Food May Be Too Clean For Our Own Good
食品太乾淨 可能反倒有害
By Kate Murphy

With the recent recalls of millions of liters of ice cream as well as several tons of hummus, pine nuts, frozen vegetables and various meat products, you might think the American food supply is an unholy mess. It’s not. It’s arguably the safest in the world.
最近廠商回收數百萬公升的冰淇淋，數噸的鷹嘴豆泥、松堅果、冷凍蔬菜和多項肉品，有人可能因此認為，美國的食品供應亂七八糟。其實不然。它的安全性堪稱全球第一。

Yet despite continually improving processing methods and quality controls, the number of cases of food-borne illness has remained high since the 1990s, with the incidence of people getting sick from some pathogens increasing.
然而，儘管在加工處理和品質管制方面不停地改善，自1990年代以來，透過食物感染的疾病病例依然始終居高不下，因為某些病原體而病倒的病例甚至有增無減。

Some experts wonder if we’ve reached a point of diminishing returns in food safety – whether our food could perhaps be too clean.
部分專家不禁懷疑，美國在食安方面已經來到了收益遞減的那個點上，也就是說，美國的食物或許已經乾淨得過了頭。

Industrial food sanitation practices – along with home cooks’ antibacterial veggie washes, chlorine bleach kitchen cleaners and sterilization cycle dishwashers – kill off so-called good bacteria naturally found in foods that bolster our health. Moreover, eliminating bad or pathogenic bacteria means we may not be exposed to the small doses that could inoculate us against intestinal crises.
食品工業衛生管理（消毒殺菌），以及在家料理使用的抗菌蔬果清洗液，含氯漂白劑的廚房清潔用品，消毒循環洗碗機，都會殺死天然食物中可增進人體健康的所謂好菌。而且，完全消滅壞菌和致病細菌，意味我們可能無法暴露於少量的細菌，以致無法保護我們的腸道免於出現危機。

“No one is saying you need to eat a peck of dirt before you die to be healthy,” said Jeffrey T. LeJeune, a professor and head of the food animal research program at Ohio State University in Wooster. “But there is a line somewhere when it comes to cleanliness. We just don’t know where it is.”
伍斯特「俄亥俄州立大學」教授兼食品動物研究計畫負責人傑佛瑞．T．勒瓊說：「沒有人說，人死前，必須吃進一堆汙垢，身體才會健康。乾淨這件事，其中有條界線，只不過我們不知道它在那裡。」

The theory that there might be such a thing as “too clean” food stems from the hygiene hypothesis, which has been gaining traction over the last decade. It holds that our modern germaphobic ways may be making us sick by harming our microbiome, which is the system made up of all the microbes – bacteria, viruses, fungi, mites – that live in and on human bodies.
食物可能有「過度乾淨」之嫌的理論，源自這十年來備受注目的「衛生假說」。它的立論是，現代人的潔癖可能破壞我們的微生物群系，使我們生病，微生物群系是所有存活於人體內外的微生物，包括細菌、病毒、真菌、蟲組合而成的系統。

A result of a diminished microbiome is an immune system that gets bored, spoiling for a fight and apt to react to harmless substances and even attack the body’s own tissues. This could explain the increasing incidence of allergies and autoimmune disorders such as asthma, rheumatoid arthritis and inflammatory bowel disease.
微生物群系減弱的結果，是免疫系統會覺得無聊，一心想戰鬥，因此易於對無害的物質產生反應，甚至攻擊自己身體的組織。這可解釋過敏和自體免疫性失常疾病如氣喘、類風濕關節炎、發炎性腸道疾病發病率越來越高的原因。

There is also the suggestion that a diminished microbiome disrupts hormones that regulate hunger, which can cause obesity.
另一種說法是，微生物群系減少會擾亂調節飢餓的荷爾蒙，導致肥胖。

When it comes to food-borne illness, the idea is that fewer good bacteria in your gut means there is less competition to prevent colonization of the bad microbes, leading to more frequent and severe bouts of illness.
至於食物感染性疾病，它的說法是，腸道內的好菌一旦減少，意謂防止壞菌入侵的競爭力降低，疾病發作將更為頻繁與嚴重。

Moreover, an underutilized immune system may lose its ability to discriminate between friend and foe, so it may marshal its defenses inappropriately (against gluten, for example) or not at all.
此外，未能充分利用的免疫系統，可能喪失區分敵友的能力，因此以不當方式重新配置它的防禦能力（例如對付麩質），或者文風不動。

Animal experiments have lent some credence to the theory. Researchers at Texas Tech University in Lubbock have found that guinea pigs fed less virulent strains of listeria are less likely to get sick or die when later fed a more pathogenic strain. And anyone who has visited a country with less than rigorous sanitation knows the locals don’t get sick from foods that can cause tourists days of toilet-bound torment.
動物實驗提高了這項理論的可信度。拉巴克「德州理工大學」的研究員發現，實驗天竺鼠先餵以毒性較弱的李斯特菌株，其後再餵以致病性較強的菌株時，較不易生病或死亡。此外，曾經造訪過衛生條件較差國家的人都知道，當地人吃了沒事的食物，可能讓觀光客飽受接連數天老跑廁所之苦。

“We have these tantalizing bits of evidence that to my mind provide pretty good support for the hygiene hypothesis, in terms of food-borne illness,” said Guy Loneragan, a professor of food safety and public health at Texas Tech.
德州理工大學食品安全與公共衛生教授蓋伊．朗雷根說：「我們有這些誘人的證據，對我而言，就食物感染性疾病來說，它們為衛生假說提供了很好的佐證。」

This is not to say we’d be better off if chicken producers eased up on the salmonella inspections, we ate recalled ice cream sandwiches and didn’t rinse our produce. But it raises questions about whether it might be advisable to eradicate microbes more selectively.
這並不意謂，若是雞農放鬆沙門氏菌檢驗，人們照吃回收的冰淇淋三明治，或不沖洗農產品，對我們會更好。但它提出了一個問題：或許更有選擇性的消滅微生物，才是正道。

原文參照：
http://www.nytimes.com/2015/05/10/sunday-review/invite-some-germs-to-dinner.html

2015-05-26聯合報/G5版/UNITED DAILY NEWS 王麗娟譯 原文參見紐時週報十版下