RED bULL MAY NOT GIVE YOU : RED bULL MAY NOT GIVE YOU : WINGs

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RED bULL MAY NOT GIVE YOU : RED bULL MAY NOT GIVE YOU : WINGs

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• Publié par: idiqizof
• Nombre de lectures: 178
• Langue: Français
• Poids de l'ouvrage: 1 Mo

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 RedBull May Not Give You: A Combination of Caffeine and Taurine Has No Effect on Short Term Memory but Induces Changes in Heart Rate and Mean Arterial Blood Pressure AllisonBichlerandAnnikaSwenson,BS MichelleHarris,PhD n gyloioBuCeroCmulucirr Our Investigation UniversityofWisconsin-Madison

DoesRedBullGiveYouWings? EnergydrinkshaverecentlyexplodedontothemainstreamUSmarketand   arepopularamongstathletes,partygoers,andcollegestudents.otpfotehlsitisAtthe   RedBull,anenergydrinkthatclaimsitsactiveingredients,caffeineandtaurine,“giveyou   wings,”byimprovingperformance,concentrationandreactionspeed,vigilance, emotionalstatus,andstimulatingmetabolism(1)RheT.lulBedetisbewnemmocerds   drinkingRedBullbeforetests,andmanycollegestudentsatUW-Madisonandacrossthe   countrydrinkRedBullwhilestudyingandbeforeexamsbecausetheybelieveitimproves   theirmemoryandperformance. CarefullycontrolledstudiesonRedBull’seffects,particularlyitsinfluenceon   short-termmemory,arelimited.Alford .latehostwjbcenusuhamthatndouf2)( consumedRedBullhadimprovedperformanceonanimmediaterecallmemorytest;   however,anotherstudyindicatedRedBullconsumptionhadnoeffectonhumanverbal   orspatialmemorycomparedtoplacebo(3). ToourknowledgeonlythesetwostudieshaveevaluatedRedBull’seffecton   memory.Neroeithesehtf,seidutserevowhatolis,iderstneevitgnil’ulacsRedBedne,caffei andtaurineemusnocstcejbussttedhasieuddeBlaRcauthteofcan0mla25lluBtohts. energydrink,whichcontainsavarietyofotheringredients,includingglucuronolactone, niacin,vitaminsB6andB12,sucrose,andglucose.tsecffeedinmbcofohteonutydAs   caffeineandtaurinealoneonshort-termexplicitmemoryislacking.

CaffeineEffectsonMemoryareUnclear CaffeineisaCNS-stimulatingdrugthatantagonizesadenosinereceptorsin   thebrain.Thisantagonismhasbeenlinkedtoimprovementinhighercognitivefunctions   suchasmemory(4,5)aeesoftehrletriggersnealsoaCieff.seaucchsrhpenipeihw,eni someofthephysiologicaleffectsassociatedwithcaffeineconsumption,including   increasedheartrateandbloodpressure(6). Aconsensusoncaffeine’simpactonmemoryhasnotyetbeenreached.   Studiesindicatethatcaffeineimprovesreactiontime,endurance,andcognitive   performanceinhumansubjects(4,7,8).Riedel laterompdveineeiffcathatdnuof)5(. bothshortandlongtermmemoryinhumansubjectswithscopolamine-induced   memoryimpairment.tarttdeedssnomhetorwreoceduesingnAionadditcfall,yeawefni ofmemorywithtimeofdayinolderadults(9)usromeNu.se,utidresohtehavver,howe indicatedthatcaffeinehasnosignificantimpactonmemoryfunction(10,11,12).A numberoffactorsmaycontributetothediscrepanciesbetweenstudies,includingthe   timeofdaysubjectsweretested(9,12),thedosageofcaffeineadministered(11),andthe   regularcaffeineusagehabitsoftestsubjects(13). TaurineEffectsonMemoryareAlsoUnclear Taurineisanon-essentialaminoacidthatisfoundinhighconcentrationsin   thebrainandactsasbothaneuromodulatorandneurotransmitter(14,15).Itisalso presentinhighquantitiesinmammalianhearts,whereithasbeenshowntoincrease   cardiacstrokevolume(16)andmayhaveantihypertensiveactivity(14). Itisbelievedtaurinemayplayaroleinmemoryfunctionthroughmodula- tionofN-methyl-D-asparate(NMDA)receptors(17),butnostudiesinhumanshave   establishedaconcretelinkbetweentaurineandmemoryimprovement.utSseidni   mproveschemically-disruptedmemory  

