What's the connection between sleep and Alzheimer's disease?
-
0:00 - 0:03We're now becoming aware
of a significant relationship -
0:04 - 0:06between sleep and Alzheimer's disease.
-
0:07 - 0:09[Sleeping with Science]
-
0:11 - 0:15Now, Alzheimer's disease
is a form of dementia -
0:15 - 0:19typified usually by memory loss
and memory decline. -
0:20 - 0:21And what we've started to understand
-
0:21 - 0:24is that there are several
different proteins -
0:24 - 0:28that seem to go awry
in Alzheimer's disease. -
0:28 - 0:31One of those proteins
is a sticky, toxic substance -
0:31 - 0:34called beta-amyloid
that builds up in the brain. -
0:34 - 0:37The other is something called tau protein.
-
0:37 - 0:40How are these things related to sleep?
-
0:40 - 0:45Well first, if we look at a large-scale
epidemiological level, -
0:45 - 0:47what we know is that individuals
-
0:47 - 0:51who report sleeping typically
less than six hours a night, -
0:51 - 0:53have a significantly higher risk
-
0:53 - 0:55of going on to develop high amounts
-
0:55 - 0:58of that beta-amyloid
in their brain later in life. -
0:58 - 1:02We also know that two sleep disorders,
-
1:02 - 1:06including insomnia and sleep apnea,
or heavy snoring, -
1:06 - 1:09are associated with
a significantly higher risk -
1:09 - 1:12of Alzheimer's disease in late life.
-
1:12 - 1:16Those are, of course,
simply associational studies. -
1:16 - 1:18They don't prove causality.
-
1:18 - 1:19But more recently,
-
1:19 - 1:23we actually have identified
that causal evidence. -
1:24 - 1:27In fact, if you take a healthy human being
-
1:27 - 1:30and you deprive them
of sleep for just one night, -
1:30 - 1:33and the next day,
we see an immediate increase -
1:33 - 1:35in that beta-amyloid,
-
1:35 - 1:37both circulating in their bloodstream,
-
1:37 - 1:41circulating in what we call
the cerebrospinal fluid, -
1:41 - 1:44and most recently,
after just one night of sleep, -
1:44 - 1:47using special brain-imaging technology,
-
1:47 - 1:50scientists have found
that there is an immediate increase -
1:50 - 1:53in beta-amyloid
directly in the brain itself. -
1:53 - 1:56So that's the causal evidence.
-
1:56 - 1:58What is it then about sleep
-
1:58 - 2:00that seems to provide a mechanism
-
2:00 - 2:03that prevents the escalation
-
2:03 - 2:05of these Alzheimer's-related proteins?
-
2:06 - 2:07Well, several years ago,
-
2:07 - 2:10a scientist called Maiken Nedergaard
-
2:10 - 2:13made a remarkable discovery.
-
2:13 - 2:17What she identified
was a cleansing system in the brain. -
2:18 - 2:19Now, before that,
-
2:19 - 2:22we knew that the body
had a cleansing system -
2:22 - 2:24and many of you may be familiar with this.
-
2:24 - 2:26It's called the lymphatic system.
-
2:26 - 2:30But we didn't think that the brain
had its own cleansing system. -
2:30 - 2:32And studying mice,
-
2:32 - 2:37she was actually able to identify
a sewage system within the brain -
2:37 - 2:40called the glymphatic system,
-
2:40 - 2:42named after the cells that make it up,
-
2:42 - 2:44called these glial cells.
-
2:44 - 2:46Now, if that wasn't remarkable enough,
-
2:46 - 2:49she went on to make
two more incredible discoveries. -
2:49 - 2:54First, what she found is that
that cleansing system in the brain -
2:54 - 2:58is not always switched on
in high-flow volume -
2:58 - 3:01across the 24-hour period.
-
3:01 - 3:04Instead, it was when those mice
were actually sleeping, -
3:04 - 3:07particularly when they went
into deep non-REM sleep, -
3:07 - 3:11that that cleansing system
kicked into high gear. -
3:11 - 3:14The third component that she discovered,
-
3:14 - 3:16and this is what makes it relevant
-
3:16 - 3:18to our discussion on Alzheimer's disease,
-
3:18 - 3:22is that one of the metabolic by-products,
-
3:22 - 3:25one of the toxins
that was cleared away during sleep, -
3:26 - 3:29was that sticky,
toxic protein, beta-amyloid, -
3:29 - 3:32linked to Alzheimer's disease.
-
3:32 - 3:36And just recently,
scientists in Boston have discovered -
3:36 - 3:41a very similar type of pulsing,
cleansing brain-mechanism -
3:41 - 3:43in human beings as well.
-
3:43 - 3:47Now, some of this discussion
may sound perhaps a little depressing. -
3:47 - 3:50We know that as we get older in life,
-
3:50 - 3:53our sleep seems to typically decline,
-
3:53 - 3:56and our risk for Alzheimer's
generally increases. -
3:56 - 3:58But I think there's actually
a silver lining here, -
3:58 - 4:01because unlike many of the other factors
-
4:01 - 4:04that are associated
with aging and Alzheimer's disease, -
4:04 - 4:07for example, changes
in the physical structure of the brain, -
4:07 - 4:10those are fiendishly difficult to treat
-
4:10 - 4:14and medicine doesn't have any good
wholesale approaches right now. -
4:14 - 4:18But that sleep is a missing piece
-
4:18 - 4:22in the explanatory puzzle
of aging and Alzheimer's disease -
4:22 - 4:26is exciting because we may be
able to do something about it. -
4:26 - 4:29What if we could actually
augment human sleep -
4:29 - 4:32and try to improve the quality
-
4:32 - 4:34of that deep sleep in midlife,
-
4:34 - 4:37which is when we start to see
the decline in deep sleep -
4:37 - 4:38beginning to happen.
-
4:38 - 4:40What if we could actually shift
-
4:40 - 4:45from a model of late-stage
treatment in Alzheimer's disease -
4:45 - 4:48to a model of midlife prevention?
-
4:48 - 4:52Could we go from sick care
to actually healthcare? -
4:52 - 4:54And by modifying sleep,
-
4:54 - 4:57could we actually bend the arrow
-
4:57 - 5:00of Alzheimer's disease risk
down on itself? -
5:00 - 5:04That's something
that I'm incredibly excited about -
5:04 - 5:07and something that we're actively
researching right now.
- Title:
- What's the connection between sleep and Alzheimer's disease?
- Speaker:
- Matt Walker
- Description:
-
Does not getting enough sleep lead to Alzheimer's disease? Sleep scientist Matt Walker explains the relationship between the two -- and how researchers are exploring how to use sleep to decrease our chances of developing this condition.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED Series
- Duration:
- 05:07
Erin Gregory approved English subtitles for What's the connection between sleep and Alzheimer's disease? | ||
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Ivana Korom edited English subtitles for What's the connection between sleep and Alzheimer's disease? | ||
Ivana Korom edited English subtitles for What's the connection between sleep and Alzheimer's disease? | ||
Brian Greene edited English subtitles for What's the connection between sleep and Alzheimer's disease? | ||
Brian Greene edited English subtitles for What's the connection between sleep and Alzheimer's disease? |