手機(jī)版
As I was sitting in the office one day, a colleague at a desk 3ft away looked up with a curious expression.
She glanced around searchingly until her gaze settled on me.
‘My dear,’ she said in her customary grand manner, ‘are you wearing perfume?’
I nodded, replying: ‘Do you like it?’ She smiled at me graciously.
‘It’s simply frightful,’ she announced at a volume akin to the average loudhailer, adding: ‘So cheap!’
Choosing perfume by guesswork is just one of the pitfalls of my life as an anosmic — a person with no sense of smell.
From the fragrance of roses to the smell of burning, I’m oblivious to them all.
I am among the one in 5,000 people born anosmic — others lose their sense of smell through head trauma (Tottenham manager Harry Redknapp lost his after a car crash) or as the result of a simple flu or cold virus.
It’s thought that 200,000 Britons have anosmia — famous sufferers have included William Wordsworth, INXS singer Michael Hutchence and actor Bill Pullman.
Yet the vast majority of people able to smell have not only never heard of anosmia, but its existence has not occurred to them. The unfailing response I receive is a blank stare, before they insist: ‘But you must be able to smell baking bread or sour milk.’
If I were blind, no one would say: ‘But you must be able to see this very large mountain or that very bright light.’ So, to repeat . . . I. Can’t. Smell. At all.
‘The estimated number of anosmics is likely to be hugely inaccurate because most just cope and never mention it,’ says smell specialist Professor Tim Jacob, of Cardiff University’s School of Biosciences.
‘Lots of congenital anosmics say they don’t even realise they have no sense of smell until their teens.
'As young children they can’t understand the concept of smell but do not wish to appear different to their peers, so they learn the appropriate reactions to good or bad smells from other people’s cues.’
He adds: ‘To most people anosmia is unimportant. The condition hasn’t even entered the consciousness of the medical profession. It has no NHS budget and GPs have no idea about it.’
Even ear, nose and throat specialists aren’t trained in anosmia, according to Professor Jacob, despite the fact that dozens of viruses of the upper respiratory tract can cause it.
He says: ‘I get letters constantly from people who feel very let down by the medical profession and who are desperate for answers.’
Famous sufferers of anosmia include actor Bill Pullman (left) and the late INXS singer Michael Hutchence (right)
The fact is those answers are few. Put simply, our ability to smell is generated by receptor nerve cells at the top of the nose — these send signals via the olfactory nerves to the olfactory cortex in the brain.
In anosmia, the olfactory nerves are damaged or die (people born with anosmia may lack these nerves completely — this form of the condition is genetic, although it can skip generations).
‘In anosmia caused by head trauma or virus, the olfactory nerve is damaged,’ explains Professor Jacob.
‘Most human nerves do not regenerate. If they get broken or cut, that’s that, although research is progressing.’
In other words, anosmics are largely stuck with it. Those with acquired anosmia may experience the temporary return of smell for reasons not yet understood. They may also experience phantosmia — the detection of an odour where none is present.
‘It works the same way as phantom pains in a lost limb,’ explains Professor Jacob.
‘If you no longer receive sensory input from the nose, then the brain regions dealing with smell receive random information.Then what’s left of the nerve pathway can trigger the region of the brain dealing with smell, triggering an apparent smell even though there is none.’
This is the case with investment banker Ben Colegrave, 30, who became anosmic after a life-threatening head injury in a road accident seven years ago.
‘The other day my girlfriend and I got into a taxi which to me smelled strongly of curry,’ he recalls.
‘But my girlfriend said there was no smell of curry. That happens every now and again.
‘I miss the memory triggers of smells, and being able to associate a smell with an individual person. Above all I miss the excitement of breathing in an unfamiliar aroma as you get off the plane in a new country.’
Ben is sanguine about his anosmia (‘I could have died, so it doesn’t seem very important’), but loss of smell can be devastating.
According to Professor Jacob, 17 per cent of people who become anosmic subsequently suffer clinical depression, often because their sensory experience of food is so depleted.
