給嬰兒吃花生製品能預防花生過敏

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.

與傳統觀念相反，一項新研究表明，與其完全避免花生，如果從嬰兒時期便開始食用含有花生的食物，反而可以防止很多——甚至大多數——花生過敏。

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.

約2%的美國兒童對花生過敏，這個數字比1997年增長了四倍多，原因不甚明確。其他西方國家的花生過敏症也大量增多。對有些人來說，攝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.

週一，《新英格蘭醫學雜誌》(The New England Journal of Medicine)發表了這項研究和一篇社論。社論稱，這些研究結果“十分令人信服”，花生過敏的增多“特別令人擔憂”，所以關於應該如何餵養有花生過敏風險的嬰兒的指導準則應該立即修正。

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.”

社論稱，這項研究“清楚表明，幼兒期攝入花生能極大降低患花生過敏症的風險”。社論作者是得克薩斯大學西南醫學中心的麗貝卡·S·格魯查拉博士(Rebecca S. Gruchalla)和紐約市芒特西奈伊坎醫學院的休·A·桑普森博士(Hugh A. Sampson)。社論稱，這項研究還“清楚表明，現在我們可以行動起來，逆轉花生過敏的增長趨勢”。

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.

這項研究在倫敦進行，研究者在有花生過敏高風險的4至11個月嬰兒中進行隨機分配，其中一些定期餵食含花生的食物，其餘的不餵食這種食物。這種餵養模式一直持續到孩子五歲。那些食用含花生食物的孩子到五歲時對花生過敏的比率大爲減少。

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.”

這項研究的帶頭人、倫敦大學國王學院的兒科過敏教授吉迪恩·拉克博士(Gideon Lack)說，不讓嬰兒吃花生的這種常見做法“可能是花生過敏症增多的一個原因”。

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.”

美國西北大學兒科學副教授魯奇· 古普塔博士（Ruchi Gupta，她沒有參與這項研究）說，嬰兒是否應該吃花生或其他與過敏症相關的食物是父母在給孩子添加固體食物時經常詢問的一個問題，“直到現在，我們能說的大致上還是，還沒有非常確定的數據”。

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.

美國兒科學會在2000年發佈的指導準則中建議，爲了防範過敏，三歲前不要給孩子吃花生。

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，該學會改變了立場，稱沒有明確證據證明，在四至六個月年齡段後不食用某些食物能幫助防止過敏，但是也沒有建議父母給幼兒餵食這種食物。

“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.

“當時沒有任何研究表明，在幼兒時期餵食含花生的食物是正確的，”北卡羅來納大學兒科學主任韋斯利·伯克斯博士（Wesley Burks，他沒有參與這項新研究）說。他說，現在這項新研究提供了證據。

The results of the study were presented on Monday at the annual meeting of the American Academy of Allergy, Asthma and Immunology in Houston.

週一，這項研究的結果在休斯頓的美國過敏、哮喘和免疫學會(American Academy of Allergy, Asthma and Immunology)年度大會上公佈。

Pediatricians caution that parents should not feed whole peanuts to infants because of the choking risk, but rather peanut butter or other foods.

兒科醫生警告父母們不要給嬰兒喂整顆花生，因爲有窒息風險，而要喂花生醬或其他花生製品。

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.

拉克說，他第一次質疑傳統觀點是在約15年前，當時他在特拉維夫作報告，他問聽衆中的醫生有多少遇到過花生過敏症病人。只有三個人舉手。“在英國，如果你問那個問題，所有聽衆都會舉手，”他說。

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，拉克和同事們進行了一項調查，調查結果於2008年發表。他們發現，以色列兒童的花生過敏症比率只有英國猶太兒童的約十分之一。他們推斷，最可能的原因是，以色列嬰兒在頭一年中攝入了大量花生蛋白質，而英國父母不給嬰兒吃這種食物。

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.

其他一些研究也發現，在幼兒期餵食致敏食物與過敏症比率較低有關。但是這樣的觀察性研究不具有確定性，因爲這種差異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，這項新研究是隨機試驗，這兩組兒童之間的唯一區別是是否食用花生蛋白質。這項研究由美國國家衛生研究院以及美國和英國的其他一些組織贊助。研究對象是有花生過敏高風險的4至11個月大的嬰兒，因爲他們已經出現嚴重溼疹或者對雞蛋過敏。

The infants were given skin-prick tests for peanut allergy. Those already allergic to peanuts were excluded from the study.

研究者對這些嬰兒進行了花生過敏皮試。那些已經對花生過敏的嬰兒被排除在研究之外。

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.

約有530名嬰兒在初次皮試中沒有出現花生過敏。研究者要求其中一半嬰兒的父母不要給孩子餵食花生製品，要求另一半父母每週至少給孩子餵食六克花生蛋白質，大約相當於24顆花生，分散在三餐（或更多頓）中食用。研究者推薦的食物是Bamba，它是一種用爆米花和花生醬做成的以色列零食。

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.

這些孩子長到五歲時，又進行了一次過敏測試。吃花生的嬰兒中只有1.9%對花生過敏，而不吃花生的那組中有13.7%對花生過敏。

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名嬰兒在初次皮試中表現爲弱陽性，說明他們正在向全面過敏症發展。在這些孩子中，食用含花生食物的孩子只有10.6%在五歲時出現花生過敏症，這個比率遠遠低於不吃含花生食物的孩子，後者的比率是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.

“我們得到了確定的結果，我覺得這很重要，”食物過敏研究和教育組織(Food Allergy Research and Education)的負責人小詹姆斯·R·貝克博士(Dr. James R. Baker Jr.)說。該組織是資助這項研究的一個倡議組織。

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.

其他需要說明的情況是：父母們知道自己在哪個組。這項研究是在倫敦的單個地方進行的，其中75%是白人兒童。不過，研究者說，這項研究中的其他少量族羣的結果也是一樣的。

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，目前仍不明確的是，如果常規的花生餵養中斷，是否仍會發展成過敏症。爲了測試這一點，這項研究中的孩子們五歲後中止食用花生，繼續觀察了一年。

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.

還有一點不確定的是，同樣的策略是否適用於其他致敏食物或沒有花生過敏高風險的兒童。有些兒科醫生說，如果給有風險的孩子餵食花生製品是有益的，那麼沒理由不給不易過敏的兒童吃這些食物。

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.

改變做法可能並不容易。“我確實認爲父母們最怕給孩子吃花生，”西北大學的古普塔說。八年前，她不讓自己的幼女吃花生，因爲女兒已出現溼疹，且對雞蛋過敏。她女兒後來患上了花生過敏症。

In light of the new study, Dr. Gupta said, “I’m kind of slapping myself on the wrist.”

古普塔說，看到這項新研究，“我有點自責”。