A few weeks ago, the Food Standards Agency （FSA） in the UK issued a report evaluating nutrient levels in organic versus non-organic foods like fruits, vegetables, meats, eggs, and dairy products. A team at the London School of Hygiene & Tropical Medicine systematically reviewed 162 studies from more than 50 years of research and 3,558 comparisons of nutritional value in food. It is a complete, rigorous piece of research. And they found that, in terms of nutritional content, the differences between organic and non-organic foods are negligible.

    As the report states, "…organically and conventionally produced crops and livestock products are broadly comparable in their nutrient content." They did in fact find some nutritional differences between organic and non-organic foods （non-organic crops contain more nitrogen, while organic crops have higher levels of magnesium and zinc, for instance）, but concluded that it is "unlikely that these differences in nutrient content are relevant to consumer health."

    So here we have a nicely delimited study of available research with rigorous standards and a fairly worded conclusion, all publicly available to download and read on the FSA website. The reaction, not surprisingly, was spectacular. The British tabloids alternately hooted with delight at the comeuppance of posh bourgeois shopping habits or derisively attacked the study for insulting the people's common sense. But it was the reaction of the Soil Association, the leading British organic certification organization, which highlighted just how difficult it can be for good science to be understood.

    The Soil Association's response, published in papers across the land, entirely disregarded the intent of the study and instead argued that organic food is better for the environment and contains less pesticides than non-organic food. But in the very first paragraph of the report, the team states that they aren't looking at the impact on the environment of organic agriculture or the effect of pesticide use, both of which the FSA has extensively examined in other research. They are specifically looking at nutritional comparison. The Soil Association further argued that the FSA report had ignored studies that showed any benefit of organic food. It was the kind of petulant response worthy of a misinformed PR flack with a nation to persuade. As Ben Goldacre incisively dissected on his popular blog,Bad Science, the Soil Association's response was logically flawed and entirely beside the point.

    The FSA study is good science and by attacking, rather than endorsing it, the organic lobby in the UK has been plainly unscientific. It's hardly the right stance for an organization that carries such widespread support from the well-educated, critical-thinking middle classes who choose to eat organic food. Any of the many other reasons to go organic-whether it is to avoid pesticides, to encourage better livestock practices, or to simply eat better tasting food-are sufficient to continue supporting the efforts of organic farmers. By misrepresenting the science and its intent, the Soil Association has damaged its credibility and objectivity, the very attributes that its organic label-a stamp of approval-is intended to convey.

    In the United States this week, the USDA announced that it would be auditing the National Organic Program, which administers production, handling, and labeling standards for all US organic food. The intent of the audit is to, among other things, "build the organic community's trust in the program." As Marion Nestle, author of What to Eat points out on her blog, Food Politics, the US public "deeply distrusts the integrity of the organic standards, the honesty of the inspection process, and the claims made for the benefits of organic foods." If the example in the UK is anything to go by, the US consumer has every reason to be skeptical.

    幾周以前，英國的食品標準局（FSA）發表了一份報告，報告評估了有機生產的水果、蔬菜、肉類、雞蛋和奶制品等與非有機生產的同類食品營養水平的差異。倫敦衛生及熱帶醫學學院的一個研究團隊系統回顧了過去50多年中針對3558種食品營養價值比較的162項研究成果。這是一項完整而嚴謹的研究。通過研究他們發現，在營養成分上，有機和非有機食品間的差距可以忽略不計。

    研究報告指出："有機生產與常規生產的農作物及牲畜產品在營養成分上基本沒有差別。"研究小組也確實發現了有機食品與非有機食品在營養成分上的一些細微區別（例如非有機生產的農作物氮含量更高，而有機生產的農作物鎂、鋅含量則略高）,不過報告的結論同時承認"這些營養成分的差異不大可能對消費者的健康產生影響。"

    因此，通過使用嚴格的標準對現有研究成果進行評估，報告得出了一個相當明確的結論，其全文可在FSA的網站上下載閱讀。這一報告毫無懸念地引起了強烈的反響。英國報章的反應十分兩極化：一些報章聲稱這一研究結果是對資產階級奢侈購物習慣的極大諷刺，另一些則攻擊說這一研究結果侮辱大眾的常識。然而英國土壤協會這一在英國有機食品認證中居于領導地位的機構所做出的反應則實在地表明一項優秀的科研成果要被人所理解是多么地困難。

    英國土壤協會發表在公開刊物上的回應完全無視這一研究的初衷，并辯稱有機食品中農藥的水平更低，更有利于環境保護。而研究小組在FSA報告的第一段就特別聲明本項研究并不關注有機農業或農藥對環境的影響。本次研究只針對營養成分的對比。其余兩部分的內容FSA都在另外的專門研究中進行了深入的探討。英國土壤協會進一步辯稱FSA的報告完全忽略了那些表明有機食品具有優越性的研究成果。這一反應顯得情緒化并且在公關上也不夠成功。本。高德克里在他那廣受歡迎的博客"科學的負面"中一針見血的指出，英國土壤協會的反應邏輯混亂并且離題萬里。

    FSA的研究十分出色，有機食品業者大肆攻擊這一研究結果而不是贊同其正確性的做法顯然不夠科學。對于英國土壤協會這樣一個受到喜好有機食品的中產階級精英廣泛支持的組織來說，這絕對不是正確的立場。對于繼續支持有機農業農場主來說，選擇有機食品的其他那些理由已經足夠。例如為了避免農藥殘留、改善畜牧業條件抑或單純地地為了品嘗更好的食物。通過扭曲科學研究及其初衷，英國土壤協會的可信性及客觀性都受到了嚴重的損害。

    美國農業部近期也宣布將審議其監管全美有機食品生產、處理及貼標標準的"國家有機農業計劃".審議計劃的目的是為了"建立有機農業界的信譽","吃什么？"一書的作者瑪瑞安。耐斯特里在她的博客"食品政策"中指出，美國公眾"對有機食品標準、檢驗過程的誠信度以及對有機食品優點的宣傳充滿了不信任感。"如果說英國發生的事情具有借鑒意義的話，那么美國的消費者也完全有充足的理由對有機食品業表示懷疑。