Anosmics retain a normal sense of taste, distinguishing between sweet, sour, salt, bitter and umami (savoury) like everyone else.
However, we can’t distinguish between flavours, as this is almost entirely down to smell. Molly Birnbaum was 20 and a would-be chef when a head injury in a road accident left her anosmic.
‘Food had been my consuming passion,’ says Birnbaum, now a writer, in her just published book Season To Taste.
‘Then I dreaded eating. The scent of garlic and roasting meat fell on lifeless olfactory nerves. A bite of steak may as well have been a chunk of warm cardboard.
‘I examined every piece of food. That milk: fresh or sour? That spinach: new or old? I had only the visual to guide me.’
Professor Jacob says anosmics use other signals, such as texture, acidity and hydration, to compensate for absence of flavour. Ben Cohen, of ice cream duo Ben & Jerry’s, is a congenital anosmic and insisted on large chunks in their products to improve his perception of flavour.
‘Of course, smell also acts as a hazard warning,’ says Professor Jacob, ‘not only against lethal dangers such as gas or fire, but against food which is going off.’ As someone who’s accidentally eaten rotten fish, I can confirm it is unbelievably disgusting.
Researchers are garnering scattered facts about anosmia. Diminished ability to smell can be an early sign of Parkinson’s.
‘Some of the main brain degeneration seen in Parkinson’s is seen first in the olfactory bulb (where the olfactory nerves meet),’ says Professor Jacob.
‘That said, many men lose around half their sense of smell by the age of 80 simply as a function of age. Women tend to retain it.’
Anosmia is also linked to loss of libido, though again, it’s not clear why.
As for us congenitals, we rarely think about our anosmia, as it has always been our normality.