TestingProcedureFe(es.1ig) •Subjectsrestedfor30minutes.   •(etsdatsureminu30ataderaemerewoobldansuesprditgnhaetrrtaeResH1RE,1TMI andMABP1). •Subjectsreceivedtreatmentdrugs:eithercaffeine/taurineorplacebo. •Subjects.llaedowrewequietostudtlyr54yoftusemnitlehiwatretheoottnemtceffek   Duringthistime,theytookashortpracticememorytesttofamiliarizethemselves   withtheformatofthememoryassessment. •Physiologicalparametersweremeasuredagain(PBAMdna2METI2HR,2). •tcidnoittaB,yreomCrapavetirePashorttermbuSxEephtetnlairemscojecttedmple explicitmemorytestinwhichsubjectsrecallrecentlymemorizedrandomfacts.   •Physiologicalparametersweremeasuredforthelasttime(3nadAMEM3,RHTI3BP). •oteaelerewerfjeubsctSvegnitsetdnocesirhetorfekwenatiihdewutnrsrejectSub. sessionandwereadministeredtheothertreatmentdrugandcompletedadifferent   versionofthememoryassessment.

DataAnalysis •Theeffectofcaffeine/taurineonmemorytestscoreswasexaminedusingthe   nonparametricWilcoxonSignedRankstest. •Theeffectofcaffeine/taurineonheartrateandmeanarterialbloodpressuredatawas alsoexaminedusingtheWilcoxonSignedRankstest.

ylladuvidiinymaeinatrunadniefaefaltecrsWthhirccahteeisnedai enhancememory,therearenoknownstudiestodatethathave   investigatedtheircombinedeffectsonshorttermmemoryoftghlinI.   thisresearchvoidandthepopularityofusingRedBullasastudyaid   ontheUWcampus,weinvestigatedwhetherthecaffeineandtaurine   presentinRedBullenergydrinkimproveshorttermexplicit   memory. pmitnousfacnooneaffeiaurindtiennpyheWzesiheotcatthd   concentrationsequivalenttothoseinone250mlservingofRedBull   energydrinkwouldsignificantlyincreaseperformanceonashort   termexplicitmemoryassessmentascomparedtotestperformance   afterconsumingplacebo.estsutIfofredemrcejbpstheontterbet memorytestafterconsumingcaffeineandtaurinecomparedto   placebo,itwouldindicatethatthecombinedneuromodulatory   effectsofthesetwochemicalsdoindeedenhanceshortterm   memory. amnusjbgn14uhbyhavipothesisihtyhsetedetsWaeetplomctsec memoryassessmentontwooccasions:onceafterconsumingcaffeine andtaurinepillsinamountsequivalenttothosefoundinone250ml   RedBullbeverage,andonceafterconsumingaplacebo(sugarpills). Subjectheartrateandbloodpressurewerealsomonitored   throughoutthetrialsinordertoassessthecardiovasculareffectsof   caffeineandtaurineincombination.

00:00 SubjectArrival

Methods

Subjects •Fourteenundergraduatestudentvolunteers(8femaleand 6male),aged18to23 •Nohistoryofheartconditions • Nohistoryoffaelfaneilgereisotcneortauri •Noonoacfusnoitpmtarinureiffoneirrosrphuoe42cto   testing

SubjectTreatment •Eachparticipantreceivedtwodifferenttreatmentsin   randomorderovertwotestingsessions: oActiveTreatment-100mgcaffeineand1000   mgtaurine oPlacebo •Double-blindtreatmentadministration •hefolloTer:daeusermweseretamarpalcigoloisyhpgniw

