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。
不仅如此。疾病控制预防中心公布，在1998到2005年间，发生了45起因食用生牛奶或生牛奶奶酪而引起的食源性疾病。1000多人得病；104人被送至医院；2人死亡。
基于这些数字，美国奶制品理事会副主席格雷戈里·米勒最近对《华盛顿邮报》说，饮用生牛奶相当于“玩俄罗斯轮盘赌……为什么你们还要冒那个险呢？”
谁有危险？
卡恩斯对饮用生牛奶的风险持何观点呢？“健康的成年人很可能大多数会遭受轻微的胃部痛苦，”他说，“受到威胁最大的是儿童、老年人、孕妇以及那些免疫缺失的人。他们更容易受感染，因为他们的免疫系统要么未充分形成（儿童），要么未发挥出最大的功效（孕妇和老年人）。”
法伦仍认为美国农业部的细菌检测结果并不具有决定意义。她预言20年后，公立学校将给在校学童提供生牛奶。
或许不会。“对生牛奶的狂热永远都不会彻底消失，”卡恩斯说，“总会有些人对生牛奶的某些神奇品质深信不疑。”
1. craze [kreiz] n. 狂热，流行
2. sidle v. 悄悄地移动
3. pasteurize v. 用巴士杀菌法消毒
4. defy v. 违抗，蔑视
5. swear by 非常信赖某物的功效
6. nutritional adj. 营养的
7. microbe n. 微生物，细菌
8. dairy n. 乳品店
9. bypass v. 绕过；忽视
10. go to any, some, great etc. lengths (to do sth) （为达到某目的）不顾一切, 不遗余力
11. first and foremost 首要地
12. credit v. 把…归功于
13. allergy n. 过敏症
14. braces n. 牙箍
15. proponent n. 支持者，倡导者
16. digestion n. 消化
17. immune adj. 免疫的
18. contend v. 主张，认为
19. lipase n. 脂肪酶
20. phosphatase n. 磷酸酶
21. fortify v. 增加（食物）营养价值
22. calcium n. 钙
23. deactivate v. 使无效，使不活动
24. roulette n. 轮盘赌
25. gastric adj. 胃的
26. pregnant adj. 怀孕的
27. immunocompromised adj. 免疫缺失的
28. vulnerable adj. 易受伤害的
29. conclusive adj. 决定性的，确凿的