Heribert Watzke: The brain in your gut

231,230 views ・ 2010-10-19

TED


Please double-click on the English subtitles below to play the video.

00:16
This technology
0
16260
2000
00:18
made a very important impact on us.
1
18260
2000
00:20
It changed the way our history developed.
2
20260
3000
00:24
But it's a technology so pervasive,
3
24260
2000
00:26
so invisible,
4
26260
2000
00:28
that we, for a long time,
5
28260
2000
00:30
forgot to take it into account
6
30260
3000
00:33
when we talked about
7
33260
2000
00:35
human evolution.
8
35260
2000
00:37
But we see the results of this technology, still.
9
37260
3000
00:40
So let's make a little test.
10
40260
2000
00:42
So everyone of you turns to their neighbor please.
11
42260
3000
00:46
Turn and face your neighbors.
12
46260
2000
00:48
Please, also on the balcony.
13
48260
3000
00:51
Smile. Smile. Open the mouths.
14
51260
2000
00:53
Smile, friendly.
15
53260
2000
00:55
(Laughter)
16
55260
2000
00:57
Do you --
17
57260
2000
00:59
Do you see any Canine teeth?
18
59260
3000
01:02
(Laughter)
19
62260
2000
01:04
Count Dracula teeth
20
64260
3000
01:07
in the mouths of your neighbors?
21
67260
2000
01:09
Of course not.
22
69260
2000
01:11
Because our dental anatomy
23
71260
3000
01:14
is actually made,
24
74260
2000
01:16
not for tearing down raw meat from bones
25
76260
3000
01:19
or chewing fibrous leaves for hours.
26
79260
3000
01:24
It is made for a diet
27
84260
2000
01:26
which is soft, mushy,
28
86260
3000
01:29
which is reduced in fibers,
29
89260
3000
01:32
which is very easily chewable
30
92260
2000
01:34
and digestible.
31
94260
3000
01:37
Sounds like fast food, doesn't it.
32
97260
2000
01:39
(Laughter)
33
99260
2000
01:41
It's for cooked food.
34
101260
3000
01:44
We carry in our face the proof
35
104260
2000
01:47
that cooking,
36
107260
2000
01:49
food transformation,
37
109260
3000
01:52
made us what we are.
38
112260
2000
01:54
So I would suggest that we change how we classify ourselves.
39
114260
3000
01:57
We talk about ourselves as omnivores.
40
117260
3000
02:00
I would say, we should call ourselves coctivors --
41
120260
3000
02:03
(Laughter)
42
123260
2000
02:05
from coquere, to cook.
43
125260
3000
02:08
We are the animals
44
128260
2000
02:10
who eat cooked food.
45
130260
3000
02:13
No, no, no, no. Better --
46
133260
2000
02:15
to live of cooked food.
47
135260
2000
02:17
So cooking is a very important technology.
48
137260
2000
02:19
It's technology.
49
139260
2000
02:21
I don't know how you feel,
50
141260
2000
02:23
but I like to cook for entertainment.
51
143260
2000
02:25
And you need some design
52
145260
2000
02:27
to be successful.
53
147260
2000
02:29
So, cooking is a very important technology,
54
149260
3000
02:32
because it allowed us to acquire
55
152260
3000
02:35
what brought you all here:
56
155260
3000
02:38
the big brain,
57
158260
2000
02:40
this wonderful cerebral cortex we have.
58
160260
3000
02:43
Because brains are expensive.
59
163260
3000
02:46
Those have to pay tuition fees know.
60
166260
3000
02:49
(Laughter)
61
169260
2000
02:51
But it's also, metabolically speaking, expensive.
62
171260
3000
02:55
You now, our brain is two to three percent of the body mass,
63
175260
3000
02:58
but actually it uses 25 percent of the total energy we use.
64
178260
3000
03:01
It's very expensive.
65
181260
2000
03:03
Where does the energy come from. Of course, from food.
66
183260
3000
03:06
If we eat raw food,
67
186260
2000
03:08
we cannot release really the energy.
