Got Milk- -有生牛奶吗

GotMilk?|有生牛奶吗？Whatistheyoungmanbuying?Drugs?Stolenelectronics?No.Rawmilk—milkthathasnotbeenpasteurized3.ThesaleofrawmilkisillegalinNewYorkCity.However,someresidentsdefy4thelawtobuythestuff.Theyswearby5itstasteandnutritional6value.Acrossthecountry,otherpeoplearetakingthesamerisktogetrawmilk.Aretheyriskingtheirhealthaswell?CowSharingThemilkthatmostofusdrinktodayispasteurized.Pasteurization,namedafteritsinventor,FrenchchemistLouisPasteur(1822—1895),isaprocessinwhichaliquidisheatedtokillmicrobes7(viruses,bacteria).TheU.S.FoodandDrugAdministration(FDA)bannedthesaleofrawmilkacrossstatelines20yearsago.However,thelegalsaleofrawmilkwithinstatesvariesfromstatetostate.InCalifornia,rawmilkiswidelyavailableonsupermarketshelves.InNewYorkState,residentscanbuyitatonly19approveddairies8.InMaryland,sellingrawmilkisillegal—noexceptions.Inthosestateswhererawmilkisrestrictedorillegal,someresidentsbypass9thelawthrough“cowsharing.”Theybecomepartownersofcowstoacquirerawmilk.Peoplewhogotosuchlengths10claimthatrawmilkhasmorenutrientsandtastesbetterthanthepasteurizedkind.SallyFallonispresidentoftheWestonA.PriceFoundation,whichrunsacampaigncalledRealMilk.“Iamfirstandforemost11amother,”shetoldCurrentScience.“Thisfoundationwasformedwiththeideaofinfantsandchildreninmind.”Shefedherownchildrenrawmilkwheneveritwasavailableandcredits12theirgoodhealth—strongbones,noallergies13,noneedforbraces14—towhatshecalls“thisamazingfood—milk.”Proponents15ofrawmilkandrawmilkproductssaypasteurizationkills“friendly”bacteriathataiddigestion16andstrengthenthebody’simmune17system.Theyalsocontend18thatrawmilkisabettersourceofvitaminB6aswellastheenzymeslipase19andphosphatase20.Anenzymeisaproteinthataidschemicalreactionsinthebody.JeffreyKarns,amicrobiologistattheU.S.DepartmentofAgriculture(USDA),hasadifferenttakeonrawmilk.“Thereisnoproofthatrawmilkisanymorenutritiousthanpasteurizedmilk,”hetoldCurrentScience.“Pasteurizedmilkisusuallyfortified21withvitaminD,whichhelpsthebodyutilizethecalcium22inmilk.Soinsomeways,processedmilkismorenutritiousthanrawmilk.”Karnsaddsthattheenzymecontentofrawmilkandpasteurizedmilkarethesame,thoughtheheatingprocessdeactivates23someenzymesinpasteurizedmilk.Evenifrawmilkhadmoreenzymes,hesays,the“extremelyacid”environmentofthehumanstomachwouldbreakthemdown.RiskandBenefitsFoodscientistshavelongconsideredpasteurizationoneofthegreatadvancesinpublichealth.In1938,beforepasteurizationwaswidelypracticedintheUnitedStates,milkcausedone-quarterofalloutbreaksoffood-andwater-relatedsickness.