美国《大西洋月刊》“转基因食品有非常真实的危险”
【顾秀林按:美国《大西洋月刊》是1857年11月创办的精英刊物(见《南方日报》 2001年4月09日 “《大西洋月刊》——美国精神的觉醒 ”介绍)。2012年1月12日,该刊刊登了题为《转基因食品有非常真实的危险(The Very Real Danger of Genetically Modified Foods )》一文;下面是我的译文、英文原文及几点感想。
此文并没有明确、具体地说,那些“非常真实的危险”具体表现为什么,正如南京大学的报告没有讨论,微小核糖核酸(miRNA)的跨界信息交流功能,同转基因食品安全性有什么直接的关系。但是,此文明明白白地暗示,用“敲除”一个RNA的方法,可以开发杀虫转基因植物,“孟山都公司把RNA(核糖核酸)干扰原理用于杀虫了,而那个能致死昆虫的生物学机理,在人类身上也是同样存在的”!
在中国突然出现的广泛的、高比率的不孕不育现象,难道就不能给人们一点警示?难道是还想看见更“真实”的、更明确的危险?那该是一个什么样的“非常真实的危险”?在统计上还必须很显著吧?
下面是中英对照译文。谢谢沈阳提出的修订意见。
By Ari LeVaux
Jan 9 2012, 7:57 AM ET457
最新研究表明:我们在食用食物的时候不仅仅是吸收了维他命和蛋白质,而且还摄取了生命信息和微核糖核酸。
New research shows that when we eat we're consuming more than just vitamins and protein. Our bodies are absorbing information, or microRNA.
感谢Christie Wilcox和Emily Willingham分别发表在“科学美国人”博客网和《生物档案》上的科学和生物学博文,介绍阿里·勒沃( Ari LeVaux')在最近的《昙花一现》专栏中指出的“科学中的非自洽”。这篇文章已为多家报社和杂志网站所转载了。这个专栏是为Alternet做的扩展和更新,勒沃在评论栏中做了进一步润色。
Update 1/12: Thanks to science and biology bloggers, Christie Wilcox and Emily Willingham at the Scientific American blog network and The Biology Files, respectively, we've learned of the scientific inconsistencies made in Ari LeVaux's most recent Flash in the Pan column, which is syndicated by a number of newspapers and magazine websites. This column has been expanded and updated for AlterNet, with LeVaux discussing specific improvements in the comments.
在食用大米的人体血液和器官中,中国的研究人员已经找到了一种来自大米的微小核糖核酸片段。这个以南京大学为基地的研究团队称:这种遗传物质会粘附在受体的肝脏细胞上,并且左右人体从血液中清除胆固醇。
Chinese researchers have found small pieces of rice ribonucleic acid (RNA) in the blood and organs of humans who eat rice. The Nanjing University-based team showed that this genetic material will bind to receptors in human liver cells and influence the uptake of cholesterol from the blood.
此种核糖核酸因其本身非常小,被称作微小核糖核酸(缩写为miRNA)。miRNA是在十年前才被发现的,之后进行了广泛研究,并且己被确认为是癌症、老年痴呆症和糖尿病等多种人类疾病的诱因。这些miRNA通过压制或关闭特定基因来发挥作用。中国专家的研究,首次展示了植物中的微小核糖核酸能通过人类消化道而不被降解、首次找到了这些来自植物组织的活性微小生物基因信息物质对人类细胞发号施令的例子。
The type of RNA in question is called microRNA (abbreviated to miRNA) due to its small size. MiRNAs have been studied extensively since their discovery ten years ago, and have been implicated as players in several human diseases including cancer, Alzheimer's, and diabetes. They usually function by turning down or shutting down certain genes. The Chinese research provides the first in vivo example of ingested plant miRNA surviving digestion and influencing human cell function in this way.
如果该研究中的关键点能通过严格的科学评审------它将会颠覆许多的研究研究。因为它意味着,我们吃下去的不只是维生素、蛋白质和能量,可能还包含有基因调控因子。
Should the research survive scientific scrutiny -- a serious hurdle -- it could prove a game changer in many fields. It would mean that we're eating not just vitamins, protein, and fuel, but gene regulators as well.
That knowledge could deepen our understanding of many fields, including cross-species communication, co-evolution, and predator-prey relationships. It could illuminate new mechanisms for some metabolic disorders and perhaps explain how some herbal and modern medicines function.
中国专家的这项研究本身未涉及转基因食品问题,其实它对此有更大的价值。这项研究为我们打开了眼界,展现了一条认识新食品如转基因食品如何影响人类健康的新途径,这是我们完全没有意料到的。
This study had nothing to do with genetically modified (GM) food, but it could have implications on that front. The work shows a pathway by which new food products, such as GM foods, could influence human health in previously unanticipated ways.
