Turning what was once conventional wisdom on its head, a new study suggests that many, if not most peanut allergies can be prevented by feeding young children food containing peanuts beginning in infancy, rather than avoiding such foods.
与传统观念相反,一项新研究表明,与其完全避免花生,如果从婴儿时期便开始食用含有花生的食物,反而可以防止很多——甚至大多数——花生过敏。
About 2 percent of American children are allergic to peanuts, a figure that has more than quadrupled since 1997 for reasons that are not entirely clear. There have also been big increases in other Western countries. For some people, even traces of peanuts can be life-threatening.
约2%的美国儿童对花生过敏,这个数字比1997年增长了四倍多,原因不甚明确。其他西方国家的花生过敏症也大量增多。对有些人来说,摄入微量花生都可能致命。
An editorial published Monday in The New England Journal of Medicine, along with the study, called the results “so compelling” and the rise of peanut allergies “so alarming” that guidelines for how to feed infants at risk of peanut allergies should be revised soon.
周一,《新英格兰医学杂志》(The New England Journal of Medicine)发表了这项研究和一篇社论。社论称,这些研究结果“十分令人信服”,花生过敏的增多“特别令人担忧”,所以关于应该如何喂养有花生过敏风险的婴儿的指导准则应该立即修正。
The study “clearly indicates that the early introduction of peanut dramatically decreases the risk of development of peanut allergy,” said the editorial, by Dr. Rebecca S. Gruchalla of the University of Texas Southwestern Medical Center and Dr. Hugh A. Sampson of the Icahn School of Medicine at Mount Sinai in New York City. It also “makes it clear that we can do something now to reverse the increasing prevalence of peanut allergy.”
社论称,这项研究“清楚表明,幼儿期摄入花生能极大降低患花生过敏症的风险”。社论作者是得克萨斯大学西南医学中心的丽贝卡·S·格鲁查拉博士(Rebecca S. Gruchalla)和纽约市芒特西奈伊坎医学院的休·A·桑普森博士(Hugh A. Sampson)。社论称,这项研究还“清楚表明,现在我们可以行动起来,逆转花生过敏的增长趋势”。
In the study, conducted in London, infants 4 to 11 months old who were deemed at high risk of developing a peanut allergy were randomly assigned either to be regularly fed food that contained peanuts or to be denied such food. These feeding patterns continued until the children were 5 years old. Those who consumed the foods that had peanuts in them were far less likely to be allergic to peanuts when they turned 5.
这项研究在伦敦进行,研究者在有花生过敏高风险的4至11个月婴儿中进行随机分配,其中一些定期喂食含花生的食物,其余的不喂食这种食物。这种喂养模式一直持续到孩子五岁。那些食用含花生食物的孩子到五岁时对花生过敏的比率大为减少。
Dr. Gideon Lack, a professor of pediatric allergy at King’s College London and the leader of the study, said the common practice of withholding peanuts from babies “could have been in part responsible for the rise in peanut allergies we have seen.”
这项研究的带头人、伦敦大学国王学院的儿科过敏教授吉迪恩·拉克博士(Gideon Lack)说,不让婴儿吃花生的这种常见做法“可能是花生过敏症增多的一个原因”。
Whether infants should be fed peanuts and other foods associated with allergies is one of the most common questions parents ask about introducing solid foods to their children, said Dr. Ruchi Gupta, associate professor of pediatrics at Northwestern University, who was not involved in the study. “And until now most of what we can say is there’s not very conclusive data.”
美国西北大学儿科学副教授鲁奇· 古普塔博士(Ruchi Gupta,她没有参与这项研究)说,婴儿是否应该吃花生或其他与过敏症相关的食物是父母在给孩子添加固体食物时经常询问的一个问题,“直到现在,我们能说的大致上还是,还没有非常确定的数据”。
The American Academy of Pediatrics, in guidelines released in 2000, recommended that peanuts be withheld from children at risk of developing allergies until they were 3 years old.
