and now I'm an epidemiologist.

所以現在我也是個流行病學家

And nobody really knows what epidemiology is.

沒有人真正知道流行病學是什麼

Epidemiology is the science of how we know in the real world

流行病學是一種科學，讓我們知道在生活中

if something is good for you or bad for you.

什麼東西對你好，或對你不好

And it's best understood through example

而有例可循最是簡單明瞭

as the science of those crazy, wacky newspaper headlines.

好比誇張、奇怪的新聞標題就是一例

And these are just some of the examples.

這裡有些例子

These are from the Daily Mail. Every country in the world has a newspaper like this.

它們來自《每日郵報》，全世界各國都有類似的報紙

It has this bizarre, ongoing philosophical project

這類報紙一直都有個古怪、看似有理的企畫

of dividing all the inanimate objects in the world

就是將世界上所有不會動的物件

into the ones that either cause or prevent cancer.

都分別歸類成致癌物或防癌物。

So here are some of the things they said cause cancer recently:

這些是一部分最近據說會致癌的玩意兒

divorce, Wi-Fi, toiletries and coffee.

離婚、無線網路、衛生用品和咖啡

Here are some of the things they say prevents cancer:

而這些則是據說能防癌的東西

crusts, red pepper, licorice and coffee.

麵包皮、紅椒、甘草和咖啡

So already you can see there are contradictions.

我想你看到了矛盾的地方

Coffee both causes and prevents cancer.

咖啡同時致癌也防癌

And as you start to read on, you can see

當你開始讀下去，你會發現

that maybe there's some kind of political valence behind some of this.

這些報導說不定別有用心。

So for women, housework prevents breast cancer,

拿女性來說，做家事能預防乳癌

but for men, shopping could make you impotent.

但對男性而言，購物會使他們性無能

So we know that we need to start

所以，我們要開始

unpicking the science behind this.

揭露這一切背後的科學真相

And what I hope to show

我想要做的

is that unpicking dodgy claims,

是揭穿那些騙人的說法

unpicking the evidence behind dodgy claims,

以及那些假象背後的證據，

isn't a kind of nasty carping activity;

這並非卑鄙、催毛求疵的事

it's socially useful,

這對社會有用，

but it's also an extremely valuable

同時，也是個極具價值的

explanatory tool.

解說工具。

Because real science is all about

因為真正的科學

critically appraising the evidence for somebody else's position.

是批判地評斷他人提出的證據

That's what happens in academic journals.

這就是在學術期刊，

That's what happens at academic conferences.

以及學術研討論上，上演的戲碼。

The Q&A session after a post-op presents data

有時在發言完後的問答時間

is often a blood bath.

就像場血戰。

And nobody minds that. We actively welcome it.

但沒人在乎，我們還熱烈歡迎。

It's like a consenting intellectual S&M activity.

就像是雙方同意，來場學術上的激烈性愛一樣。

So what I'm going to show you

所以，接下來要讓各位看的

is all of the main things,

是我的研究領域

all of the main features of my discipline --

也就是流行病學的主要特色－

evidence-based medicine.

循證醫學。

And I will talk you through all of these

我會一步步的講解，

and demonstrate how they work,

說明他們是如何運作的，

exclusively using examples of people getting stuff wrong.

但不會拿出錯的事情做為例子。

So we'll start with the absolute weakest form of evidence known to man,

一開始，我們先談最不堪一擊的證據來源

and that is authority.

就是權威。

In science, we don't care how many letters you have after your name.

在科學界，我們不在乎你名字後面有多少頭銜，

In science, we want to know what your reasons are for believing something.

我們想知道，你發表某樣事物的背後有什麼理由。

How do you know that something is good for us

你怎麼知道那對我們是好，

or bad for us?

還是不好？

But we're also unimpressed by authority,

但，因為權威容易偽造，

because it's so easy to contrive.

所以我們對權威並不有什麼感覺。

This is somebody called Dr. Gillian McKeith Ph.D,

這是麥基絲醫生博士

or, to give her full medical title, Gillian McKeith.

或者，給她一個完整的醫學頭銜，吉輪 ●麥基絲。

(Laughter)

(笑聲)

Again, every country has somebody like this.

每個國家都有像這個的一個人。

She is our TV diet guru.

她是電視上的健康飲食大師，

She has massive five series of prime-time television,

她有多達五個黃金時段的系列節目

giving out very lavish and exotic health advice.

分享又豐富，又充滿異國風情的保健建議

She, it turns out, has a non-accredited correspondence course Ph.D.

結果，她的學歷只是在美國某一大學的

from somewhere in America.

