A young man sidles2 up to a drop point in New York City. Reaching into his pocket, he pulls out a few bills and exchanges them for a brown paper bag. Then, looking both ways, he turns and hurries away.
What is the young man buying? Drugs? Stolen electronics? No. Raw milk—milk that has not been pasteurized3.
The sale of raw milk is illegal in New York City. However, some residents defy4 the law to buy the stuff. They swear by5 its taste and nutritional6 value. Across the country, other people are taking the same risk to get raw milk. Are they risking their health as well?

Cow Sharing
The milk that most of us drink today is pasteurized. Pasteurization, named after its inventor, French chemist Louis Pasteur (1822—1895), is a process in which a liquid is heated to kill microbes7 (viruses, bacteria).
The U.S. Food and Drug Administration (FDA) banned the sale of raw milk across state lines 20 years ago. However, the legal sale of raw milk within states varies from state to state. In California, raw milk is widely available on supermarket shelves. In New York State, residents can buy it at only 19 approved dairies8. In Maryland, selling raw milk is illegal—no exceptions.
In those states where raw milk is restricted or illegal, some residents bypass9 the law through“cow sharing.” They become part owners of cows to acquire raw milk.
People who go to such lengths10 claim that raw milk has more nutrients and tastes better than the pasteurized kind. Sally Fallon is president of the Weston A. Price Foundation, which runs a campaign called Real Milk.“I am first and foremost11 a mother,” she told Current Science.“This foundation was formed with the idea of infants and children in mind.” She fed her own children raw milk whenever it was available and credits12 their good health—strong bones, no allergies13, no need for braces14—to what she calls“this amazing food—milk.”
Proponents15 of raw milk and raw milk products say pasteurization kills “friendly” bacteria that aid digestion16 and strengthen the body’s immune17 system. They also contend18 that raw milk is a better source of vitamin B6 as well as the enzymes lipase19 and phosphatase20. An enzyme is a protein that aids chemical reactions in the body.
Jeffrey Karns, a microbiologist at the U. S. Department of Agriculture (USDA), has a different take on raw milk.“There is no proof that raw milk is any more nutritious than pasteurized milk,” he told Current Science.“Pasteurized milk is usually fortified21 with vitamin D, which helps the body utilize the calcium22 in milk. So in some ways, processed milk is more nutritious than raw milk.”
Karns adds that the enzyme content of raw milk and pasteurized milk are the same, though the heating process deactivates23 some enzymes in pasteurized milk. Even if raw milk had more enzymes, he says, the“extremely acid” environment of the human stomach would break them down.

Risk and Benefits
Food scientists have long considered pasteurization one of the great advances in public health. In 1938, before pasteurization was widely practiced in the United States, milk caused one-quarter of all outbreaks of food-and water-related sickness. That number dropped to just 1 percent by 1993, according to the Center for Science in the Public Interest, a nutrition advocacy group.
In 2002, the USDA studied raw milk by analyzing samples from 861 farms in 26 states. Up to 23 percent of the raw milk samples might have contained disease-causing forms of bacteria.
That’s not all. The Centers for Disease Control and Prevention claims that 45 outbreaks of food-borne disease caused by consumption of raw milk or raw-milk cheese occurred between 1998 and 2005. More than 1,000 people became sick; 104 were admitted to hospitals; and two died.
In light of such numbers, Gregory Miller, vice president of the National Dairy Council, recently told The Washington Post that drinking raw milk is “playing Russian roulette24... Why would you take that risk?”

Who’s at Risk?
What is Karns’s opinion about the risks of drinking raw milk?“Healthy adults would probably suffer mostly mild gastric25 distress,” he says.“It’s kids, elderly folks, pregnant26 women, and the immunocompromised27 who are most at risk. They are more vulnerable28 to infections because their immune systems are either not fully developed (kids) or are not functioning at maximum efficiency (pregnant women and elderly people).”
Fallon still believes that the USDA bacteria test results weren’t conclusive29. She predicts that in 20 years, public schools will be feeding raw milk to schoolchildren.
Or not.“This craze for raw milk will never completely disappear,” says Karns.“There will always be someone out there who believes in some magical properties of raw milk.”

一名年輕男子偷偷摸摸地來到紐約市的一個交貨點。他把手伸進自己的口袋，從中掏出幾張紙幣，用這些錢換得一個棕色的紙包。然后，他東張西望地轉過身，匆匆離去。
這個男子買的是什么？毒品？偷來的電子產(chǎn)品？都不是。是生牛奶——一種沒有經(jīng)巴氏殺菌法消毒的牛奶。
在紐約市，銷售生牛奶是非法的。然而，一些居民卻違反法律去購買這種東西。他們推崇生牛奶的口味和營養(yǎng)價值。在全美各地，還有很多人為了得到生牛奶而甘冒同樣的風險。他們是否也在拿自己的健康冒險呢？