00:35 SubjectTakesPractice MemoryAssessment

00:40 QuietActivity ofSubjectChoice

00:30 TIME1 Measure HR1 adn MABP1, AdministerTreatment

01:15 TIME2 Measure 2RH dna MABP2, SubjectBeginsMemoryAssessment

01:35 SubjectCompletes MemoryAssessment

01:40 TIME3 Measure 3HR nda MABP3

Figure1.Timeforlineejtcs.buiistngonstsseeentspres0re00:0mieTmoorstteotalvirra’stcejbusttherepresendAMPB1RH1na. firsttimetheseparametersweremeasured30minutesaftersubjectarrival,HR2andMABP2weremeasuredonehourand15minutes afterarrival,HR3andMABP3onehourand40minutesafterarrival.tuni.sednam54oinessscahEournehedolast

 RedBull May Not Give You: A Combination of Caffeine and Taurine Has No Effect on Short Term Memory but Induces Changes in Heart Rate and Mean Arterial Blood Pressure AllisonBichlerandAnnikaSwenson,BS MichelleHarris,PhD BiologyCoreCurriculum UniversityofWisconsin-Madison

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Results

0 1 2 3 4 5 6 7 8 910 11 12 13 14 Subject

Caffeine/Taurine Placebo

Figure2.chEaubsctjer’smentscore(outwammeroysaessseffachtobrednu)leibsspo53ofdtnamtnetreainetaurine/ placeboconditionsonngiserehsawT.netehtecbteewdifferenificanttseirlarosetcs36,(T=iled2-ta)15.0=p.

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HR1/MABP1 (0:30)

HR2/MABP2 (1:15) Time (min)

HR3/MABP3 (1:40)

Figure3.nethcnaegsniheartrateandmeanaretrlaioolbprdsuesorervefthseocourtheuairent/ffieeacneerAvrcpeeag treatmentperiodmeasureBP1werebuejtcsdhwnesretmeatgeinedst.tnAMdna1RH.rofmcaecdifyslaternsde2iRnHgi HR1andMABP3increasedslightlyfromMABP2al.etvreniedcnnoifc5%9antsereeprsrabrorrE.

ShortTermMemory •Caffeine/taurinedidnotsignificantlychangeperformanceonthememory   assessmentascomparedtoplacebo(T=36,2-tailedp=0.506;eseiF.g2). •Subjecttestscoresdidnotimprovewithexperience(nosignificantdifferences intestscoresbetweendaysoneandtwooftesting,T=33.5,p=0.401).

   HeartRate •Significantlydecreasedby~8beats/mininthe45minutesaftercaffeineand   taurinewereingested(comparisonofHR1vs.HR2:T=6,2-tailedp=0.006;see Fig.3).   •Heartrateremainedloweredfortheremainderofthetestingperiod   (comparisonofHR2vs.HR3:T=28.5,2-tailedp=0.233).   •Thesechangeswerenotobservedduringplacebotrials.

MeanArterialBloodPressure •Didnotsignificantlychangeinthe45minutesfollowingcaffeine/taurine   administration(comparisonofMABP1vs.MABP2:T=51,2-tailedp=0.925). •Aslightincreaseof~3mmHgwasobservedaftercompletionofthememory   assessmentyllacitsitatsasawnpNoamar.atthiscatedthtssniidteircet significantincrease(comparisonofMABP2vs.MABP3:T=9,2-tailedp=0.032; seeFig.3). •Thesechangeswerenotobservedduringplacebotrials.

WewouldliketothankBethHalley,AlexLugar,andLauraMannfortheirhelpincompletingthisstudy.We wouldalsoliketoacknowledgeKateColeman,AnnaMomont,SarahSchramm,andJustinSeroyfor   conductingpilotstudies;andDr.BruceBarrett,thesupervisingphysician.tynaMhelleD.rMciahknsot HarrisandtheBiocoreProgramfortheircontinuedsupportofthisresearch.