非公認的函授課程博士。

She also boasts that she's a certified professional member

她也自豪地說她是美國營養顧問協會

of the American Association of Nutritional Consultants,

的認證專業會員

which sounds very glamorous and exciting.

聽起來是多麼吸引人又讓人興奮

You get a certificate and everything.

你有張結業證書，就什麼都有了

This one belongs to my dead cat Hetti. She was a horrible cat.

這是我的貓，海地，她已經過世了，一隻很不乖的貓

You just go to the website, fill out the form,

你只要上網，填表格，

give them $60, and it arrives in the post.

交六十塊給他們，然後證書就郵寄給你

Now that's not the only reason that we think this person is an idiot.

但，這不是我們覺得這傢伙是笨蛋的唯一理由

She also goes and says things like,

她也會說些話像是

you should eat lots of dark green leaves,

你該吃很多的深綠色蔬菜，

because they contain lots of chlorophyll, and that will really oxygenate your blood.

因為深綠色蔬菜有大量葉綠素，可讓血液充滿氧氣

And anybody who's done school biology remembers

但，任何在學校做過生物實驗的人都記得

that chlorophyll and chloroplasts

葉綠素及葉綠粒

only make oxygen in sunlight,

只透過光合作用來製造氧氣

and it's quite dark in your bowels after you've eaten spinach.

而當你把菠菜吃掉時，身體裡其實是黑暗的

Next, we need proper science, proper evidence.

接著，我們需要正確的科學、有理的證據來證實

So, "Red wine can help prevent breast cancer."

「紅酒可預防乳癌。」

This is a headline from the Daily Telegraph in the U.K.

這是英國的《每日電訊》的頭條新聞

"A glass of red wine a day could help prevent breast cancer."

「一天一杯紅酒能幫助預防乳癌。」

So you go and find this paper, and what you find

接著你去找這則新聞，你會發現

is it is a real piece of science.

這確實有科學佐證

It is a description of the changes in one enzyme

這是描述某實驗室的工作臺上的培養皿，

when you drip a chemical extracted from some red grape skin

把紅葡萄皮上所萃取的化學物質，

onto some cancer cells

滴到一些癌細胞上，

in a dish on a bench in a laboratory somewhere.

酵素會產生變化

And that's a really useful thing to describe

就科學報告而言，

in a scientific paper,

這樣的實驗描述很有用，

but on the question of your own personal risk

但，一問到喝紅酒

of getting breast cancer if you drink red wine,

和得到乳癌的風險為何，

it tells you absolutely bugger all.

這樣的實驗描述什麼屁都沒告訴你。

Actually, it turns out that your risk of breast cancer

事實上，你得到乳癌的風險

actually increases slightly

會隨著你喝的含酒精飲料

with every amount of alcohol that you drink.

一點一點的增加

So what we want is studies in real human people.

因此，我們要看的，是拿真人做的研究

And here's another example.

這是另一個例子

This is from Britain's leading diet and nutritionist in the Daily Mirror,

來自英國的《每日鏡報》，一位頗具影響力的飲食營養學家

which is our second biggest selling newspaper.

《每日鏡報》是英國銷售量第二的報紙

"An Australian study in 2001

「2001年，澳洲當地的實驗發現

found that olive oil in combination with fruits, vegetables and pulses

若把橄欖油與水果、蔬菜，或豆類植物搭配食用，

offers measurable protection against skin wrinklings."

將對皮膚防皺有相當顯著效果。」

And then they give you advice:

然後，他們就給妳這樣的建議：

"If you eat olive oil and vegetables, you'll have fewer skin wrinkles."

「如果把橄欖油及蔬菜搭配著吃，你的皺紋會比較少。」

And they very helpfully tell you how to go and find the paper.

他們也很熱心地告訴你文獻出處

So you go and find the paper, and what you find is an observational study.

而在你看完報告後，你就會知道這是份觀測研究

Obviously nobody has been able

很顯然地，沒人有辦法

to go back to 1930,

回到1930年

get all the people born in one maternity unit,

把同個產科所有出生的小孩找來

and half of them eat lots of fruit and veg and olive oil,

其中一半給他們吃水果、蔬菜和橄欖油

and then half of them eat McDonald's,

另一半給他們吃麥當勞

and then we see how many wrinkles you've got later.

之後，看他們的皺紋誰多誰少

You have to take a snapshot of how people are now.

你得拍照記錄人們的樣子

And what you find is, of course,

當然，你會發現到

people who eat veg and olive oil have fewer skin wrinkles.