共享奶牛
今天我們大多數(shù)人喝的牛奶都是經(jīng)過巴氏殺菌法消毒過的�！鞍褪蠚⒕�法”以其創(chuàng)始人法國化學家路易斯·巴斯德（1822—1895）而得名，是一個將液體加熱以殺死其中的微生物（病毒和細菌）的過程。
20年前，美國食品藥物管理局禁止跨州銷售生牛奶。然而，生牛奶的合法銷售在不同的州情況各不相同。在加利福尼亞州，生牛奶在超市貨架上隨處可見。在紐約州，居民只有在19家獲準的乳品店才能買得到。在馬里蘭州，銷售生牛奶則是非法的——沒有例外。
在那些生牛奶受限制或銷售不合法的州，一些居民通過“共享奶�！眮砝@開法律。他們成為奶牛的部分擁有者，以此來獲取生牛奶。
這些不擇手段的人聲稱，生牛奶比經(jīng)過巴氏消毒的牛奶營養(yǎng)更豐富，口味更好。莎莉·法倫是威斯頓·A·普耐斯基金會的主席，該基金會發(fā)起一場名為“真牛奶”的運動。“首先，我是一個母親，”她對《當代科學》雜志說，“設立這個基金會是基于對幼兒和孩子們的考慮。”只要有可能，她就給自己的孩子喝生牛奶，而且，她把他們的健康——強健的骨骼、不過敏、無需戴牙箍——歸功于她所稱的“神奇食物——牛奶�！�
生牛奶及其奶制品的倡導者們稱巴氏殺菌會殺死一些有助于消化和增強身體免疫功能的“友好”細菌。他們還認為生牛奶是供給維他命B6以及脂肪酶和磷酸酶的更好來源。酶是一種幫助體內化學反應的蛋白質。
杰弗里·卡恩斯這位美國農業(yè)部的微生物學家對生牛奶則持不同的看法�！皼]有證據(jù)證明生牛奶比消毒牛奶更有營養(yǎng)，”他告訴《當代科學》雜志，“消毒牛奶通常添加有維生素D，可以促進身體利用牛奶中的鈣。因此，在某些方面，經(jīng)過加工的牛奶比生牛奶更有營養(yǎng)�！笨ǘ魉寡a充說，生牛奶和消毒牛奶中的酶含量是相等的，雖然加熱過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，他說，人的胃這個“極度酸性”的環(huán)境也會將它們分解掉。

風險與好處
長期以來，食品學家認為巴氏殺菌是公共健康領域的巨大進步之一。1938年，巴氏殺菌法還未在美國得到廣泛應用，牛奶引發(fā)的疾病占所有與食品和水有關的疾病爆發(fā)數(shù)的四分之一。據(jù)一個營養(yǎng)倡導團體“公共利益科學中心”的統(tǒng)計，到1993年這個數(shù)字已下降到僅為1%。
2002年，美國農業(yè)部通過分析來自26個州861家農場的樣品，對生牛奶進行了研究。在這些樣品中，多達23%的生牛奶都可能攜帶致病細菌。
不僅如此。疾病控制預防中心公布，在1998到2005年間，發(fā)生了45起因食用生牛奶或生牛奶奶酪而引起的食源性疾病。1000多人得��；104人被送至醫(yī)院；2人死亡。
基于這些數(shù)字，美國奶制品理事會副主席格雷戈里·米勒最近對《華盛頓郵報》說，飲用生牛奶相當于“玩俄羅斯輪盤賭……為什么你們還要冒那個險呢？”

誰有危險？
卡恩斯對飲用生牛奶的風險持何觀點呢？“健康的成年人很可能大多數(shù)會遭受輕微的胃部痛苦，”他說，“受到威脅最大的是兒童、老年人、孕婦以及那些免疫缺失的人。他們更容易受感染，因為他們的免疫系統(tǒng)要么未充分形成（兒童），要么未發(fā)揮出最大的功效（孕婦和老年人）�！�
法倫仍認為美國農業(yè)部的細菌檢測結果并不具有決定意義。她預言20年后，公立學校將給在校學童提供生牛奶。
或許不會�！皩ι�牛奶的狂熱永遠都不會徹底消失，”卡恩斯說，“總會有些人對生牛奶的某些神奇品質深信不疑�！�

1. craze [kreiz] n. 狂熱，流行
2. sidle   v. 悄悄地移動
3. pasteurize   v. 用巴士殺菌法消毒

4. defy   v. 違抗，蔑視
5. swear by 非常信賴某物的功效
6. nutritional   adj. 營養(yǎng)的
7. microbe   n. 微生物，細菌
8. dairy   n. 乳品店
9. bypass   v. 繞過；忽視
10. go to any, some, great etc. lengths (to do sth) （為達到某目的）不顧一切, 不遺余力
11. first and foremost 首要地
12. credit   v. 把…歸功于
13. allergy   n. 過敏癥
14. braces   n. 牙箍
15. proponent   n. 支持者，倡導者
16. digestion   n. 消化
17. immune   adj. 免疫的
18. contend  v. 主張，認為
19. lipase   n. 脂肪酶
20. phosphatase   n. 磷酸酶
21. fortify   v. 增加（食物）營養(yǎng)價值
22. calcium  n. 鈣
23. deactivate   v. 使無效，使不活動
24. roulette  n. 輪盤賭
25. gastric  adj. 胃的
26. pregnant   adj. 懷孕的
27. immunocompromised   adj. 免疫缺失的
28. vulnerable   adj. 易受傷害的
29. conclusive   adj. 決定性的，確鑿的