美国儿科学会在2000年发布的指导准则中建议,为了防范过敏,三岁前不要给孩子吃花生。
In 2008, the academy revised its stance, saying there was no conclusive evidence that avoidance of certain foods beyond 4 to 6 months of age helped stave off allergies, but stopped short of recommending that parents give their young children such foods.
2008年,该学会改变了立场,称没有明确证据证明,在四至六个月年龄段后不食用某些食物能帮助防止过敏,但是也没有建议父母给幼儿喂食这种食物。
“There was no study showing that that was the right thing to do,” said Dr. Wesley Burks, chairman of pediatrics at the University of North Carolina, who was not involved in the new research. Now, with the new study, he said, there is such evidence.
“当时没有任何研究表明,在幼儿时期喂食含花生的食物是正确的,”北卡罗来纳大学儿科学主任韦斯利·伯克斯博士(Wesley Burks,他没有参与这项新研究)说。他说,现在这项新研究提供了证据。
The results of the study were presented on Monday at the annual meeting of the American Academy of Allergy, Asthma and Immunology in Houston.
周一,这项研究的结果在休斯顿的美国过敏、哮喘和免疫学会(American Academy of Allergy, Asthma and Immunology)年度大会上公布。
Pediatricians caution that parents should not feed whole peanuts to infants because of the choking risk, but rather peanut butter or other foods.
儿科医生警告父母们不要给婴儿喂整颗花生,因为有窒息风险,而要喂花生酱或其他花生制品。
Dr. Lack said he first began to question the conventional wisdom about 15 years ago when he gave a talk in Tel Aviv and asked doctors in the audience how many had patients with peanut allergy. Only three hands went up. “In the U.K., if you had asked that question, every single member of the audience would have put up their hand,” he said.
拉克说,他第一次质疑传统观点是在约15年前,当时他在特拉维夫作报告,他问听众中的医生有多少遇到过花生过敏症病人。只有三个人举手。“在英国,如果你问那个问题,所有听众都会举手,”他说。
So Dr. Lack and colleagues conducted a survey, published in 2008, that found the rate of peanut allergy in Israeli children was only about one-tenth that of Jewish children in Britain. The best explanation, they concluded, was that Israeli infants consumed high amount of peanut protein in the first year of life while parents in Britain avoided giving such foods.
所以,拉克和同事们进行了一项调查,调查结果于2008年发表。他们发现,以色列儿童的花生过敏症比率只有英国犹太儿童的约十分之一。他们推断,最可能的原因是,以色列婴儿在头一年中摄入了大量花生蛋白质,而英国父母不给婴儿吃这种食物。
Some other studies have also found that earlier feeding of allergy-inducing foods was associated with lower allergy rates. But such observational studies are not definitive because there could be unexplored factors that account for the differences.
其他一些研究也发现,在幼儿期喂食致敏食物与过敏症比率较低有关。但是这样的观察性研究不具有确定性,因为这种差异可能是其他未知因素造成的。
The new study, by contrast, was a randomized trial in which the only difference between two groups of children was whether they were fed peanut protein. The study, sponsored by the National Institutes of Health and other organizations in the United States and Britain, involved infants 4 to 11 months old deemed to have a high risk of peanut allergy because they already had severe eczema or were allergic to eggs.
相比之下,这项新研究是随机试验,这两组儿童之间的唯一区别是是否食用花生蛋白质。这项研究由美国国家卫生研究院以及美国和英国的其他一些组织赞助。研究对象是有花生过敏高风险的4至11个月大的婴儿,因为他们已经出现严重湿疹或者对鸡蛋过敏。
The infants were given skin-prick tests for peanut allergy. Those already allergic to peanuts were excluded from the study.
