9 Side Effects of Too Much Caffeine - Healthline

At toxic levels — especially when taken in a short time — caffeine can start to cause a number of unpleasant side effects: headache, nausea, ... HealthConditionsFeaturedBreastCancerIBDMigraineMultipleSclerosis(MS)RheumatoidArthritisType2DiabetesSponsoredTopicsArticlesAcidRefluxADHDAllergiesAlzheimer's&DementiaBipolarDisorderCancerCrohn'sDiseaseChronicPainCold&FluCOPDDepressionFibromyalgiaHeartDiseaseHighCholesterolHIVHypertensionIPFOsteoarthritisPsoriasisSkinDisordersandCareSTDsDiscoverWellnessTopicsNutritionFitnessSexualHealthMen'sHealthWomen'sHealthMentalHealthSleepOriginalSeriesFreshFoodFastDiagnosisDiariesYou’reNotAlonePresentTenseVideoSeriesYouthinFocusHealthyHarvestNoMoreSilenceFutureofHealthPlanHealthChallengesMindfulEatingSugarSavvyMoveYourBodyGutHealthMoodFoodsAlignYourSpineFindCarePrimaryCareMentalHealthOB-GYNDermatologistsNeurologistsCardiologistsOrthopedistsLifestyleQuizzesWeightManagementAmIDepressed?AQuizforTeensAreYouaWorkaholic?HowWellDoYouSleep?Tools&ResourcesHealthNewsFindaDietFindHealthySnacksDrugsA-ZHealthA-ZConnectFindYourBezzyCommunityBreastCancerInflammatoryBowelDiseasePsoriaticArthritisMigraineMultipleSclerosisPsoriasisFollowusonsocialmediaShopProductsbyConditionInsomniaStressReliefBackPainNeckPainSleepApneaHotSleepersAllergiesPainReliefProductReviewsVitamins&SupplementsSleepMentalHealthNutritionAt-HomeTestingCBDMen’sHealthWomen’sHealthHealthConditionsDiscoverPlanConnectShopSubscribeNutritionHealthyEatingMealPrepVitamins&SupplementsLifestyleDietsWeightManagementConditionsProductsNutritionEvidenceBased9SideEffectsofTooMuchCaffeineByFranziskaSpritzleronAugust14,2017Coffeeandteaareincrediblyhealthybeverages.Mosttypescontaincaffeine,asubstancethatmayboostyourmood,metabolismandmentalandphysicalperformance(1,2,3).Studieshavealsoshownthatit’ssafeformostpeoplewhenconsumedinlow-to-moderateamounts(4).However,highdosesofcaffeinemayhaveunpleasantandevendangeroussideeffects.Researchhasshownthatyourgeneshaveamajorinfluenceonyourtolerancetoit.Somecanconsumemuchmorecaffeinethanotherswithoutexperiencingnegativeeffects(5,6).What’smore,individualswhoaren’tusedtocaffeinemayexperiencesymptomsafterconsumingwhatistypicallyconsideredamoderatedose(4,7).Hereare9sideeffectsoftoomuchcaffeine.ShareonPinterest1.AnxietyCaffeineisknowntoincreasealertness.Itworksbyblockingtheeffectsofadenosine,abrainchemicalthatmakesyoufeeltired.Atthesametime,ittriggersthereleaseofadrenaline,the“fight-or-flight”hormoneassociatedwithincreasedenergy(8).However,athigherdoses,theseeffectsmaybecomemorepronounced,leadingtoanxietyandnervousness.Infact,caffeine-inducedanxietydisorderisoneoffourcaffeine-relatedsyndromeslistedintheDiagnosticandStatisticalManualofMentalDisorders(DSM),whichispublishedbytheAmericanPsychiatricAssociation.Extremelyhighdailyintakesof1,000mgormoreperdayhavebeenreportedtocausenervousness,jitterinessandsimilarsymptomsinmostpeople,whereasevenamoderateintakemayleadtosimilareffectsincaffeine-sensitiveindividuals(9,10).Additionally,modestdoseshavebeenshowntocauserapidbreathingandincreasestresslevelswhenconsumedinonesitting(11,12).Onestudyin25healthymenfoundthatthosewhoingestedapproximately300mgofcaffeineexperiencedmorethandoublethestressofthosewhotookaplacebo.Interestingly,stresslevelsweresimilarbetweenregularandlessfrequentcaffeineconsumers,suggestingthecompoundmayhavethesameeffectonstresslevelsregardlessofwhetheryoudrinkithabitually(12).Nevertheless,theseresultsarepreliminary.Coffee’scaffeinecontentishighlyvariable.Forreference,alarge(“grande”)coffeeatStarbuckscontainsabout330mgofcaffeine.Ifyounoticethatyouoftenfeelnervousorjittery,itmightbeagoodideatolookatyourcaffeineintakeandcutitback.Summary:Althoughlow-to-moderatedosesofcaffeinecanincreasealertness,largeramountsmayleadtoanxietyoredginess.Monitoryourownresponseinordertodeterminehowmuchyoucantolerate.2.InsomniaCaffeine’sabilitytohelppeoplestayawakeisoneofitsmostprizedqualities.Ontheotherhand,toomuchcaffeinecanmakeitdifficulttogetenoughrestorativesleep.Studieshavefoundthathighercaffeineintakeappearstoincreasetheamountoftimeittakestofallasleep.Itmayalsodecreasetotalsleepingtime,especiallyintheelderly(13,14).Bycontrast,lowormoderateamountsofcaffeinedon’tseemtoaffectsleepverymuchinpeopleconsidered“goodsleepers,”oreventhosewithself-reportedinsomnia(15).Youmaynotrealizethattoomuchcaffeineisinterferingwithyoursleepifyouunderestimatetheamountofcaffeineyou’retakingin.Althoughcoffeeandteaarethemostconcentratedsourcesofcaffeine,itisalsofoundinsoda,cocoa,energydrinksandseveraltypesofmedication.Forexample,anenergyshotmaycontainupto350mgofcaffeine,whilesomeenergydrinksprovideasmuchasawhopping500mgpercan(16).Importantly,theamountofcaffeineyoucanconsumewithoutaffectingyoursleepwilldependonyourgeneticsandotherfactors.Inaddition,caffeineconsumedlaterinthedaymayinterferewithsleepbecauseitseffectscantakeseveralhourstowearoff.Researchhasshownthatwhilecaffeineremainsinyoursystemforanaverageoffivehours,thetimeperiodmayrangefromoneandahalfhourstoninehours,dependingontheindividual(17).Onestudyinvestigatedhowthetimingofcaffeineingestionaffectssleep.Researchersgave12healthyadults400mgofcaffeineeithersixhoursbeforebedtime,threehoursbeforebedtimeorimmediatelypriortobedtime.Boththetimeittookallthreegroupstofallasleepandthetimetheyspentawakeatnightincreasedsignificantly(18).Theseresultssuggestthatit’simportanttopayattentiontoboththeamountandtimingofcaffeinetooptimizeyoursleep.Summary:Caffeinecanhelpyoustayawakeduringtheday,butitmaynegativelyimpactyoursleepqualityandquantity.Cutoffyourcaffeineconsumptionbytheearlyafternoontoavoidsleepingproblems.3.DigestiveIssuesManypeoplefindthatamorningcupofcoffeehelpsgettheirbowelsmoving.Coffee’slaxativeeffecthasbeenattributedtothereleaseofgastrin,ahormonethestomachproducesthatspeedsupactivityinthecolon.What’smore,decaffeinatedcoffeehasbeenshowntoproduceasimilarresponse(19,20,21).However,caffeineitselfalsoseemstostimulatebowelmovementsbyincreasingperistalsis,thecontractionsthatmovefoodthroughyourdigestivetract(21).Giventhiseffect,it’snotsurprisingthatlargedosesofcaffeinemayleadtoloosestoolsorevendiarrheainsomepeople.Althoughformanyyearscoffeewasbelievedtocausestomachulcers,alargestudyofmorethan8,000peopledidn’tfindanylinkbetweenthetwo(22).Ontheotherhand,somestudiessuggestthatcaffeinatedbeveragesmayworsengastroesophagealrefluxdisease(GERD)insomepeople.Thisseemstobeespeciallytrueofcoffee(23,24,25).Inasmallstudy,whenfivehealthyadultsdrankcaffeinatedwater,theyexperiencedarelaxationofthemusclethatkeepsstomachcontentsfrommovingupintothethroat—thehallmarkofGERD(25).Sincecoffeecanhavemajoreffectsondigestivefunction,youmaywanttocutbackontheamountyoudrinkorswitchtoteaifyouexperienceanyissues.Summary:Althoughsmalltomoderateamountsofcoffeecanimprovegutmotility,largerdosagesmayleadtoloosestoolsorGERD.Reducingyourcoffeeintakeorswitchingtoteamaybebeneficial.4.MuscleBreakdownRhabdomyolysisisaveryseriousconditioninwhichdamagedmusclefibersenterthebloodstream,leadingtokidneyfailureandotherproblems.Commoncausesofrhabdomyolysisincludetrauma,infection,drugabuse,musclestrainandbitesfrompoisonoussnakesorinsects.Inaddition,therehavebeenseveralreportsofrhabdomyolysisrelatedtoexcessivecaffeineintake,althoughthisisrelativelyrare(26,27,28,29).Inonecase,awomandevelopednausea,vomitinganddarkurineafterdrinking32ounces(1liter)ofcoffeecontainingroughly565mgofcaffeine.Fortunately,sherecoveredafterbeingtreatedwithmedicationandfluids(29).Importantly,thisisalargedosageofcaffeinetoconsumewithinashortperiodoftime,especiallyforsomeonewhoisn’tusedtoitorishighlysensitivetoitseffects.Inordertoreducetheriskofrhabdomyolysis,it’sbesttolimityourintaketoabout250mgofcaffeineperday,unlessyou’reusedtoconsumingmore.Summary:Peoplemaydeveloprhabdomyolysis,orthebreakdownofdamagedmuscle,aftertheyingestlargeamountsofcaffeine.Limityourintaketo250mgperdayifyou’reuncertainofyourtolerance.5.AddictionDespiteallofcaffeine’shealthbenefits,there’snodenyingthatitmaybecomehabit-forming.Adetailedreviewsuggeststhatalthoughcaffeinetriggerscertainbrainchemicalssimilarlytothewaycocaineandamphetaminesdo,itdoesnotcauseclassicaddictionthewaythesedrugsdo(30).However,itmayleadtopsychologicalorphysicaldependency,especiallyathighdosages.Inonestudy,16peoplewhotypicallyconsumedhigh,moderateornocaffeinetookpartinawordtestaftergoingwithoutcaffeineovernight.Onlyhighcaffeineusersshowedabiasforcaffeine-relatedwordsandhadstrongcaffeinecravings(31).Additionally,thefrequencyofcaffeineintakeseemstoplayaroleindependency.Inanotherstudy,213caffeineuserscompletedquestionnairesaftergoing16hourswithoutconsumingit.Dailyusershadgreaterincreasesinheadaches,fatigueandotherwithdrawalsymptomsthannon-dailyusers(32).Eventhoughthecompounddoesnotseemtocausetrueaddiction,ifyouregularlydrinkalotofcoffeeorothercaffeinatedbeverages,there’saverygoodchanceyoumaybecomedependentonitseffects.Summary:Goingwithoutcaffeineforseveralhoursmayleadtopsychologicalorphysicalwithdrawalsymptomsinthosewhoconsumelargeamountsonadailybasis.6.HighBloodPressureOverall,caffeinedoesn’tseemtoincreasetheriskofheartdiseaseorstrokeinmostpeople.However,ithasbeenshowntoraisebloodpressureinseveralstudiesduetoitsstimulatoryeffectonthenervoussystem(33,34,35,36).Elevatedbloodpressureisariskfactorforheartattackandstrokebecauseitmaydamagearteriesovertime,restrictingtheflowofbloodtoyourheartandbrain.Fortunately,caffeine’seffectonbloodpressureseemstobetemporary.Also,itseemstohavethestrongestimpactonpeoplewhoaren’tusedtoconsumingit.Highcaffeineintakehasalsobeenshowntoraisebloodpressureduringexerciseinhealthypeople,aswellasinthosewithmildlyelevatedbloodpressure(37,38).Therefore,payingattentiontothedosageandtimingofcaffeineisimportant,especiallyifyoualreadyhavehighbloodpressure.Summary:Caffeineseemstoraisebloodpressurewhenconsumedathighdosesorpriortoexercise,aswellasinpeoplewhorarelyconsumeit.Butthiseffectmayonlybetemporary,soit’sbesttomonitoryourresponse.7.RapidHeartRateThestimulatoryeffectsofhighcaffeineintakemaycauseyourhearttobeatfaster.Itmayalsoleadtoalteredheartbeatrhythm,calledatrialfibrillation,whichhasbeenreportedinyoungpeoplewhoconsumedenergydrinkscontainingextremelyhighdosesofcaffeine(39).Inonecasestudy,awomanwhotookamassivedoseofcaffeinepowderandtabletsinanattemptedsuicidedevelopedaveryrapidheartrate,kidneyfailureandotherserioushealthissues(40).However,thiseffectdoesn’tseemtooccurineveryone.Indeed,evensomepeoplewithheartproblemsmaybeabletotoleratelargeamountsofcaffeinewithoutanyadverseeffects.Inonecontrolledstudy,when51heartfailurepatientsconsumed100mgofcaffeineperhourforfivehours,theirheartratesandrhythmsremainednormal(41).Regardlessofthemixedstudyresults,ifyounoticeanychangesinyourheartrateorrhythmafterdrinkingcaffeinatedbeverages,considerdecreasingyourintake.Summary:Largedosesofcaffeinemayincreaseheartrateorrhythminsomepeople.Theseeffectsappeartovarygreatlyfrompersontoperson.Ifyoufeelthem,considerreducingyourintake.8.FatigueCoffee,teaandothercaffeinatedbeveragesareknowntoboostenergylevels.However,theycanalsohavetheoppositeeffectbyleadingtoreboundfatigueafterthecaffeineleavesyoursystem.Onereviewof41studiesfoundthatalthoughcaffeinatedenergydrinksincreasedalertnessandimprovedmoodforseveralhours,participantswereoftenmoretiredthanusualthefollowingday(42).Ofcourse,ifyoucontinuetodrinklotsofcaffeinethroughouttheday,youcanavoidthereboundeffect.Ontheotherhand,thismayaffectyourabilitytosleep.Tomaximizecaffeine’sbenefitsonenergyandavoidreboundfatigue,consumeitinmoderateratherthanhighdoses.Summary:Althoughcaffeineprovidesenergy,itcanindirectlyleadtofatiguewhenitseffectswearoff.Aimformoderatecaffeineintaketohelpminimizereboundfatigue.9.FrequentUrinationandUrgencyIncreasedurinationisacommonsideeffectofhighcaffeineintakeduetothecompound’sstimulatoryeffectsonthebladder.Youmayhavenoticedthatyouneedtourinatefrequentlywhenyoudrinkmorecoffeeorteathanusual.Mostresearchlookingatthecompound’seffectsonurinaryfrequencyhasfocusedonolderpeopleandthosewithoveractivebladdersorincontinence(43,44,45).Inonestudy,12youngtomiddle-agedpeoplewithoveractivebladderswhoconsumed2mgofcaffeineperpound(4.5mgperkilogram)ofbodyweightdailyexperiencedsignificantincreasesinurinaryfrequencyandurgency(44).Forsomeoneweighing150pounds(68kg),thiswouldequatetoabout300mgofcaffeineperday.Inaddition,highintakemayincreasethelikelihoodofdevelopingincontinenceinpeoplewithhealthybladders.Onelargestudylookedattheeffectsofhighcaffeineintakeonincontinenceinmorethan65,000womenwithoutincontinence.Thosewhoconsumedmorethan450mgdailyhadasignificantlyincreasedriskofincontinence,comparedtothosewhoconsumedlessthan150mgperday(45).Ifyoudrinkalotofcaffeinatedbeveragesandfeelthatyoururinationismorefrequentorurgentthanitshouldbe,itmaybeagoodideatocutbackonyourintaketoseeifyoursymptomsimprove.Summary:Highcaffeineintakehasbeenlinkedtoincreasedurinaryfrequencyandurgencyinseveralstudies.Reducingyourintakemayimprovethesesymptoms.TheBottomLineLight-to-moderatecaffeineintakeseemstoprovideimpressivehealthbenefitsinmanypeople.Ontheotherhand,veryhighdosagesmayleadtosideeffectsthatinterferewithday-to-daylivingandmightevencauseserioushealthissues.Althoughresponsesvaryfrompersontoperson,theeffectsofhighintakedemonstratethatmoreisn’tnecessarilybetter.Togetthebenefitsofcaffeinewithoutundesirableeffects,conductanhonestassessmentofyoursleep,energylevelsandotherfactorsthatmightbeaffected,andreduceyourintakeifneeded.FEEDBACK:ByFranziskaSpritzleronAugust14,2017ReadthisnextHowYouCanDieFromaCaffeineOverdoseInmoderation,caffeinecanhavebeneficialeffects.Butinlargerdosesitcanputyourhealth,andinrarecases,evenyourlifeatrisk.READMORECoffeeandCaffeine—HowMuchShouldYouDrink?ByKrisGunnars,BScCoffeehasnumeroushealthbenefits,butmanypeoplehaveproblemswithtoomuchcaffeine.Thisarticleexplainshowmuchyoushoulddrink.READMORECaffeineAllergyMedicallyreviewedbyElaineK.Luo,M.D.Ifyouhaveacaffeineallergy,consumingthesmallestamountofcaffeinecanhaveanegativeimpactonyourphysicalandmentalhealth.READMOREWhatIsCaffeine,andIsItGoodorBadforHealth?ByAlinaPetre,MS,RD(NL)Caffeineisanaturalstimulantconsumedthroughouttheworld.Thisarticlereviewscaffeineanditshealtheffects,bothgoodandbad.READMOREWhyIsCoffeeGoodforYou?HereAre7ReasonsByKrisGunnars,BScCoffeewasonceconsideredunhealthy,butnewstudieshaveshowncoffeetohavepowerfulhealthbenefits.Hereare7reasonswhycoffeeisgoodfor…READMOREAmazonFreshReview:Pros,Cons,andHowItComparesByKelliMcGrane,MS,RDAmazonFreshisanonlinegrocerydeliveryservice.Thisarticlereviewsitsprosandcons,howitworks,itsprice,andhowitcompareswithsimilar…READMOREThe15BestFoodSubscriptionBoxestoTryin2022ByRachaelLink,MS,RDFoodsubscriptionboxesareafunandconvenientalternativetogroceryshopping.Seewhichservicesourexpertpickedasthebest.READMORE9oftheBestLowCarbMealDeliveryServicesof2022ByRachaelLink,MS,RDIfyoufollowalowcarbdiet,mealdeliveryservicescanbeagreatoptionwhenyou'reinapinchordon'thavetimetocook.Hereare9ofthetop…READMORE