68
188260
3000
03:12
So this ingenuity of our ancestors,
69
192260
3000
03:15
to invent this most marvelous technology.
70
195260
3000
03:18
Invisible -- everyone of us does it every day, so to speak.
71
198260
4000
03:22
Cooking made it possible
72
202260
2000
03:24
that mutations,
73
204260
2000
03:26
natural selections, our environment,
74
206260
2000
03:28
could develop us.
75
208260
3000
03:32
So if we think about
76
212260
2000
03:34
this unleashing human potential,
77
214260
3000
03:37
which was possible by cooking and food,
78
217260
3000
03:40
why do we talk so badly about food?
79
220260
3000
03:43
Why is it always do and don'ts
80
223260
2000
03:45
and it's good for you, it's not good for you?
81
225260
2000
03:47
I think the good news for me
82
227260
2000
03:49
would be if we could go back
83
229260
3000
03:52
and talk about the unleashing,
84
232260
2000
03:54
the continuation of the unleashing of human potential.
85
234260
3000
03:57
Now, cooking allowed also
86
237260
2000
03:59
that we became a migrant species.
87
239260
3000
04:02
We walked out of Africa two times.
88
242260
3000
04:05
We populated all the ecologies.
89
245260
2000
04:07
If you can cook, nothing can happen to you,
90
247260
3000
04:10
because whatever you find,
91
250260
2000
04:12
you will try to transform it.
92
252260
2000
04:14
It keeps also your brain working.
93
254260
3000
04:17
Now the very easy and simple technology
94
257260
4000
04:21
which was developed
95
261260
2000
04:23
actually runs after this formula.
96
263260
2000
04:25
Take something which looks like food, transform it,
97
265260
3000
04:28
and it gives you a good, very easy, accessible energy.
98
268260
3000
04:31
This technology affected two organs,
99
271260
3000
04:34
the brain and the gut, which it actually affected.
100
274260
3000
04:37
The brain could grow, but the gut actually shrunk.
101
277260
3000
04:40
Okay, it's not obvious to be honest.
102
280260
2000
04:42
(Laughter)
103
282260
3000
04:45
But it shrunk to 60 percent
104
285260
2000
04:47
of primate gut
105
287260
2000
04:49
of my body mass.
106
289260
2000
04:51
So because of having cooked food,
107
291260
3000
04:54
it's easier to digest.
108
294260
3000
04:57
Now having a large brain, as you know,
109
297260
3000
05:00
is a big advantage,
110
300260
2000
05:02
because you can actually influence your environment.
111
302260
3000
05:05
You can influence your own technologies you have invented.
112
305260
2000
05:07
You can continue to innovate and invent.
113
307260
2000
05:09
Now the big brain did this also with cooking.
114
309260
3000
05:12
But how did it actually run this show?
115
312260
3000
05:15
How did it actually interfere?
116
315260
2000
05:17
What kind of criteria did it use?
117
317260
3000
05:20
And this is actually taste reward and energy.
118
320260
4000
05:24
You know we have up to five tastes,
119
324260
2000
05:26
three of them sustain us.
120
326260
3000
05:29
Sweet -- energy.
121
329260
2000
05:31
Umami -- this is a meaty taste.
122
331260
2000
05:33
You need proteins for muscles, recovery.
123
333260
3000
05:37
Salty,
124
337260
2000
05:39
because you need salt, otherwise your electric body will not work.
125
339260
3000
05:42
And two tastes which protect you --
126
342260
3000
05:45
bitter and sour,
127
345260
2000
05:47
which are against
128
347260
3000
05:50
poisonous and rotten material.
129
350260
3000
05:53
But of course, they are hard-wired
130
353260
2000
05:55
but we use them still in a sophisticated way.
131
355260
2000
05:57
Think about bittersweet chocolate;
132
357260
2000
05:59
or think about the acidity
133
359260
2000
06:01
of yogurt -- wonderful --
134
361260
2000
06:03
mixed with strawberry fruits.
