孕期多吃鱼对胎儿大脑发育有益

Three-year-olds whose mothers ate more fish while pregnant with them score better on several tests of cognitive function than their peers whose mothers avoided seafood ， a new study shows.However ， . 手
Three-year-oldswhosemothersatemorefishwhilepregnantwiththemscorebetteronseveraltestsofcognitivefunctionthantheirpeerswhosemothersavoidedseafood ， anewstudyshows.However ， theresearchersalsofoundthattheamountofmercuryinawomansbodyrosewiththeamountoffishshehadconsumed--andthatchildrenexposedtomoremercuryperformedworseonthesetests.Basedonthefindings ， theysay ， itspossiblefishcouldhaveevengreaterbrainbenefitsforbabiesifmothers-to-beconsumedseafoodwithlowermercurylevels.
"Recommendationsforfishconsumptionduringpregnancyshouldtakeintoaccountthenutritionalbenefitsoffishaswellasthepotentialharmsfrommercuryexposure ， "Dr.EmilyOkenofHarvardMedicalSchoolinBostonandhercolleagueswriteintheMay15issueoftheAmericanJournalofEpidemiology.
Advisoriesonmercurycontaminationofcertaintypesoflarge ， long-livedfish--includingtunaandswordfish--haveraisedconcernsaboutseafoodconsumptionduringpregnancy ， Okenandherteamnote.Ontheotherhand ， fisharealsothechiefdietarysourceofomega-3fattyacids ， substanceskeytoearlybraindevelopment ， theyadd.
Tobetterunderstandtherisksandbenefitsoffishconsumption ， Okenandherteamsurveyed341mothersabouttheirintakeoffishduringthesecondtrimesterofpregnancy ， andthenhadtheirchildrencompleteabatteryoftestsofcognitivefunctionat3yearsofage.
Onaverage ， womenreportedeating1.5servingsoffisheachweekwhiletheywerepregnant.Theamountofmercurythewomenhadintheirredbloodcellswasdirectlyrelatedtotheamountoffishtheyate.Childrenstestscoresrosewiththeamountoffishtheirmothershadconsumed ， butthosewhosemothershadmoremercuryintheirbodiesperformedlesswellonthetests.
Accountingfortheeffectsofmercuryexposurestrengthenedtheeffectoffishintake ， andviceversa ， theresearchersfound.Benefitswerestrongestforchildrenwhosemothersatemorethantwoservingsaweek.
"Ourfindingthatthebenefitoffishintakeisstrengthenedwithadjustmentformercurylevelssuggeststhatifmercurycontaminationwerenotpresent ， thecognitivebenefitsoffishwouldbegreater ， "Okenandherteamexplain."Maternalconsumptionoffishlowerinmercuryandreducedenvironmentalmercurycontaminationwouldallowforstrongerbenefitsoffishintake."
【孕期多吃鱼对胎儿大脑发育有益】SOURCE:AmericanJournalofEpidemiology ， May15 ， 2008.