But I do quite often wonder if either I or my house smell terrible, and people are simply too polite to tell me. And I’ve learned it pays to take a friend along when buying perfume.
參考譯文：
有一天我正在辦公室里坐著，一個(gè)離我有三英尺遠(yuǎn)的同事突然一副好奇的表情，好像正在附近尋找著什么，而最后她把目光鎖定在了我身上。
“我的天哪，”她用她慣用的嚴(yán)肅的語(yǔ)氣問我，“你噴香水了？”
我點(diǎn)了點(diǎn)頭，說道：“你喜歡這個(gè)味道么？”而她則是回應(yīng)了我一個(gè)溫柔的微笑。
“真可怕，這香水聞起來…”，她用和大喇叭差不多的音量接著說道，“好廉價(jià)！”
作為一個(gè)嗅覺缺失者——對(duì)氣味沒有感知能力的人，只憑借想象來選擇香水只是嗅覺喪失癥給我的生活帶來的諸多不便之一。
從玫瑰花的香味到燃燒的氣味，我通通感知不到。
大約每五千個(gè)人中會(huì)有一個(gè)人患有先天性的嗅覺缺失癥，我就是其中一員——還有一些人因?yàn)轭^部創(chuàng)傷（熱刺隊(duì)的經(jīng)理哈里•雷德克納普在一場(chǎng)車禍之后喪失嗅覺）或被流感或傷寒病毒感染，后天失去了嗅覺。
據(jù)說有嗅覺喪失正的英國(guó)人有200，000個(gè)之多——其中比較有名的有威廉姆•華滋華斯，伊克斯樂隊(duì)的主唱邁克爾•哈琛斯和演員比爾•普爾曼。
然而，擁有正常嗅覺的大多數(shù)人不僅僅是從未聽說過嗅覺缺失癥，而是對(duì)它的存在完全沒有任何概念。人們?cè)诼犝f之后給我的答復(fù)永遠(yuǎn)是面無表情的凝視，之后他們還會(huì)堅(jiān)持說：“但是你肯定還是能聞見烤面包味或酸牛奶味是吧。”
但如果我是盲人，肯定不會(huì)有人對(duì)我說：“但是你肯定還是能看見那座大山或者很亮的光是吧。”因此，我總在重復(fù)一句話……我，啥，都，聞，不，見。
“患有嗅覺缺失癥的估計(jì)人數(shù)很可能存在嚴(yán)重誤差，因?yàn)楹芏嗳硕茧[瞞了這件事，”卡迪夫大學(xué)生物學(xué)院的嗅覺專家，蒂姆•雅各布教授說。
“許多先天性嗅覺喪失正患者說，他們?cè)谑畾q以前甚至都沒意識(shí)到自己沒有嗅覺。”
“小孩雖然沒有完全理解嗅覺的概念，但因?yàn)樗麄儾幌牒蛣e的孩子表現(xiàn)的不同，所以他們就通過模仿別人，同他人一樣也對(duì)好的或不好的氣味做出適當(dāng)?shù)姆磻?yīng)。”
他還說：“對(duì)大多數(shù)人來說，嗅覺缺失癥根本不重要。而這種情況也還沒有進(jìn)入醫(yī)療從業(yè)者的自覺當(dāng)中。這類患者不享受英國(guó)國(guó)民健康保險(xiǎn)制度（NHS）中規(guī)定的補(bǔ)償，普通開業(yè)醫(yī)生對(duì)此也毫無概念。”
據(jù)雅各布教授說，許多耳鼻喉科專家也并未對(duì)嗅覺喪失癥有過專門訓(xùn)練，盡管有好幾十種上呼吸道病毒都有可能引發(fā)這種病。
他說：“我不斷接到患者的信件，他們或是因?yàn)獒t(yī)療人員而對(duì)此感到失望，或是極其渴望得到關(guān)于這病的解決辦法。”
比較有名的嗅覺喪失癥患者有演員比爾•普爾曼，和伊克斯樂隊(duì)的主唱邁克爾•哈琛斯。
但事實(shí)是，這病確實(shí)沒有治療辦法。簡(jiǎn)單的說，我們能夠聞到氣味是因?yàn)楸乔徽衬ど系纳窠?jīng)細(xì)胞能接受氣味的信號(hào)——然后這種信號(hào)通過嗅覺神經(jīng)傳導(dǎo)到大腦中的嗅皮質(zhì)。
患有嗅覺缺失癥的人，其嗅覺神經(jīng)是損壞的或死亡的（天生嗅覺缺失的人可能是生來就完全沒有嗅覺神經(jīng)——這種情況就是可遺傳的，盡管發(fā)生隔代遺傳也會(huì)隨基因傳遞下去）。
“而因?yàn)轭^部損傷或病毒引起的嗅覺缺失癥，患者的嗅覺神經(jīng)是被損壞了。”雅各布教授解釋道。
“一般人類的大多數(shù)神經(jīng)都不會(huì)再生了。如果他們被損壞或切斷了，那就無法改變了，盡管這方面的研究也在進(jìn)行。”