135
363260
2000
06:05
So we can make mixtures of all this kind of thing
136
365260
3000
06:08
because we know
137
368260
3000
06:11
that, in cooking, we can transform it
138
371260
2000
06:13
to the form.
139
373260
2000
06:15
Reward: this is a more complex
140
375260
3000
06:18
and especially integrative
141
378260
3000
06:21
form of our brain
142
381260
2000
06:23
with various different elements --
143
383260
3000
06:26
the external states, our internal states,
144
386260
2000
06:28
how do we feel, and so on are put together.
145
388260
3000
06:31
And something which maybe you don't like
146
391260
2000
06:33
but you are so hungry that you really will be satisfied to eat.
147
393260
3000
06:36
So satisfaction was a very important part.
148
396260
3000
06:39
And as I say, energy was necessary.
149
399260
2000
06:41
Now how did the gut actually
150
401260
2000
06:43
participate in this development?
151
403260
3000
06:46
And the gut is a silent voice --
152
406260
3000
06:49
it's going more for feelings.
153
409260
2000
06:51
I use the euphemism digestive comfort --
154
411260
3000
06:55
actually -- it's a digestive discomfort,
155
415260
3000
06:58
which the gut is concerned with.
156
418260
3000
07:01
If you get a stomach ache, if you get a little bit bloated,
157
421260
3000
07:04
was not the right food, was not the right cooking manipulation
158
424260
3000
07:07
or maybe other things went wrong.
159
427260
2000
07:09
So my story is a tale of two brains,
160
429260
3000
07:12
because it might surprise you,
161
432260
2000
07:14
our gut has a full-fledged brain.
162
434260
3000
07:17
All the managers in the room say,
163
437260
2000
07:19
"You don't tell me something new, because we know, gut feeling.
164
439260
2000
07:21
This is what we are using."
165
441260
2000
07:23
(Laughter)
166
443260
2000
07:25
And actually you use it and it's actually useful.
167
445260
2000
07:27
Because our gut is connected to our emotional limbic system,
168
447260
3000
07:30
they do speak with each other
169
450260
2000
07:32
and make decisions.
170
452260
2000
07:35
But what it means
171
455260
2000
07:37
to have a brain there
172
457260
2000
07:39
is that, not only the big brain
173
459260
3000
07:42
has to talk with the food,
174
462260
3000
07:45
the food has to talk with the brain,
175
465260
3000
07:48
because we have to learn actually
176
468260
3000
07:51
how to talk to the brains.
177
471260
2000
07:53
Now if there's a gut brain,
178
473260
2000
07:55
we should also learn to talk with this brain.
179
475260
2000
07:57
Now 150 years ago,
180
477260
2000
07:59
anatomists described very, very carefully --
181
479260
3000
08:02
here is a model of a wall of a gut.
182
482260
3000
08:05
I took the three elements --
183
485260
2000
08:07
stomach, small intestine and colon.
184
487260
3000
08:10
And within this structure,
185
490260
2000
08:12
you see these two pinkish layers,
186
492260
2000
08:14
which are actually the muscle.
187
494260
2000
08:16
And between this muscle, they found nervous tissues,
188
496260
2000
08:18
a lot of nervous tissues,
189
498260
2000
08:20
which penetrate actually the muscle --
190
500260
2000
08:22
penetrate the submucosa,
191
502260
2000
08:24
where you have all the elements for the immune system.
192
504260
2000
08:26
The gut is actually the largest immune system,
193
506260
2000
08:28
defending your body.
194
508260
2000
08:30
It penetrates the mucosa.
195
510260
2000
08:32
This is the layer which actually touches the food you are swallowing
196
512260
3000
08:35
and you digest,
197
515260
2000
08:37
which is actually the lumen.
198
517260
2000
08:39
Now if you think about the gut,
199
519260
2000
08:41
the gut is -- if you could stretch it --
200
521260
2000
08:43
40 meters long,
201
523260
2000
08:45
the length of a tennis court.
