What's the connection between sleep and Alzheimer's disease? | Sleeping with Science, a TED series

Transcriber: TED Translators admin Reviewer: Ivana Korom

We're now becoming aware of a significant relationship

譯者: Regina Chu 審譯者: Yi-Ping Cho (Marssi)

我們現在開始注意到

睡眠與阿茲海默症間的重大關連

between sleep and Alzheimer's disease.

[Sleeping with Science]

【科學睡眠】

Now, Alzheimer's disease is a form of dementia

阿茲海默症是一種失智症

typified usually by memory loss and memory decline.

典型特徵通常為 記憶喪失和記憶力下降

And what we've started to understand

我們開始瞭解到

is that there are several different proteins

有幾種不同的蛋白質

that seem to go awry in Alzheimer's disease.

似乎在阿茲海默症中行徑怪異

One of those proteins is a sticky, toxic substance

其中一種蛋白質 是一種黏黏的有毒物質

called beta-amyloid that builds up in the brain.

稱為 β-類澱粉蛋白，會在腦部累積

The other is something called tau protein.

另外一種稱為 tau（濤）蛋白

How are these things related to sleep?

這幾個東西怎麼跟睡眠有關？

Well first, if we look at a large-scale epidemiological level,

第一，如果我們以 大規模的流行病學來看

what we know is that individuals

我們知道的是

說自己每晚通常睡不到六小時的人

who report sleeping typically less than six hours a night,

have a significantly higher risk

顯然有較高的風險

of going on to develop high amounts

會於晚年在腦中產生高量的

of that beta-amyloid in their brain later in life.

那種 β-類澱粉蛋白

We also know that two sleep disorders,

我們也知道有兩種睡眠障礙

including insomnia and sleep apnea, or heavy snoring,

包括失眠

及睡眠呼吸中止症，即嚴重打鼾

are associated with a significantly higher risk

也會明顯增高

of Alzheimer's disease in late life.

在晚年得到阿茲海默症的風險

Those are, of course, simply associational studies.

這些當然只是關聯分析

They don't prove causality.

沒有因果關係證明

But more recently,

但是最近

we actually have identified that causal evidence.

我們實際上已經證實了這種因果關係

In fact, if you take a healthy human being

事實上，如果你找個健康的人

and you deprive them of sleep for just one night,

不讓他好好睡一晚

and the next day, we see an immediate increase

隔天，我們就會立即看到

in that beta-amyloid,

β-類澱粉蛋白的量

both circulating in their bloodstream,

在血液循環中

circulating in what we call the cerebrospinal fluid,

及我們稱為腦脊液中增加

and most recently, after just one night of sleep,

最近，僅一晚不睡

using special brain-imaging technology,

使用特殊的腦成像技術

scientists have found that there is an immediate increase

科學家發現

β-類澱粉蛋白的量 就會在大腦本身中立即增加

in beta-amyloid directly in the brain itself.

So that's the causal evidence.

所以那就是因果證明

What is it then about sleep

那為什麼睡眠

that seems to provide a mechanism

似乎可以提供一種機制

that prevents the escalation

能避免讓與阿茲海默症

of these Alzheimer's-related proteins?

相關的蛋白質上升？

Well, several years ago,

幾年前

a scientist called Maiken Nedergaard

有位名為梅肯的科學家

made a remarkable discovery.

取得重大的發現

What she identified was a cleansing system in the brain.

她找到的是大腦內的一種排毒系統

Now, before that,

在那之前

we knew that the body had a cleansing system

我們知道身體有一個排毒系統

and many of you may be familiar with this.

你們很多人都對這個很熟悉

It's called the lymphatic system.

那就是淋巴系統

But we didn't think that the brain had its own cleansing system.

但是我們沒有想到 腦部也有自己的排毒系統

And studying mice,

她藉著研究老鼠

she was actually able to identify a sewage system within the brain

實際識別出大腦內的 「污水處理」系統

called the glymphatic system,

稱為膠狀淋巴系統

named after the cells that make it up,

這名字來自它的組成細胞

called these glial cells.

神經膠細胞

Now, if that wasn't remarkable enough,

如果那還不夠看

she went on to make two more incredible discoveries.

她又進一步取得了兩個更非凡的發現

First, what she found is that that cleansing system in the brain

第一，她發現到腦部的排毒系統

is not always switched on in high-flow volume

並非 24 小時都以高流量開著

across the 24-hour period.

Instead, it was when those mice were actually sleeping,

相反地，只有在老鼠好好睡覺時

particularly when they went into deep non-REM sleep,

尤其是在牠們進入 深度非快速動眼睡眠期後

that that cleansing system kicked into high gear.

才會啟動高流量的排毒系統

The third component that she discovered,

她發現的第三個部分

and this is what makes it relevant

也是跟我們討論 阿茲海默症有關的地方

to our discussion on Alzheimer's disease,

is that one of the metabolic by-products,

就是有某個代謝副產物

one of the toxins that was cleared away during sleep,

在睡眠中會被淨化的那種毒素

was that sticky, toxic protein, beta-amyloid,

就是那個黏黏的有毒蛋白質

與阿茲海默症有關的 β-類澱粉蛋白

linked to Alzheimer's disease.

And just recently, scientists in Boston have discovered

就在最近波士頓的科學家發現了

a very similar type of pulsing, cleansing brain-mechanism

在人類的大腦中也有一種 非常類似的脈衝排毒機制

in human beings as well.

Now, some of this discussion may sound perhaps a little depressing.

在討論中有些地方 可能聽起來讓人有點沮喪

We know that as we get older in life,

我們知道隨著年紀愈來愈大

our sleep seems to typically decline,

我們的睡眠似乎也跟著一起變差

and our risk for Alzheimer's generally increases.

我們得到阿茲海默症的風險也跟著增加

But I think there's actually a silver lining here,

但是我認為實際上還是有一線希望

because unlike many of the other factors

因為不像其它

that are associated with aging and Alzheimer's disease,

與衰老和阿茲海默症有關的眾多因素

for example, changes in the physical structure of the brain,

例如腦部物理結構的改變

those are fiendishly difficult to treat

那些很難治療

and medicine doesn't have any good wholesale approaches right now.

而且藥物也沒有提供什麼廣泛的好處

But that sleep is a missing piece

但是那個睡眠是

in the explanatory puzzle of aging and Alzheimer's disease

衰老與阿茲海默症的 關聯拼圖中缺失的那一塊

is exciting because we may be able to do something about it.

這點十分振奮人心 因為我們可能有解了

What if we could actually augment human sleep

我們能不能確實增強人類的睡眠

and try to improve the quality

試圖改善

of that deep sleep in midlife,

中年時期的深度睡眠品質？

which is when we start to see the decline in deep sleep

中年正是我們的深度睡眠

beginning to happen.

開始變差的時候

What if we could actually shift

我們能不能轉變模式

from a model of late-stage treatment in Alzheimer's disease

從在晚年治療阿茲海默症

to a model of midlife prevention?

轉變成在中年預防？

Could we go from sick care to actually healthcare?

我們能不能從疾病護理 轉變成健康護理？

And by modifying sleep,

藉著調整睡眠

could we actually bend the arrow

我們能不能

of Alzheimer's disease risk down on itself?

讓阿茲海默症的風險箭頭向下轉？

That's something that I'm incredibly excited about

那是我感到非常興奮的地方

and something that we're actively researching right now.

也是我們現在積極在研究的地方