 / Chapter Chapter 4: --- Combined Effects of Hyperglycemia and Caffeine on Early Embryogenesis- A Question to be Answered / Chapter 4.1 --- Possible Links between Hyperglycemia and Caffeine --- p.24 / Chapter 4.2 --- Objectives of the Present Study --- p.25 / Chapter 4.3 --- Hypothesis --- p.26 / Chapter Section II: --- Research Designs and Methods / Chapter Chapter 5: --- Materials and Methods / Chapter 5.1 --- Licenses --- p.27 / Chapter 5.2 --- Overall Study Design --- p.28-40 / Chapter 5.2.1 --- Whole Embryo Culture Model / Chapter 5.2.1.1 --- Animals / Chapter 5.2.1.2 --- Explantation of Embryos and Serum Collection / Chapter 5.2.1.3 --- Preparation of Serum / Chapter 5.2.1.4 --- Culture Media / Chapter 5.2.1.5 --- Embryo Culture / Chapter 5.2.2 --- Experimental Groups / Chapter 5.2.3 --- Morphological Assessment / Chapter 5.2.4 --- Quantitation of Oxidative Stress / Chapter 5.2.5 --- Protein Assay / Chapter 5.3 --- Statistical Evaluation --- p.41 / Chapter Chapter 6: --- Laboratory Considerations / Chapter 6.1 --- Whole Embryo Culture Model --- p.42-43 / Chapter 6.1.1 --- Subjects / Chapter 6.1.2 --- Time Mating / Chapter 6.1.3 --- Culture Medium / Chapter 6.1.4 --- Gas Phase and Rotating Bottle Culture Method / Chapter 6.2 --- Quantification of Oxidative Stress --- p.47-49 / Chapter 6.2.1 --- 8-Isoprostaglandins F2a as a Marker / Chapter 6.2.2 --- Assay for 8-Isoprostaglandins F2a / Chapter 6.2.2.1 --- Enzyme Immunoassay versus Gas Chromatography/ Mass Spectrometry / Chapter Section III: --- Results / Chapter Chapter 7: --- Results / Chapter 7.1 --- Justifications of Methods of Statistical Analysis --- p.50 / Chapter 7.2 --- Effects of Hyperglycemia on Early Embryogenesis --- p.51-56 / Chapter 7.2.1 --- Effects of Hyperglycemia on Morphological Development / Chapter 7.2.2 --- Effects of Hyperglycemia on Production of 8-isoprostaglandins F2a / Chapter 7.2.3 --- Effects of Hyperglycemia on Total Protein Content / Chapter 7.3 --- Effects of Caffeine on Early Embryogenesis --- p.57-61 / Chapter 7.3.1 --- Effects of Caffeine on Morphological Development / Chapter 7.3.2 --- Effects of Caffeine on Total Protein Content / Chapter 7.4 --- Combined Effects of Hyperglycemia and Caffeine on Early Embryogenesis --- p.62-66 / Chapter 7.4.1 --- Combined Effects of Hyperglycemia and Caffeine on Morphological Development / Chapter 7.4.2 --- Combined Effects of Hyperglycemia and Caffeine on Production of 8-isoprostaglandins F2a / Chapter 7.4.3 --- Combined Effects of Hyperglycemia and Caffeine on Total Protein Content / Chapter Section IV: --- Discussion and Conclusions / Chapter Chapter 8: --- Discussion --- p.67-83 / Chapter Chapter 9: --- Conclusions and Future Directions --- p.84 / Appendices --- p.85 / References --- p.86-118

It has been demonstrated that EGCG and caffeine, naturally present in green tea, have thermogenic properties in thermoneutral conditions. The purpose of this study was to quantify the effect of the combined ingestion of EGCG/caffeine on thermogenic responses during a 3h mild cold exposure. Eight healthy males (22± 1 y) were exposed in a randomized, cross over, single blinded fashion to the cold (liquid conditioned suit perfused with 15°C water), after ingesting either a placebo (CON) or an extract of 1600mg of EGCG and 600mg of caffeine (EXP). Thermic, metabolic and electromyographic measurements were monitored at baseline and during cold exposure. After 180min of cold exposure, shivering intensity was significantly reduced by ~32% in EXP condition compared to CON. Area under the curve calculations for total shivering intensity was also reduced by ~21% in EXP (457±99 %MVC.min) compared to CON (361±81 %MVC.min; p=0.007). In contrast, the total area under curve of VO2 was ~25% higher in EXP (33.3±5.5 L O2) compared to CON (25.3±5.1 L O2; p=0.03). Total Heat production (Hprod) also increased by about 11% in the EXP condition (1535±112 kJ) compared to control (1372 ±106 kJ; p=0.002). The decrease in shivering activity combined with an increase in VO2 and Hprod, following the ingestion of EGCG and caffeine in the cold, indicates that nonshivering thermogenesis pathways can be significantly stimulated in adult humans.