換句話說，嗅覺缺失癥在很大程度上說是無法擺脫的。那些后天嗅覺確實(shí)的人們有可能會(huì)因?yàn)槟承┰颢@得暫時(shí)性的嗅覺恢復(fù)。他們還可能會(huì)出現(xiàn)幻嗅——感知到根本不存在的氣味。
“這個(gè)原理和患肢痛感差不多，”雅各布教授解釋道。
“如果你再也接收不到來自于鼻子的嗅覺信號(hào)，大腦的嗅覺區(qū)域就會(huì)接收到一些隨機(jī)信息。然后其他的神經(jīng)傳導(dǎo)途徑就會(huì)觸發(fā)大腦的嗅覺區(qū)域，產(chǎn)生一些不存在的嗅覺感受。”
這就是30歲的投資銀行家Ben Colegrave的案例，他在七年前的一場(chǎng)危及生命的交通事故中損傷了頭部，之后便患上了嗅覺缺失癥。
“前幾天我和我女朋友上了一輛出租車，我聞到了一股很強(qiáng)烈的咖喱味，”他回憶道。
“但是我的女朋友說根本沒聞到咖喱味。這種情況時(shí)常發(fā)生。”
“我懷念還有嗅覺的那段時(shí)光，那時(shí)候我可以吧聞到的氣味與一個(gè)人聯(lián)想起來。總之，我現(xiàn)在已無法體驗(yàn)?zāi)欠N呼吸到一種不熟悉的氣味的新鮮感，就像剛從飛機(jī)上下來踏上一片從未到過的土地時(shí)的感覺一樣。”
Ben能很樂觀的看待他的嗅覺缺失癥（“在那次事故中我差點(diǎn)沒命，而這點(diǎn)小病就顯得不那么重要了”），但是從此以后聞不到味道對(duì)他來講也是個(gè)重大的打擊。
雅各布教授表示，有17%的人在嗅覺缺失癥之后患上了憂郁癥，經(jīng)常是因?yàn)樗麄儗?duì)于食物的感覺變得越發(fā)貧乏了。嗅覺缺失癥的患者還能保持與正常人一樣的味覺，能夠分辨甜味，酸味，咸味，苦味和鮮味。
然而，他們并不能區(qū)分不同味道，因?yàn)槟侵饕Q于氣味。莫麗•伯恩鮑姆在20歲即將成為廚師的時(shí)候經(jīng)歷了一場(chǎng)車禍，頭部損傷導(dǎo)致她喪失了味覺。
“食物曾經(jīng)是我消費(fèi)的動(dòng)力，”成為了作家的伯恩鮑姆在她剛出版的書《品味四季》中如是寫道。
“但是之后，我對(duì)飲食產(chǎn)生了恐懼。大蒜和烤肉散發(fā)出來的氣味落到了我死亡的味覺神經(jīng)上。咬上一口牛排的感覺就好像是咬上了一塊溫?zé)岬暮窦埌濉?rdquo;
“我會(huì)去反復(fù)檢查每一塊食物。這些牛奶是新鮮的還是壞掉的？那些菠菜是新的還是老的？現(xiàn)在我只能靠視覺來引導(dǎo)我了。”
雅各布教授說，喪失嗅覺的患者們還會(huì)用其他特征來彌補(bǔ)其嗅覺的不足，比如質(zhì)地，酸度和水分含量等。班杰瑞冰激凌品牌的創(chuàng)始人之一本•科恩就是一個(gè)先天嗅覺缺失者，他堅(jiān)持把產(chǎn)品做成量大型，來提升人們對(duì)冰激凌口味的感知。
“當(dāng)然，嗅覺也會(huì)負(fù)擔(dān)起危險(xiǎn)警示的作用，”雅各布教授說，“它不僅會(huì)在感受到對(duì)汽油或燃燒的有毒氣味發(fā)出警告，還會(huì)在感知到食物變質(zhì)后發(fā)出警告。”因?yàn)槿绻腥瞬恍⌒某粤烁癄�的魚，我能肯定那味道會(huì)非常非常惡心。
研究者不斷的獲得了一些關(guān)于嗅覺缺失癥各個(gè)方面的信息。比如，嗅覺能力的減弱可能是帕金森氏癥的早期預(yù)兆。
“一些在帕金森氏癥中顯示出的大腦退化最先發(fā)生在嗅球（嗅覺神經(jīng)聚集的地方），”雅各布教授說。
“還有一說，許多男性在80歲的時(shí)候僅僅因?yàn)樗ダ隙鴨适Я藢⒔话氲男嵊X能力，而女性則不然。”
嗅覺缺失癥貌似還與性欲的降低有關(guān)，盡管原因還不是很明確。
但是對(duì)我們這些先天性嗅覺缺失的人來說，我們倒很少想關(guān)于這病的事兒，因?yàn)檫@已經(jīng)成為一種常態(tài)了。
但是我經(jīng)常會(huì)想，如果我或者我的家里聞起來特別糟糕，而人們還又沒好意思告訴我的話會(huì)是怎樣呢。雖然我現(xiàn)在已經(jīng)會(huì)在買香水的時(shí)候拽上一個(gè)朋友幫我挑了。
相關(guān)閱讀：人類嗅覺識(shí)別機(jī)制探密