在孟山都公司的官方网站上,有这样的宣告:“测试转基因食品对人类的安全性是完全没有必要、也没有意义的”。这是一个有利于商业的说法,它依据的基础是1960年前后的遗传学。它遵循的是被称为“中心法则”的遗传学,中心法则假说是这样的:是DNA在主导细胞;从DNA到细胞之间存在一种单方向运行的指令控制链。
Monsanto's website states, "There is no need for, or value in testing the safety of GM foods in humans." This viewpoint, while good for business, is built on an understanding of genetics circa 1960. It follows what's called the "Central Dogma" of genetics, which postulates a one-way chain of command between DNA and the cells DNA governs.
“中心法则”——这事很像我们在比萨饼店订购一个比萨饼的过程:在这里,DNA(脱氧核糖核酸Deoxyribonucleic acid的英文缩写)是指所要的比萨饼类型;下的那个订单叫RNA(核糖核酸 Ribonucleic acid英文缩写),订单指示厨师所定制的比萨饼有什么特点。随后烤好交货的比萨饼,就是DNA所编码合成的那个“蛋白质”。
The Central Dogma resembles the process of ordering a pizza. The DNA codes for the kind of pizza it wants, and orders it. The RNA is the order slip, which communicates the specifics of that pizza to the cook. The finished and delivered pizza is analogous to the protein that DNA codes for.
几十年来,科学家们越来越明白,“中心法则”理论只是在大体上正确,它太过简化了。例如不执行编码过程的微小核糖核酸miRNA,并不编码烤制比萨饼的指令、也不干什么事,却能在细胞中移动、并把某些人体的基因表达“沉默”掉。因此,当一段DNA片段在订制一个比萨饼时,它同时有可能攻击带有某个RNA信号的另一家比萨饼店。结果有可能是:别的DNA片段定制的另外的一个比萨饼订单,最终无法完成。
We've known for decades that the Central Dogma, though basically correct, is overly simplistic. For example: MiRNAs that don't code for anything, pizza or otherwise, travel within cells silencing genes that are being expressed. So while one piece of DNA is ordering a pizza, it could also be bombarding the pizzeria with RNA signals that can cancel the delivery of other pizzas ordered by other bits of DNA.
科学家们已经在利用这个发现了。他们可以合成一个几乎与miRNA一模一样的小型人工RNA链。通过一种叫作RNA干扰或RNA“敲除”的方法,这些RNA微小片段就能被用来关闭或者“敲除”特定的基因。
Researchers have been using this phenomena to their advantage in the form of small, engineered RNA strands that are virtually identical to miRNA. In a technique called RNA interference, or RNA knockdown, these small bits of RNA are used to turn off, or "knock down," certain genes.
在1994年,RNA敲除方法第一次用于制造商品,开发出来的是一种保鲜期较长的转基因西红柿——“莎佛”(Flavor Savr)。从2007年以来,多个研究团队报告过,通过敲除特定RNA,己开发成功具有杀虫功能的植物RNA。2007年11月5日,发表在麻省理工学院的《科技评论》杂志上的报告说,中国的研究人员利用RNA敲除法,开发了一种转基因棉花:
RNA knockdown was first used commercially in 1994 to create the Flavor Savr, a tomato with increased shelf life. In 2007, several research teams began reporting success at engineering plant RNA to kill insect predators, by knocking down certain genes. As reported in MIT's Technology Review on November 5, 2007, researchers in China used RNA knockdown to make:
棉花植株中的一种基因被“沉默”了,这种基因原来的功能,是让棉铃虫产生消化棉花中的天然棉酚毒素的能力。吃了基因“沉默”的转基因棉花的棉铃虫,因为不能产生处理毒素的蛋白质而致死。
...cotton plants that silence a gene that allows cotton bollworms to process the toxin gossypol, which occurs naturally in cotton. Bollworms that eat the genetically engineered cotton can't make their toxin-processing proteins, and they die.
And:
另外
还有孟山都和一家比利时公司(Devgen)的研究人员用基因沉默的办法开发出一种转基因玉米,它可以干扰玉米根叶甲虫消化吸收能量所必须的某种基因,令这种昆虫在12天内死亡。
Researchers at Monsanto and Devgen, a Belgian company, made corn plants that silence a gene essential for energy production in corn rootworms; ingestion wipes out the worms within 12 days.
人类和昆虫在基因方面有很多相同之处。假如miRNA的确够通过消化道而存活,那么能够影响昆虫基因调控的miRNA,完全有可能,也会如此影响人类的基因。
Humans and insects have a lot in common, genetically. If miRNA can in fact survive the gut then it's entirely possible that miRNA intended to influence insect gene regulation could also affect humans.
