Does turmeric's reputation translate into real health benefits?

Clinical trials show that curcumin, present in the spice, ... probing through the reams of user data on examine.com – a website that calls ... SkiptomaincontentSkiptonavigationAdvertisementNewsOpinionSportCultureLifestyleShowMoreShowMoreNewsWorldnewsUKnewsCoronavirusClimatecrisisEnvironmentScienceGlobaldevelopmentFootballTechBusinessObituariesOpinionTheGuardianviewColumnistsCartoonsOpinionvideosLettersSportFootballCricketRugbyunionTennisCyclingF1GolfUSsportsCultureBooksMusicTV&radioArt&designFilmGamesClassicalStageLifestyleFashionFoodRecipesLove&sexHealth&fitnessHome&gardenWomenMenFamilyTravelMoneyMakeacontributionSubscribeSearchjobsHolidaysDigitalArchiveGuardianPuzzlesappGuardiancontentlicensingsiteTheGuardianappVideoPodcastsPicturesNewslettersToday'spaperInsidetheGuardianTheObserverGuardianWeeklyCrosswordsFacebookTwitterSearchjobsHolidaysDigitalArchiveGuardianPuzzlesappGuardiancontentlicensingsiteFashionFoodRecipesLove&sexHealth&fitnessHome&gardenWomenMenFamilyTravelMoneyTheObserverMedicalresearchDoesturmeric’sreputationtranslateintorealhealthbenefits?SupermanlogoformedoutofturmericpowderPhotograph:PPartridge/GNMImagingSupermanlogoformedoutofturmericpowderPhotograph:PPartridge/GNMImagingClinicaltrialsshowthatcurcumin,presentinthespice,mayhelpfightosteoarthritisandotherdiseases,butthere’sacatch–bioavailability,orhowtogetitintothebloodDavidCoxSun22May202209.00BSTLastmodifiedonWed25May202208.32BSTWhileKamalPatelwasprobingthroughthereamsofuserdataonexamine.com–awebsitethatcallsitself“theinternet’slargestdatabaseofnutritionandsupplementresearch”–beforeaplannedrevamplaterthisyear,hediscoveredthatthemostsearched-forsupplementonthewebsitewascurcumin,adistinctiveyellow-orangechemicalthatisextractedfromtherhizomesofturmeric,atallplantinthegingerfamily,nativetoAsia.Patelconcludedthatthiswasprobablybecauseofcurcumin’spurportedanti-inflammatoryproperties.“Anastoundingnumberofpeopleexperienceinflammationorhaveinflammation-relatedhealthconditions,andcurcuminandfishoilaretwoofthemostresearchedsupplementsthatcansometimeshelp,”hesays.Thisconsumerinterestincurcuminhasn’tgoneunnoticedbythe“wellness”industry.Besidesitsuseinpillsupplements,curcuminisincreasinglybeingincorporatedintocosmeticproductsthatclaimtohelptreatacneandeczema,preventdryskin,andevenslowdowntheageingprocess.Somereportspredictthattheglobalcurcuminmarketsizecouldreach$191m(£156m)by2028.Thedosesofcurcuminrequiredtogivebenefitareveryhigh–typicallyabout1,000mgadayThegroundrhizomesoftheturmericplantarecommonlyfoundincurrypowder,butturmerichasalsobeenpartofAyurvedicmedicine–atraditionalIndiansystemoftreatment–forcenturies,andatsomepointinthelastdecadeturmericworkeditswayoutofthespicecupboardandtookitsplaceattheforefrontofthewesternwellnessindustry.“AspartofthegeneralconceptofAyurvedicmedicineandwellness,it’sincreasedinpopularityinlockstepwithyogaandmeditation,”saysPatel.Turmerichasbecomethewellnessindustry’snewcure-all.Ithasbeensubjecttoallkindsofwildandwonderfulhealthclaims,includingtheabilitytorelieveallergies,preventcancer,improvehearthealth,reversecognitivedecline,curedepressionandincreaselongevity.Aswithanydietarysupplement,separatingthehypeandthetruthisnotstraightforward,sincenotalltheclaimsaboutturmericarecompletehyperbole.Mostarebasedonthecurcuminturmericcontains,whichhasbeenshowntobeapotentanti-inflammatoryandantioxidant.Rhizomesoftheturmericplant,Curcumalonga,fromagardeninColombo,SriLanka.TheplantisnativetoAsiaandgrowninmanytropicalregions.Photograph:ChamilaKarunarathne/EPAThisiswhereitgetsmorecomplicated.Theproportionofcurcumininturmericisjust3%,byweight.Thescientificstudiesthathavemadepositivehealthassociationsuseeitherpurecurcuminorturmericextractthathasbeendesignedtocontainmostlycurcumin.Thedosesofcurcuminrequiredtogivebenefitareveryhigh–typicallyabout1,000mgaday.Sodespitewhatmanufacturersmightclaim,consumingturmericshotsandlattesoraddingalittleextraspicetoyourmealswillnotcomeclosetoreachingthenecessarydose.Someturmericproductshaveevenbeenfoundtobecontaminatedwithheavymetalssuchaslead,whichcanhaveadverseeffectsonyourhealth.Butthereisgenuineinterestfromscientistsaroundtheworldincurcumin’spotentialasanaturaltreatmentforawholerangeofchronicillnesses.Themostconvincingevidencesofarrelatestoitsabilitytorelievejointpaininpeoplewithosteoarthritis,anareaofmedicinewherethereisahugeunmetneedowingtothelimitationsofnon-steroidalanti-inflammatorydrugs(NSAIDs).“Osteoarthritisisthemostprevalentjointdiseaseworldwide,”saysKristopherPaultre,assistantprofessoroforthopaedicsandfamilymedicineattheUniversityofMiami.“NSAIDshavebeenastapleintreatmentbutarenotwithouttheirdrawbacksincludinggastrointestinal,cardiacandrenalissueswhenusedchronically.”Butthisisjustoneareaofinvestigation.Thereare70clinicaltrialsaroundtheworldthatareeitheractiveorseekingpatients,andarelookingatthepotentialofcurcumintotreatchronickidneydisease,cognitivedecline,irritablebowelsyndrome(IBS),maculardegeneration,andeventoslowdowntheprogressionofvariousformsofcancer.Advancesindrug-deliverytechniquesInthemid1990s,JackArbiserandNancyDeMorewereyoungresearchersatHarvardMedicalSchoolexploringnewtreatmentoptionsforcancer,whentheycameacrosssomeresearchsuggestingthatcurcumincouldinhibitthegrowthofdifferenttypesofcancercellsinatesttube.Intriguedbythis,theywentontofindthatcurcumincouldpreventtheformationofnewbloodvessels,aprocesscalledangiogenesis,whichalltumoursrequiretosustainthemselves.“Togetherweshowedthatcurcumininhibitsangiogenesis,”saysDeMore.“Wewereveryexcitedaboutthisinitialfinding.Therehavesincebeenseveralstudiesusingcurcumininclinicaltrialsinpatientswithpancreaticcancer,breastcancer,andmultiplemyelomashowingthatthereissomebiologiceffect.”AnaerialviewofaturmericfieldinIndia.Photograph:CRShelare/GettyHowever,whenscientistsmovedfromtestingcurcumininthelabtotestingitonhumans,therewasacatch–onethathasdoggedcurcumineversince.Thecompoundhasnotoriouslypoorbioavailability–therateatwhichthebodyabsorbsasubstance–makingitnearlyimpossibletogetsufficientlyhighconcentrationsofcurcuminintothebloodthroughoralsupplementationalone.This,alongwiththecommercialdifficultiesofpatentingnaturalproducts,meantthatscientificinterestincurcuminsoonwaned,andwouldremaininthedoldrumsformorethanadecade.Butinrecentyears,advancesindrugdeliverytechniqueshaverenewedinterestincurcumin.Nanoparticlesystemsarebeingexploredaswaysofpotentiallygettinghighdosesofcurcumintotumours.Someresearchhasshownthatcombiningcurcuminwithpiperine–acompoundfoundinblackpepper–canenhanceitsabsorptionintotheblood,althoughitstillremainstobeprovenwhetherthiscanhelpyieldbenefitinhumans.Whiletherearenowawholevarietyofoff-the-shelfsupplementsthatcombinecurcuminandpiperine,therearestillchallengesforscientistslookingtouseitmedically.Oneoftheseisthatpiperinehasbeenshowntoinhibitavarietyofenzymesthataidinmetabolisingdrugs,anditremainstobeseenwhetherthiscouldcauseanincreasedriskofside-effectsinpatientsalsotakingprescriptionmedicines.Intheworldofsport,curcuminhasgainedareputationasanaidtomusclerehabilitation“Theproblemofcurcumin’sabsorptionhasbeenenthusiasticallyaddressedbyanumberofsupplementcompaniesandresearchers,”saysWyattBrown,aresearcheratexamine.com.“Theytypicallydothisbypackagingitinhighlyabsorbablelipidsofvarioustypessothatmoreofitgetsintothebody.”Thishasbeenacceleratedbyadriveformorenaturalalternativestopainkillers,butalsobythefactthatintheworldofsport,curcuminhasgainedareputationasanaidtomusclerehabilitation.ScientistsatNorthumbriaUniversityareplanningaclinicaltrialtostudythis,whileintheUS,Paultreisalreadywitnessingtheriseofcurcuminasasportssupplement.“Curcuminhasseenasignificantincreaseinuseinathleticsforrecoverypost-workoutsandaftergames,”hesays.