Physiological and biochemical effects of conjugated linoleic acid and its use in aquaculture

ReviewsinAquaculture(2010)2,59–72doi:10.1111/j.1753-5131.2010.01021.x

Physiologicalandbiochemicaleffectsofconjugatedlinoleicacidanditsuseinaquaculture

RuiRosa1,AnaM.Andrade2,NarcisaM.Bandarra3andMariaL.Nunes3

1GuiaMarineLaboratory,CentreofOceanography,FacultyofSciences,UniversityofLisbon,Cascais,Portugal2FacultyofHumanKinetics,TechnicalUniversityofLisbon,Portugal

3ResearchUnitofUpgradingofFisheryandFarmedProducts,INRB/IPIMAR,Lisbon,Portugal

Correspondence

´rioMar ´timodaGuia,RuiRosa,Laborato

CentrodeOceanogra a,Faculdadede

nciasdaUniversidadedeLisboa,Av.NossaCie

SenhoradoCabo,939,2750-374Cascais,Portugal.Email:rrosa@fc.ul.pt

Received26May2009;accepted9November2009.

Abstract

Inthepastfewdecades,themajorcompellingforceinthestudyofmarinelipidshasbeentheneedofthedevelopingaquacultureindustrytounderstandthelipidnutritionalrequirementsoffarmed shsoastooptimizeproduction.Atpresent,thereisalsoincreasedinteresttoincludehealth-promotingnutri-ents(nutraceuticals)infarmedfoods,suchasconjugatedlinoleicacid(CLA).Conjugatedlinoleicacid,agroupofpositionalandstereoisomersoflinoleicacid(18:2),actsasagrowthfactortopromotearepartitioningoffattolean,lowerbloodlipids,andshowsanticarcinogenic,hypocholesterolaemicandanti-atherogenicproperties.Inthepresentpaper,wediscusscurrentknowledgeoftheroleofCLAinanimalphysiologyandhealthandreviewadvancesinitsapplicationin shaquaculture.

Keywords:aquaculture,conjugatedlinoleicacid,functionalfood,humanhealth,lipogenesis,nutraceutics.

Introduction

Increasingdemandfor sheryproductscontinuestostim-ulatethefurtherdevelopmentandgrowthofaquaculture(Nayloretal.2000).Atpresent,thisactivityrepresentsalmost40%oftheworld’s shproductionandgiventhepredictedpopulationgrowthoverthenexttwodecades,itisestimatedthatmorethan40milliontonnesofaquaticfoodwillberequiredby2030tomaintaincurrentpercapitaconsumption(FAO2007).Despitepredictionsofagrowingaquacultureindustry,stagnantworldcapture sheriesareprojectedtoleadtoaglobalshortageof shand shproductsinfutureyears,withaconsequentriseinprices.

Itisexpectedthatadvancesandtheapplicationofnewtechnologiesandfarmingpracticeswillacceleratethedevelopmentofaquacultureandincreaseoutputs.Thecurrentuseofbiotechnologyoffersasolutiontomakefarmingandthefoodproductionprocessmoreef cientandcosteffective(Hew&Fletcher2001;Melamedetal.2002).However,theincorporationoftransgenicproductsintothefoodchainhasbeenmetwithmassivecriticismfromboththeenvironmentalandhumanhealthsectors.

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Thecurrentpracticeinintensiveaquaculturesystemsalsoincludestheuseofhighcaloriccommercialdiets(almost20%ofthetotalmassaslipid)asasourceofeas-ilyavailableenergytofarmed sh(Tocher2003;Ngetal.2007).Althoughthesedietsprovidethemostcost-ef cientgrowth,theiruseincreasestheenergystoredinadiposetissue,resultinginexcessfatdeposition(Shearer1994),whichisgenerallynotdesirableinsuchproducts.Thishasraisedconcernsoverpossiblereducedlevelsofhumanhealth-promoting(n-3)highlyunsaturatedfattyacidsinfarmed sh.Asaresult,therehasbeenincreasedinterestinunderstandingthephysiologicalmechanismsthatcontrolenergymetabolismanddeterminelipidandfattyacidhomeostasisin sh(Sargentetal.1999;Tocher2003).Inaddition,thereisademandfortailor-madefarmed shproductsandfunctionalfoodscontainingdie-tarycomponentsthathavebene cialpropertiesbeyondtheirtraditionalnutrientvalue.Conjugatedlinoleicacid(CLA)isanutraceutical(foundindairyproducts)thatiscommonlyusedasadietarysupplement.InterestinCLAhasincreasedinthepastdecadeasaresultofitspotentialbene cialhealtheffects.Conjugatedlinoleicacidactsasagrowthfactor(Chinetal.1994)topromotea

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