孟山都公司声称,转基因食品“没有必要做人体毒理学测试”,它的根据是“实质性等同”。根据它这个说法,转基因和非转基因农作物之间做比较,只需要检测那个外源DNA本身表达的最终产物(新烤的比萨饼)。孟山都公司认为,那个新插入的DNA不会构成除此“比萨饼”以外的任何问题。
Monsanto's claim that human toxicology tests are unwarranted is based on the doctrine of "substantial equivalence." According to substantial equivalence, comparisons between GM and non-GM crops need only investigate the end products of DNA expression. New DNA is not considered a threat in any other way.
孟山都公司网站上是这样说的:“只要引入的那个蛋白质被认为是安全的,转基因的农产品就被认为在实质上等同,不会对健康构成任何威胁”。
"So long as the introduced protein is determined to be safe, food from GM crops determined to be substantially equivalent is not expected to pose any health risks," reads Monsanto's website.
孟山都公司的意思就是说,只要转基因的最终产物——那个比萨饼——没有毒性,那么外来的DNA就算是没有差异,也不会造成任何食品安全问题。在这里,非常需要指出的一点是,如果把这一法则(实质性等同)用于知识产权法,那么孟山都公司的许多专利应该是不能成立的。
In other words, as long as the final product -- the pizza, as it were -- is non-toxic, the introduced DNA isn't any different and doesn't pose a problem. For what it's worth, if that principle were applied to intellectual property law, many of Monsanto's patents would probably be null and void.
中国RNA(核糖核酸)研究的领衔研究员是张辰宇。他并没有评论他的工作会如何影响转基因食品安全性的争论。但是,这项发现让公众都对孟山都公司的“实质性等同”深感忧虑。而事实上,在很多年前,科学共同体中就提出了这个危害性问题。
Chen-Yu Zhang, the lead researcher on the Chinese RNA study, has made no comment regarding the implications of his work for the debate over the safety of GM food. Nonetheless, these discoveries help give shape to concerns about substantial equivalence that have been raised for years from within the scientific community.
一批科学家1999年就向著名的《自然》杂志写过一封信,题为《在实质性等同的背后》。埃里克·米尔斯通等人在这封信中指出:“‘实质性等同’是一个‘伪科学概念’,在本质上是反对科学的,因为把它提出来只是为不做生物化学检验或毒理学检验找了个借口。”
In 1999, a group of scientists wrote a letter titled "Beyond Substantial Equivalence" to the prestigious journal Nature. In the letter, Erik Millstone et. al. called substantial equivalence "a pseudo-scientific concept" that is "inherently anti-scientific because it was created primarily to provide an excuse for not requiring biochemical or toxicological tests."
对于科学家的指控,孟山都公司是这样回应的:“在1991年的时候,‘实质等同性原则’这一概念在一个由‘经济合作与发展组织(OECD)’所召开的国际科学专家会议上制定了细节。那是早在生物工程产品还没有上市之前的事情了。”
To these charges, Monsanto responded: "The concept of substantial equivalence was elaborated by international scientific and regulatory experts convened by the Organization for Economic Co-operation and Development (OECD) in 1991, well before any biotechnology products were ready for market."
孟山都公司这个回应,在表面上是反驳一项指责,实际上它是把这件事处理成一项监管性事务了。“实质上等同”显然需要在孟山都公司的转基因产品上市之前提出。这是为它的转基因食品全球化商业所做的一项政策准备。我们都己看见:在世界上任何一个地方,只要接受了“实质等同性”原则,转基因食品市场销售的准入合法性便顺理成章地办妥了。当“实质性等同”被世界采纳时,孟山都公司已经种出大量转基因农产品,不失时机地把它们包装起来推向市场了。
This response is less a rebuttal than a testimonial to Monsanto's prowess at handling regulatory affairs. Of course the term was established before any products were ready for the market. Doing so was a prerequisite to the global commercialization of GM crops. It created a legal framework for selling GM foods anywhere in the world that substantial equivalence was accepted. By the time substantial equivalence was adopted, Monsanto had already developed numerous GM crops and was actively grooming them for market.
拥有34个成员国的经济合作与发展组织(OECD),主要是发达、富裕、以白人为主的国家,而且是“亲”大公司的。这个组织有一个使命,把经济发展推延到世界上的每一个角落。在这项使命的推进当中,OECD的确为孟山都公司向全球推广“实质性等同”助了一臂之力。
The OECD's 34 member nations could be described as largely rich, white, developed, and sympathetic to big business. The group's current mission is to spread economic development to the rest of the world. And while the mission has yet to be accomplished, OECD has helped Monsanto spread substantial equivalence globally.