HR MABP

n CombinationofCaffeineandTaurineDoesNotImproveShortTermMemory

Ourresultsindicatethatacombinationofcaffeineandtaurineinamountssimilartothosein   one250mlservingofRedBullenergydrinkhavenoeffectonshorttermmemoryinyoung   collegestudents.dfeeftccmoibenfeinesofcafcraeserylnoehthetoneatdtohrusOntsresereptudy andtaurineonhumanmemorytneydobehtdutsntv.aiosThtsilerehwmoamynofadison,atUW-M drinkRedBulltoperformbetteronexamsreaulmpltifoereveht,ttaerehmrsfohwoet,deondlbshouIt. memorybesidesshorttermrecall.ofthetypetrthoscaremerelpmiSentapresoftiveyanllmeertob   memorystudentsutilizewhenstudyingforortakingexams.spoItiaocahteltssbiafcofnioatinmbenief andtaurinecanimproveothertypesofmemoryfunction.

CaffeineandTaurineInducedUnexpectedChangesinCardiovascularPhysiology

Whilethemaingoalofourstudywastotesthowacombinationofcaffeineandtaurineimpacted   shorttermmemory,wenotedthedrugshadunexpectedeffectsonheartrateandmeanarterialblood   pressuretbuecrelydcantnifitaetrrhaesadeandtaurinesigitnoofacffieenatthhetomcnabiW.ofednu increasedmeanarterialbloodpressure.  

TaurineMayOverrideEffectsofCaffeineonHeartRate

Subjectheartratesdecreasedby~8beatsperminutewithin45minutesofconsumingcaffeineand   taurine.aelerehfoesersaeehratanrIetsbtygetnriigogecroifnfgeatf,eniwohrevesi,xpeteectodnci epinephrine(19)dceTeheniersartrheamighate.oftaureffectsni.eeorabethteferotdehtirttetub BaumandWeis(16)foundthattaurineincombinationwithcaffeinesignificantlyincreasedcardiac   strokevolumeinyoungenduranceathletesafterexercisemeluvoendaewtebpikortsneereThonshlati. heartratecanbedefinedas: HeartRatexStrokeVolume=CardiacOutput(19) Ifstrokevolumeincreases,cardiacoutputwillincrease,causingmeanarterialbloodpressureto   elevate(CardiacOutputxTotalPeripheralResistance=MABP).ecetdrstoepecorsesaercnitArterialbar inbloodpressureandimmediatelycompensatebytriggeringadecreaseinheartratetoreducecardiac   outputandreturnbloodpressuretonormallevelsthattaurinetrnaontebcreatniWh.cweeileggider thissequenceofevents,thefactthatheartratedidnotincreaseasexpectedwithcaffeineconsumption   suggeststhattaurinewasdoingsomethingtoaltercardiovascularphysiology.

StressMayImpactMeanArterialBloodPressure

Meanarterialbloodpressurehadnotincreased45minutesafterconsumptionofcaffeineandtaurine (immediatelypriortotakingthememoryassessment),butwasslightlyyetsignificantlyelevatedatthe   endofthetestingsessionby~3mmHg,aftersubjectshadcompletedthememorytesthatbeymatI.t: •caffeineandtaurineincombinationwithareleaseofepinephrineduetoastressfulevent(suchas   takingatest)mayelevatebloodpressurehtmeesaeorfsilfussreSt.ggretiroisnuttarelrinenephepi adrenalglands,whichstimulatesvasoconstriction,therebyincreasingbloodpressure(20).As mentionedabove,however,epinephrineshouldalsoinduceanincreaseinheartrate,whichwedid   notobserveinourtrials. •caffeineandtaurineincombinationelevatebloodpressure,buttheeffectoccursmoreslowlythan   thedrugs’actionsonheartrate(i.eretertaemtnwsad45minutesaftRH,.esaercedngiteeswhdeil MABPchangeswerenotobserveduntilafter70minuteshadpassed).  

RecommendationsforFutureStudies

•Havesubjectsrefrainfromcaffeineandtaurineconsumptionforlongerthan24hourspriorto   testingtobetterensurethatsubjectswerefreeofresidualcaffeineandtaurine. •Comparehowcaffeineandtaurineaffecthabitualcaffeineconsumersandnon-users. •TestiftheotheringredientspresentinRedBullenergydrink(glucuronolactoneandothersugars) actinconjunctionwithcaffeineandtaurine(2). •Testtheeffectsofcaffeineandtaurineindividuallyaswellasincombination.

References

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