The purpose of this study was to examine the effects of the relationship among caffeine consumption, levels of trait anxiety, and the personality factor of introversion/ extraversion on performance. In Phase I of this study, volunteers were screened for introversion/extraversi on using the Eysenck Personality Inventory (EPI) and fhigh/low trait anxiety using the State-Trait Anxiety Inventory (STAI). Based on the results of the two screening instruments the volunteers were categorized as high trait-anxious introverts (HTA/I), low trait-anxious introverts (LTA/I), high trait-anxious extraverts (HTA/E), or low trait-anxious extraverts (LTA/E). Using a table of random numbers, 30 subjects from each category were selected. These subjects were further randomly assigned to one of the two treatment levels of caffeine.In Phase II of this study each of the 120 subjects consumed either two milligrams of caffeine per kilogram of body weight or four milligrams of caffeine per kilogram of body weight in six ounces of Tang. After a 45-minute waiting period for the caffeine to enter the blood system, each subject completed the performance task, a seven-minute modified version of the Digit Symbol Scale (DSS) of the Wechsler Adult Intelliqence Scale (WAIS). The dependent variable was the total number of correct responses out of a possible score of 490.The hypotheses were tested using a Three-Way Analysis of Variance, and the F-test was applied to determine statistical significance. None of the three null hypotheses were rejected.

Seven men were studied during 30 minutes of leg ergometer cycling at approximately 70% V02 max to determine the effects of caffeine ingestion on the utilization of muscle glycogen. A caffeine solution (250 ml; 5 mg/kg body weight) given one hour prior to exercise (CAF trial), decreased the rate of muscle glycogen depletion by 36 + 11.86% (p. .005) as compared to a decaffeinated control trial. During the CAF treatment, there was a 16% increase in serum FFA prior to exercise. Exercise resulted in a removal of FFA from the blood in both trials. Muscle triglyceride levels prior to exercise in the CAF trial were nearly 23% higher than control levels and suggest, that excess FFA present prior to exercise in the CAF trial were esterified into triglyceride. Subsequent post-exercise values indicated a greater utilization of endogenous lipid. A model based on caffeine's stimulatory effects on muscle lipid mobilization and its inhibitory action on muscle phosphorylase a appears to be responsible for the lessened use of muscle glycogen.

It has been demonstrated that EGCG and caffeine, naturally present in green tea, have thermogenic properties in thermoneutral conditions. The purpose of this study was to quantify the effect of the combined ingestion of EGCG/caffeine on thermogenic responses during a 3h mild cold exposure. Eight healthy males (22± 1 y) were exposed in a randomized, cross over, single blinded fashion to the cold (liquid conditioned suit perfused with 15°C water), after ingesting either a placebo (CON) or an extract of 1600mg of EGCG and 600mg of caffeine (EXP). Thermic, metabolic and electromyographic measurements were monitored at baseline and during cold exposure. After 180min of cold exposure, shivering intensity was significantly reduced by ~32% in EXP condition compared to CON. Area under the curve calculations for total shivering intensity was also reduced by ~21% in EXP (457±99 %MVC.min) compared to CON (361±81 %MVC.min; p=0.007). In contrast, the total area under curve of VO2 was ~25% higher in EXP (33.3±5.5 L O2) compared to CON (25.3±5.1 L O2; p=0.03). Total Heat production (Hprod) also increased by about 11% in the EXP condition (1535±112 kJ) compared to control (1372 ±106 kJ; p=0.002). The decrease in shivering activity combined with an increase in VO2 and Hprod, following the ingestion of EGCG and caffeine in the cold, indicates that nonshivering thermogenesis pathways can be significantly stimulated in adult humans.

The work in this dissertation aims to describe a simple new test for odor-recognition memory in rats that can be readily performed and results in an easily observable and lasting form of memory. This test has allowed for the demonstration of ethanol-induced retrograde memory impairments in rats when ethanol is administered during both the consolidation and reconsolidation phases of memory encoding. The observation that a high-dose of ethanol can cause retrograde memory impairments when administered immediately or within hours after learning has taken place is an original finding that may have implications for understanding human blackouts. Furthermore, the finding that ethanol can disrupt the reconsolidation of a previously consolidated memory has not been previously established. It is also demonstrated that caffeine can prevent ethanol’s memory impairing effects, a result that contributes a new piece of evidence for caffeine’s effects on the learning and memory process. This effect has been further investigated mechanistically and attributed to caffeine’s dual role as a phosphodiesterase type 5 inhibitor and adenosine A2A antagonist. Neither of these mechanisms alone appear to be sufficient enough to prevent the retrograde memory impairments seen with ethanol. It is hoped that this test and our findings will prove useful for future investigations into the effects of ethanol on learning and memory and the human phenomenon of alcohol-induced blackouts. / text

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