许多转基因食品的支持者喜欢说:如果必须测试转基因食品的毒性,那么对世界上的全部食品都应该做毒性测试。
Many GM fans will point out that if we do toxicity tests on GM foods, we should also have to do toxicity testing on every other kind of food in the world.
可是,现有一切食物植物的毒性?——测试早就做完了。我们做了几千年艰难的测试,我们试尝陌生的植物,导致有人死亡、或者濒临死亡。我们就是这样学会的识别有毒植物。我们每一个人都在以一生的时间不断地确认,我们究竟会对哪些食物过敏。
But we've already done the testing on the existing plants. We tested them the hard way, by eating strange things and dying, or almost dying, over thousands of years. That's how we've figured out which plants are poisonous. And over the course of each of our lifetimes we've learned which foods we're allergic to.
我们食用的一切非转基因的或杂交品种的植物,它们的遗传特性都包容在各自的父母亲本中,而它们的基因足够相似,以使它们能够通过固有的交配方式、嫁接方式甚至人工受精(试管)方式,繁育和它们自己相似的后代。
All of the non-GM breeds and hybrid species that we eat have been shaped by the genetic variability offered by parents whose genes were similar enough that they could mate, graft, or test tube baby their way to an offspring that resembled them.
给我吃一颗转入了鱼类基因的土豆?且慢。对我来说,那是一种新型植物,需要做测试。今天的科学是多么的新奇;新植物有没有有毒、会不会造成过敏,我们可不能用老掉牙的方法去察看它。
A tomato with fish genes? Not so much. That, to me, is a new plant and it should be tested. We shouldn't have to figure out if it's poisonous or allergenic the old fashioned way, especially in light of how new-fangled the science is.
时光流转,物换星移。承认眼前的事实吧:改写转基因知识蓝本的时刻已经到来!基因系统的复杂性超过我们的监管系统千百倍,比制定这些规则的公司更复杂千百倍。
It's time to re-write the rules to acknowledge how much more complicated genetic systems are than the legal regulations -- and the corporations that have written them -- give credit.
孟山都公司说“测试转基因食品对人类健康的安全性,既没必要也没有价值”,无助于提升该公司的公众形象。应该承认,食品安全性测试很不好做,因为没有哪一个人愿意,去吃一盘转基因玉米,只是为了证明转基因食品对人类健康有害,或者无害?真正的问题是:孟山都公司把RNA(核糖核酸)干扰原理用于杀虫了,而那个能致死昆虫的生物学机理,在人类身上也是同样存在的。这样的话,在实验室先做个安全测试,就是十分必要的了。
Monsanto isn't doing itself any PR favors by claiming "no need for, or value in testing the safety of GM foods in humans." Admittedly, such testing can be difficult to construct -- who really wants to volunteer to eat a bunch of GM corn just to see what happens? At the same time, if companies like Monsanto want to use processes like RNA interference to make plants that can kill insects via genetic pathways that might resemble our own, some kind of testing has to happen.
应该从这里开始:测试异源DNA被插入后导致的其他后果,如miRNA,而不是仅限于那块预期的“比萨饼”。但是在孟山都公司网站上,我们看到的却是:
A good place to start would be the testing of introduced DNA for other effects -- miRNA-mediated or otherwise -- beyond the specific proteins they code for. But the status quo, according to Monsanto's website, is:
“对转基因农作物中的外源DNA不必做安全性测试。因为所有的食物中都有DNA(以及相应的RNA)。DNA自身是无毒的、在植物中也无毒,不会构成威胁。”
There is no need to test the safety of DNA introduced into GM crops. DNA (and resulting RNA) is present in almost all foods. DNA is non-toxic and the presence of DNA, in and of itself, presents no hazard.
在我们已知的事实目前,孟山都公司太傲慢了。时间将会证明,它这个行为太过轻率。
Given what we know, that stance is arrogant. Time will tell if it's reckless.
There are computational methods of investigating whether unintended RNAs are likely to be knocking down any human genes. But thanks to this position, the best we can do is hope they're using them. Given it's opposition to the labeling of GM foods as well, it seems clear that Monsanto wants you to close your eyes, open your mouth, and swallow.
此时此刻,孟山都公司应该做的事情,是如实公告,它对转基因食品安全性所知很少。DNA编码不仅可以合成蛋白质,更有相当多未知功能。RNA的功能很复性,不是当年发现DNA/RNA结构的沃森和克拉克两位科学家所能想象的。
It's time for Monsanto to acknowledge that there's more to DNA than the proteins it codes for -- even if it's for no other reason than the fact that RNA alone is a lot more complicated that Watson and Crick could ever have imagined.
Image: Dirk Ercken/Shutterstock.
The current version of this article originally appeared on AlterNet.
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