Thatnumberdroppedtojust1percentby1993,accordingtotheCenterforScienceinthePublicInterest,anutritionadvocacygroup.In2002,theUSDAstudiedrawmilkbyanalyzingsamplesfrom861farmsin26states.Upto23percentoftherawmilksamplesmighthavecontaineddisease-causingformsofbacteria.That’snotall.TheCentersforDiseaseControlandPreventionclaimsthat45outbreaksoffood-bornediseasecausedbyconsumptionofrawmilkorraw-milkcheeseoccurredbetween1998and2005.Morethan1,000peoplebecamesick;104wereadmittedtohospitals;andtwodied.Inlightofsuchnumbers,GregoryMiller,vicepresidentoftheNationalDairyCouncil,recentlytoldTheWashingtonPostthatdrinkingrawmilkis“playingRussianroulette24...Whywouldyoutakethatrisk?”Who’satRisk?WhatisKarns’sopinionabouttherisksofdrinkingrawmilk?“Healthyadultswouldprobablysuffermostlymildgastric25distress,”hesays.“It’skids,elderlyfolks,pregnant26women,andtheimmunocompromised27whoaremostatrisk.Theyaremorevulnerable28toinfectionsbecausetheirimmunesystemsareeithernotfullydeveloped(kids)orarenotfunctioningatmaximumefficiency(pregnantwomenandelderlypeople).”FallonstillbelievesthattheUSDAbacteriatestresultsweren’tconclusive29.Shepredictsthatin20years,publicschoolswillbefeedingrawmilktoschoolchildren.Ornot.“Thiscrazeforrawmilkwillnevercompletelydisappear,”saysKarns.“Therewillalwaysbesomeoneouttherewhobelievesinsomemagicalpropertiesofrawmilk.”一名年轻男子偷偷摸摸地来到纽约市的一个交货点。他把手伸进自己的口袋，从中掏出几张纸币，用这些钱换得一个棕色的纸包。然后，他东张西望地转过身，匆匆离去。这个男子买的是什么？毒品？偷来的电子产品？都不是。是生牛奶——一种没有经巴氏杀菌法消毒的牛奶。在纽约市，销售生牛奶是非法的。然而，一些居民却违反法律去购买这种东西。他们推崇生牛奶的口味和营养价值。在全美各地，还有很多人为了得到生牛奶而甘冒同样的风险。他们是否也在拿自己的健康冒险呢？共享奶牛今天我们大多数人喝的牛奶都是经过巴氏杀菌法消毒过的。“巴氏杀菌法”以其创始人法国化学家路易斯·巴斯德（1822—1895）而得名，是一个将液体加热以杀死其中的微生物（病毒和细菌）的过程。20年前，美国食品药物管理局禁止跨州销售生牛奶。然而，生牛奶的合法销售在不同的州情况各不相同。在加利福尼亚州，生牛奶在超市货架上随处可见。在纽约州，居民只有在19家获准的乳品店才能买得到。在马里兰州，销售生牛奶则是非法的——没有例外。在那些生牛奶受限制或销售不合法的州，一些居民通过“共享奶牛”来绕开法律。他们成为奶牛的部分拥有者，以此来获取生牛奶。这些不择手段的人声称，生牛奶比经过巴氏消毒的牛奶营养更丰富，口味更好。莎莉·法伦是威斯顿·A·普耐斯基金会的主席，该基金会发起一场名为“真牛奶”的运动。“首先，我是一个母亲，”她对《当代科学》杂志说，“设立这个基金会是基于对幼儿和孩子们的考虑。”只要有可能，她就给自己的孩子喝生牛奶，而且，她把他们的健康——强健的骨骼、不过敏、无需戴牙箍——归功于她所称的“神奇食物——牛奶。”生牛奶及其奶制品的倡导者们称巴氏杀菌会杀死一些有助于消化和增强身体免疫功能的“友好”细菌。他们还认为生牛奶是供给维他命B6以及脂肪酶和磷酸酶的更好来源。酶是一种帮助体内化学反应的蛋白质。杰弗里·卡恩斯这位美国农业部的微生物学家对生牛奶则持不同的看法。“没有证据证明生牛奶比消毒牛奶更有营养，”他告诉《当代科学》杂志，“消毒牛奶通常添加有维生素D，可以促进身体利用牛奶中的钙。因此，在某些方面，经过加工的牛奶比生牛奶更有营养。”卡恩斯补充说，生牛奶和消毒牛奶中的酶含量是相等的，虽然加热过程使消毒牛奶中的某些酶失去了活力。即便生牛奶含有更多的酶，他说，人的胃这个“极度酸性”的环境也会将它们分解掉。风险与好处长期以来，食品学家认为巴氏杀菌是公共健康领域的巨大进步之一。1938年，巴氏杀菌法还未在美国得到广泛应用，牛奶引发的疾病占所有与食品和水有关的疾病爆发数的四分之一。据一个营养倡导团体“公共利益科学中心”的统计，到1993年这个数字已下降到仅为1%。2002年，美国农业部通过分析来自26个州861家农场的样品，对生牛奶进行了研究。在这些样品中，多达23%的生牛奶都可能携带致病细菌。不仅如