[Sleeping with Science]

[與科學共眠]

Now, Alzheimer's disease is a form of dementia typified usually by memory loss and memory decline.

阿茨海默症是一種癡呆症，通常以記憶力減退和記憶力下降為代表。

And what we've started to understand is that there are several different proteins that seem to go awry in Alzheimer's disease.

我們已經開始了解的是，在阿茨海默症中似乎有幾種不同的蛋白質會出錯。

One of those proteins is a sticky, toxic substance called beta-amyloid that builds up in the brain.

其中一種蛋白質是一種有粘性的有毒物質，稱為 β-澱粉樣蛋白，會在大腦中堆積。

The other is something called tau protein.

另一種是叫做 Tau 蛋白的東西。

How are these things related to sleep?

這些東西與睡眠有什麼關聯？

Well, first, if we look at a large-scale epidemiological level, what we know is that individuals who report sleeping typically less than six hours a night,

首先，如果我們從大規模的流行病學數量來看，我們知道的是，每晚睡眠時間通常少於六小時的人，

have a significantly higher risk of going on to develop high amounts of that beta-amyloid in their brain later in life.

在往後的生活中，他們的大腦中持續產生大量 β-澱粉樣蛋白的風險比常人要高得多。

We also know that two sleep disorders, including insomnia and sleep apnea, or heavy snoring, are associated with a significantly higher risk of Alzheimer's disease in late life.

我們還知道，包括失眠和睡眠呼吸中止症或嚴重的打鼾在內的兩種睡眠障礙與晚年患阿茨海默症的風險顯著增加有關。

Those are, of course, simply associational studies.

當然，這些都是簡單的關聯研究。

They don't prove causality.

不能證明其因果關係。

But more recently, we actually have identified that causal evidence.

但最近，我們其實已經確定了它們之間的因果證據。

In fact, if you take a healthy human being and you deprive them of sleep for just one night, and the next day, we see an immediate increase in that beta-amyloid,

事實上，如果你讓一個健康的人一個晚上不睡覺，第二天，我們就會看到 β-澱粉樣蛋白立即增加，

both circulating in their bloodstream, circulating in what we call the cerebrospinal fluid,

兩者都在他們的血液中循環，在我們所說的腦脊液中循環，

and most recently, after just one night of sleep, using special brain-imaging technology,

最近，在只睡了一晚之後，使用特殊的大腦成像技術，

scientists have found that there is an immediate increase in beta-amyloid directly in the brain itself.

科學家們發現，大腦本身的 β-澱粉樣蛋白會立即增加。

So that's the causal evidence.

所以這就是因果證據。

What is it then about sleep that seems to provide a mechanism that prevents the escalation of these Alzheimer's-related proteins?

睡眠是提供了什麼樣的機制來阻止這些阿茨海默症相關的蛋白質增加呢？

Well, several years ago, a scientist called Maiken Nedergaard made a remarkable discovery.

在幾年前，Maiken Nedergaard 有一個令人注目的發現。

What she identified was a cleansing system in the brain.

她發現大腦中的一個清潔系統。

Now, before that, we knew that the body had a cleansing system and many of you may be familiar with this.

在近一步說明之前，我們知道身體有一個清潔系統，你們很多人可能對此很熟悉，

It's called the lymphatic system.

就是所謂的淋巴系統。

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

但我們並不知道大腦也有自己的清潔系統。

And studying mice, she was actually able to identify a sewage system within the brain called the glymphatic system,

透過研究老鼠，她識別出大腦中一個叫做淋巴系統的清潔系統，

named after the cells that make it up, called these glial cells.

其名字以組成它的細胞，神經膠質細胞命名。

Now, if that wasn't remarkable enough, she went on to make two more incredible discoveries.

如果這發現還不夠傑出的話，她還接續做出兩個更令人難以置信的發現。

First, what she found is that that cleansing system in the brain is not always switched on in high-flow volume across the 24-hour period.

首先，她發現大腦中的清潔系統並不總是在 24 小時內以高流量運作。

Instead, it was when those mice were actually sleeping, particularly when they went into deep non-REM sleep, that that cleansing system kicked into high gear.

反之，是當這些老鼠睡覺時，尤其是當它們進入深度非快速眼動期時，清潔系統才開始高速運作。

The third component that she discovered, and this is what makes it relevant to our discussion on Alzheimer's disease,

她發現的第三個組成部分，也就是與我們討論阿茨海默症相關的原因，

is that one of the metabolic by-products, one of the toxins that was cleared away during sleep, was that sticky, toxic protein, beta-amyloid, linked to Alzheimer's disease.

她發現一種代謝副產物，一種在睡眠期間被清除的毒素，是與阿茨海默症有關的有黏性、有毒蛋白質、β-澱粉樣蛋白。

And just recently, scientists in Boston have discovered a very similar type of pulsing, cleansing brain-mechanism in human beings as well.

就在最近，波士頓的科學家們也在人類身上發現了一種非常相似的脈衝、清潔大腦機制。

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

有些討論聽起來可能有點令人沮喪。

We know that as we get older in life, our sleep seems to typically decline, and our risk for Alzheimer's generally increases.

我們知道，隨著年齡的增長，我們的睡眠品質似乎通常會下降，而我們患阿茨海默症的風險通常會增加。

But I think there's actually a silver lining here, because unlike many of the other factors that are associated with aging and Alzheimer's disease,

但我認為其實還有一線希望，因為與許多其他與衰老和阿茨海默症相關的因素不同，

for example, changes in the physical structure of the brain, those are fiendishly difficult to treat and medicine doesn't have any good wholesale approaches right now.

例如，大腦物理結構的變化，這些非常難以治療，而醫學目前還沒有任何有效的治療方法。

But that sleep is a missing piece in the explanatory puzzle of aging and Alzheimer's disease is exciting because we may be able to do something about it.

但睡眠是衰老和阿茨海默症謎團中缺失的一部分，這很令人興奮，因為我們也許可以對此做點什麼。

What if we could actually augment human sleep and try to improve the quality of that deep sleep in midlife, which is when we start to see the decline in deep sleep beginning to happen.

如果我們可以增加人類睡眠並嘗試改善中年時，也就是深度睡眠開始下降時的睡眠品質會發生什麼事？

What if we could actually shift from a model of late-stage treatment in Alzheimer's disease to a model of midlife prevention?

如果我們真的可以從阿茨海默症的末期治療轉變為中年就開始預防呢？

Could we go from sick care to actually healthcare?

我們將疾病治療轉變為醫療保健嗎？

And by modifying sleep, could we actually bend the arrow of Alzheimer's disease risk down on itself?

透過改變睡眠，我們真的可以將阿茨海默症風險的風險降低嗎

That's something that I'm incredibly excited about and something that we're actively researching right now.

這是我非常期待的事情，也是我們現在正在積極研究的事情。