研究者对这些婴儿进行了花生过敏皮试。那些已经对花生过敏的婴儿被排除在研究之外。
Some 530 children were did not have peanut allergy on that initial test. Parents of half of them were told to avoid peanuts. The other half were told to feed their children at least six grams of peanut protein per week, the equivalent of about 24 peanuts, spread over three or more meals. The preferred food was Bamba, an Israeli snack made of puffed corn and peanut butter.
约有530名婴儿在初次皮试中没有出现花生过敏。研究者要求其中一半婴儿的父母不要给孩子喂食花生制品,要求另一半父母每周至少给孩子喂食六克花生蛋白质,大约相当于24颗花生,分散在三餐(或更多顿)中食用。研究者推荐的食物是Bamba,它是一种用爆米花和花生酱做成的以色列零食。
The children were given another allergy test when they turned 5. Only 1.9 percent of those who were fed peanuts were allergic to them, compared with 13.7 percent of the children in the group that avoided peanuts.
这些孩子长到五岁时,又进行了一次过敏测试。吃花生的婴儿中只有1.9%对花生过敏,而不吃花生的那组中有13.7%对花生过敏。
An additional 98 infants had a weakly positive test when the study began, suggesting they were on their way to developing a full-fledged allergy. Among those children, only 10.6 percent of those fed food containing peanuts developed that allergy by age 5, far less than the 35.3 percent rate for children whose parents avoided feeding them peanuts.
另有98名婴儿在初次皮试中表现为弱阳性,说明他们正在向全面过敏症发展。在这些孩子中,食用含花生食物的孩子只有10.6%在五岁时出现花生过敏症,这个比率远远低于不吃含花生食物的孩子,后者的比率是35.3%。
“You got a definitive outcome, which I think is a very important thing,” said Dr. James R. Baker Jr., chief executive of FARE, or Food Allergy Research and Education, an advocacy group that helped pay for the study.
“我们得到了确定的结果,我觉得这很重要,”食物过敏研究和教育组织(Food Allergy Research and Education)的负责人小詹姆斯·R·贝克博士(Dr. James R. Baker Jr.)说。该组织是资助这项研究的一个倡议组织。
There are some caveats. Parents knew which group they were in. And the study was done at a single site in London with 75 percent white children. However, the results were the same for the small number of children of other ethnic groups in the study, the researchers said.
其他需要说明的情况是:父母们知道自己在哪个组。这项研究是在伦敦的单个地方进行的,其中75%是白人儿童。不过,研究者说,这项研究中的其他少量族群的结果也是一样的。
Moreover, it is still unknown whether allergies might yet develop if the regular feeding of peanuts stopped. To test this, the children in the study were taken off peanuts after they turned 5 and are being followed for a year.
另外,目前仍不明确的是,如果常规的花生喂养中断,是否仍会发展成过敏症。为了测试这一点,这项研究中的孩子们五岁后中止食用花生,继续观察了一年。
It is also unknown if the same strategy would work with other foods or for children not considered at a high risk of getting a peanut allergy. Some pediatricians said that if feeding peanut foods to children at risk was beneficial, there would be no reason to withhold such food from children not prone to allergies.
还有一点不确定的是,同样的策略是否适用于其他致敏食物或没有花生过敏高风险的儿童。有些儿科医生说,如果给有风险的孩子喂食花生制品是有益的,那么没理由不给不易过敏的儿童吃这些食物。
Changing practice might not be easy. “I do think parents have the highest fear of introducing peanuts,” said Dr. Gupta of Northwestern. Eight years ago, she withheld peanuts from her own baby daughter, who had eczema and was allergic to eggs. The girl developed a peanut allergy.
改变做法可能并不容易。“我确实认为父母们最怕给孩子吃花生,”西北大学的古普塔说。八年前,她不让自己的幼女吃花生,因为女儿已出现湿疹,且对鸡蛋过敏。她女儿后来患上了花生过敏症。
In light of the new study, Dr. Gupta said, “I’m kind of slapping myself on the wrist.”
古普塔说,看到这项新研究,“我有点自责”。