“Theideaisthesameaswithosteoarthritisandthegoalistoreduceinflammation.WetendtoavoidchronicNSAIDuseinathletesduetoside-effects.Theevidenceseemstobepositive,butonceagainthereisstillworktobedone.”Turmericlattesarepromotedasahealthyalternativetocoffeebuttheevidenceisquestionable.Photograph:LarisaDuka/AlamyPotentialnewdeliverymethodshavesparkedinterestonceagainincurcumin’spotentialanti-cancerproperties,withvariousresearcherskeentoexploreitsusesinpatientsintheearlystagesofthedisease,asanadd-ontreatmenttomoreconventionalcancerdrugs.DeMore,nowaprofessorofsurgeryattheMedicalUniversityofSouthCarolina,hasreturnedtostudyingcurcuminafteranear20-yeargap,launchingaclinicaltrialtoseewhetherbreastcancerpatientstakingaformulationofcurcuminspeciallydesignedtoenhanceitsabsorptionintothebloodexperienceadecreaseintumourproliferation.Atthesametime,oncologistsattheUniversityofRochesterMedicalCenterinNewYorkstatearerunningatrialtoseewhethercurcuminsupplementedwithpiperinecanhaltdiseaseprogressioninpatientswithlow-gradeprostatecancer,andpreventthemfromrequiringmoreaggressivetreatment.Inbothcases,scientistsarekeentoemphasisethatthesetrialsareverymuchintheexploratorystage,andeveniftheyproducepositiveresults,farmoreproofwillbeneededbeforecurcumincanbeofficiallyrecommendedforcancerpatients.Forexample,evenifthedatafromDeMore’sstudyshowsthatcurcuminappearstoreducetherateatwhichtumoursaregrowing,itwouldthenrequireafullrandomisedcontroltrial–wherecurcuminiscomparedagainstaplacebo–toprovethatitcanactuallyprolongsurvivalorpreventtumourrecurrenceincancerpatientswhohavebeenthroughchemotherapy.Supplementfirmsclaimtohavefixedthecurcuminabsorptionproblemwithpepper,orsoycompounds.Photograph:Pixel-shot/Alamy“Theproblemisthatmanyofthesenaturalproductshavenotbeenthroughthetraditionalclinicaltrialstoevaluatewhetherornottheytrulyareeffective,”saysDeMore.“Ifourtrialshowsbenefits,itwouldallowustowritegrantstofundfurtherrandomisedcontrolledclinicalstudies.”Paultresaysitispositivethatfurtherindependenttrialsarebeingfundedforcurcuminbecausemuchoftheresearchonthecompoundhasbeenacquiredthroughsmallstudiesthathavebeenfinancedbythenutraceuticalindustry,whichhascreatedaperceptionofcurcuminasamiraclecure.“Currentstudiesstillhavealotofpotentialbiasinthem,”hesays.“Nutraceuticalsdonothavemuchregulatoryoversight,andcompanieswanttomakeaprofit.Thereisalwaysconcernforbiasinthesestudies,whichproduceamazingresultswithaspecificproduct.”Whilethereisongoinginterestincurcuminacrossawholespectrumofdiseases,thereisalackofconcreteevidenceforitsbenefitsforconditionssuchascognitivedecline,IBS,orchronicpainbeyondosteoarthritis,whileWyattdescribesanyclaimsthatcurcumincouldmeaningfullyreducetheriskofcardiovasculardiseaseas“speculative”.Cannabishealthproductsareeverywhere–butdotheyliveuptothehype?ReadmoreButtherearehopesthattheanti-inflammatorypropertiesofcurcumincouldofferbenefitsfordepression.LauraFusar-Poli,apsychiatryresearcherattheUniversityofCatania,Italydescribesanumberoftheories,includingthatcurcuminmaybeabletorestorelevelsofserotonininthebrainsofdepressedpatientsandapossiblemodulatoryeffectonthebrain-gutaxis.Buttodate,evidenceofanyofthisinhumansremainsscarce.Paultreishopingthatthecurrentinterestincurcuminwillhelpdevelopagold-standardwayofdeliveringitintothebodyaswellasagreementsonthebestdosetouse,whichcouldallmakeiteasierforscientiststoquantifyitsbenefitsinfuture.“Theproblemisthatthereisnoconsensusonappropriatecurcuminlevelsfortherapeuticeffect,”hesays.“Additionally,withsomanyformulationsoutthere,therearenostudiescomparingthebioavailabilityofeachone.It’sabitlikethewildwestinthisregard.Thereforethoughthereisevidenceofcurcuminbeinghelpfulinsomeconditions,thereisstillalotofworktobedone.”TopicsMedicalresearchTheObserverCancerresearchCancerOsteoarthritisBreastcancerHealthHealth&wellbeingfeaturesReusethiscontentMostpopularMostpopularFashionFoodRecipesLove&sexHealth&fitnessHome&gardenWomenMenFamilyTravelMoney