吃蔬菜和橄欖油的人，確實皺紋較少

But that's because people who eat fruit and veg and olive oil,

但，這是因為那些吃水果、蔬菜，橄欖油的人是怪胎

they're freaks, they're not normal, they're like you;

他們不正常，就像你們一樣

they come to events like this.

他們會出席TED這樣的活動

They are posh, they're wealthy, they're less likely to have outdoor jobs,

他們受歡迎、有錢、也不太可能做室外工作

they're less likely to do manual labor,

也不太從事勞力的工作

they have better social support, they're less likely to smoke --

他們在社會上獲得較多的支持，他們不太抽菸－

so for a whole host of fascinating, interlocking

因此，這麼多關於社會、政治，文化等等原因，

social, political and cultural reasons,

這些原因這麼棒，又如此環環相扣

they are less likely to have skin wrinkles.

而這些人，也就不太可能有皺紋

That doesn't mean that it's the vegetables or the olive oil.

這並不意味著蔬菜還是橄欖油的功勞

(Laughter)

(笑聲)

So ideally what you want to do is a trial.

所以，做實驗往往是最理想的選擇

And everybody thinks they're very familiar with the idea of a trial.

大家都認為，他們對於實驗都得很熟

Trials are very old. The first trial was in the Bible -- Daniel 1:12.

實驗是個老話題。第一個是出現在聖經－但以理書，第一章十二節

It's very straightforward -- you take a bunch of people, you split them in half,

這試驗很簡單，你找一群人，把他們分兩組

you treat one group one way, you treat the other group the other way,

這兩組人，你都用不同的方法去對待他們

and a little while later, you follow them up

過了一下子之後

and see what happened to each of them.

你就看會他們會發生什麼事

So I'm going to tell you about one trial,

現在我要和你說的這個試驗

which is probably the most well-reported trial

在過去十年的英國新聞媒體報導中

in the U.K. news media over the past decade.

可以算是名聲相當不錯的試驗

And this is the trial of fish oil pills.

這是個魚肝油的試驗

And the claim was fish oil pills improve school performance and behavior

魚肝油宣稱，可以改善大部分小孩的學業表現

in mainstream children.

及學校行為

And they said, "We've done a trial.

他們說：「我們做了個試驗

All the previous trials were positive, and we know this one's gonna be too."

而之前的試驗結果都是好的，我想我們的也會是好的。」

That should always ring alarm bells.

會這樣說，就是個警訊

Because if you already know the answer to your trial, you shouldn't be doing one.

當你已經知道實驗的結果，那還做它幹什麼

Either you've rigged it by design,

無論這試驗只是隨意起草

or you've got enough data so there's no need to randomize people anymore.

或是你已有充分的數據，而你已不需要隨機挑選更多的試驗者

So this is what they were going to do in their trial.

實驗就是這樣進行的

They were taking 3,000 children,

他們找了三千位孩童

they were going to give them all these huge fish oil pills,

並給孩童吃很多的魚肝油

six of them a day,

一天吃六顆

and then a year later, they were going to measure their school exam performance

一年後，他們來測量孩童的學業表現

and compare their school exam performance

並把得來的結果和

against what they predicted their exam performance would have been

這些孩童沒有吃魚肝油的預期結果

if they hadn't had the pills.

來兩相比較

Now can anybody spot a flaw in this design?

有人現在看出這實驗設計的缺失了嗎？

And no professors of clinical trial methodology

所有臨床試驗方法的教授

are allowed to answer this question.

都不準回答這問題

So there's no control; there's no control group.

這實驗沒有對照組

But that sounds really techie.

聽起來像電子迷才會做的事

That's a technical term.

那是一個專業術語

The kids got the pills, and then their performance improved.

孩童吃了魚肝油，他們的學業表現進步了

What else could it possibly be if it wasn't the pills?

除了魚肝油，還有什麼其它的原因嗎?

They got older. We all develop over time.

他們隨著時間長大了

And of course, also there's the placebo effect.

當然，還有安慰劑的影響

The placebo effect is one of the most fascinating things in the whole of medicine.

安慰劑的效果是所有藥品中，最令人神往的一個

It's not just about taking a pill, and your performance and your pain getting better.

不是吃藥而已，然後你的表現變好，疼痛舒緩如此而已

It's about our beliefs and expectations.

是我們的信念，以及期望

It's about the cultural meaning of a treatment.

這就是治療的文化定譯

And this has been demonstrated in a whole raft of fascinating studies

許多很好的研究也和安慰劑的效果

comparing one kind of placebo against another.

做了對照實驗

So we know, for example, that two sugar pills a day

舉例來說，一天吃兩顆糖的人

are a more effective treatment for getting rid of gastric ulcers

較不容易得到胃潰瘍

than one sugar pill.

和吃一顆糖的人相比

Two sugar pills a day beats one sugar pill a day.

一天吃兩顆糖比吃一顆糖更有用

And that's an outrageous and ridiculous finding, but it's true.

儘管這個發現讓人覺得奇怪又好笑，但這是事實

We know from three different studies on three different types of pain

從三種不同疼痛的研究當中，我們瞭解

that a saltwater injection is a more effective treatment for pain

注射生理食鹽水來治療疼痛，是個較有效的方法，

than taking a sugar pill, taking a dummy pill that has no medicine in it --

相較於吃糖果，安慰劑...等等沒有任何藥品成分的東西

not because the injection or the pills do anything physically to the body,

而這並非是注射或吃藥對生體產生了什麼影響

but because an injection feels like a much more dramatic intervention.

而是人們覺得注射是種更強力的手段

So we know that our beliefs and expectations

我們曉得自己的信念，期待

can be manipulated,

是可被操控的

which is why we do trials

這也為什麼我們做實驗時

where we control against a placebo --

需要拿安慰劑來對照

where one half of the people get the real treatment

一半的人接受真正的治療

and the other half get placebo.

另一半的人則使用安慰劑

But that's not enough.

但，這樣是不夠的

What I've just shown you are examples of the very simple and straightforward ways

目前為止，我給你們看的實驗例子的方法，都很簡單易懂

that journalists and food supplement pill peddlers

簡單到記者、食物供應商、糖果小販

and naturopaths

以及自然療法醫生

can distort evidence for their own purposes.

都可以根據他們自己的目的，來曲解證據

What I find really fascinating

令我相當驚訝的

is that the pharmaceutical industry

是那些醫藥工業

uses exactly the same kinds of tricks and devices,

他們使用相同的方法、設備

but slightly more sophisticated versions of them,

只不過把證據扭曲成較複雜的版本

in order to distort the evidence that they give to doctors and patients,

而醫生及病人，都根據那些扭曲的證據

and which we use to make vitally important decisions.

做出攸關性命的重要決定

So firstly, trials against placebo:

首先，大家都認為

everybody thinks they know that a trial should be

一個和安慰劑對照的實驗，應該是

a comparison of your new drug against placebo.

拿新藥品和安慰劑來相比較

But actually in a lot of situations that's wrong.

但，在很多情況下，這樣的方法是錯的

Because often we already have a very good treatment that is currently available,

因為，我們通常已經有了一個可行的良好療法

so we don't want to know that your alternative new treatment

我們就不需要知道那可有可無的

is better than nothing.

替代療法

We want to know that it's better than the best currently available treatment that we have.

我們想知道的是，替代療法是否比現行的最佳療法更好

And yet, repeatedly, you consistently see people doing trials

然而，你卻看到人們一再地

still against placebo.

拿安慰劑來對照做實驗

And you can get license to bring your drug to market

只要你得到許可證，你的藥品就可以上市

with only data showing that it's better than nothing,

藥品背後的數據，證明這種藥物可有可無

which is useless for a doctor like me trying to make a decision.

對一個像我這樣需要做決定的醫生來說是沒有任何用處的

But that's not the only way you can rig your data.

而這不是唯一可以扭曲數據的方法

You can also rig your data

你還可以把和新藥品要比較的物品

by making the thing you compare your new drug against

弄得像垃圾一樣

really rubbish.

毫無價值

You can give the competing drug in too low a dose,

在使用競爭者的藥品時，你也可以只給予很少的劑量，

so that people aren't properly treated.

而人們自然沒有辦法治療好

You can give the competing drug in too high a dose,

或是你把劑量提高

so that people get side effects.

這樣就會產生副作用

And this is exactly what happened

而這正是發生在治療人格分裂症的

which antipsychotic medication for schizophrenia.

抗精神病療程的事情

20 years ago, a new generation of antipsychotic drugs were brought in

二十年前，從國外引進了一批新的抗精神病藥物

and the promise was that they would have fewer side effects.

這些藥物都保證副作用比現有的藥物還少

So people set about doing trials of these new drugs

所以人們就開始拿這些新的藥物和舊的藥物

against the old drugs,

做實驗比較

but they gave the old drugs in ridiculously high doses --

但，他們卻把舊的藥物劑量提高很多－

20 milligrams a day of haloperidol.

一天要吃20毫克的施寧錠(抗精神病藥物)

And it's a foregone conclusion,