202
525260
2000
08:47
If we could unroll it,
203
527260
2000
08:49
get out all the folds and so on,
204
529260
3000
08:52
it would have 400 sq. meters of surface.
205
532260
3000
08:55
And now this brain takes care over this,
206
535260
3000
08:58
to move it with the muscles and to do defend the surface
207
538260
3000
09:01
and, of course, digest our food we cook.
208
541260
3000
09:04
So if we give you a specification,
209
544260
3000
09:07
this brain, which is autonomous,
210
547260
2000
09:09
have 500 million nerve cells,
211
549260
2000
09:11
100 million neurons --
212
551260
2000
09:13
so around the size of a cat brain,
213
553260
3000
09:16
so there sleeps a little cat --
214
556260
3000
09:19
thinks for itself,
215
559260
2000
09:21
optimizes whatever it digests.
216
561260
3000
09:24
It has 20 different neuron types.
217
564260
3000
09:27
It's got the same diversity you find actually in a pig brain,
218
567260
2000
09:29
where you have 100 billion neurons.
219
569260
3000
09:32
It has autonomous organized microcircuits,
220
572260
3000
09:35
has these programs which run.
221
575260
2000
09:37
It senses the food; it knows exactly what to do.
222
577260
3000
09:40
It senses it by chemical means
223
580260
2000
09:42
and very importantly by mechanical means,
224
582260
3000
09:45
because it has to move the food --
225
585260
2000
09:47
it has to mix all the various elements
226
587260
2000
09:49
which we need for digestion.
227
589260
2000
09:51
This control of muscle is very, very important,
228
591260
3000
09:54
because, you know, there can be reflexes.
229
594260
2000
09:56
If you don't like a food, especially if you're a child, you gag.
230
596260
3000
09:59
It's this brain which makes this reflex.
231
599260
2000
10:01
And then finally,
232
601260
2000
10:03
it controls also the secretion of this molecular machinery,
233
603260
3000
10:06
which actually digests the food we cook.
234
606260
3000
10:09
Now how do the two brains work with each other?
235
609260
3000
10:12
I took here a model from robotics --
236
612260
3000
10:15
it's called the Subsumption Architecture.
237
615260
3000
10:18
What it means is that we have a layered control system.
238
618260
3000
10:21
The lower layer, our gut brain,
239
621260
2000
10:23
has its own goals -- digestion defense --
240
623260
3000
10:26
and we have the higher brain
241
626260
2000
10:28
with the goal of integration
242
628260
2000
10:30
and generating behaviors.
243
630260
2000
10:32
Now both look -- and this is the blue arrows --
244
632260
3000
10:35
both look to the same food, which is in the lumen
245
635260
3000
10:38
and in the area of your intestine.
246
638260
2000
10:40
The big brain integrates signals,
247
640260
2000
10:42
which come from the running programs
248
642260
2000
10:44
of the lower brain,
249
644260
2000
10:46
But subsumption means
250
646260
2000
10:48
that the higher brain can interfere with the lower.
251
648260
3000
10:51
It can replace,
252
651260
2000
10:53
or it can inhibit actually, signals.
253
653260
3000
10:56
So if we take two types of signals --
254
656260
2000
10:58
a hunger signal for example.
255
658260
2000
11:00
If you have an empty stomach,
256
660260
2000
11:02
your stomach produces a hormone called ghrelin.
257
662260
2000
11:04
It's a very big signal;
258
664260
2000
11:06
it's sent to the brain says,
259
666260
2000
11:08
"Go and eat."
260
668260
2000
11:10
You have stop signals --
261
670260
2000
11:12
we have up to eight stop signals.
262
672260
2000
11:14
At least in my case,
263
674260
2000
11:16
they are not listened to.
264
676260
2000
11:18
(Laughter)
265
678260
2000
11:20
So what happens
266
680260
2000
11:22
if the big brain in the integration
267
682260
3000
11:25
overrides the signal?
268
685260
2000
11:27
So if you override the hunger signal,
269
687260
2000
11:29
you can have a disorder, which is called anorexia.
270
689260
3000
11:32
Despite generating
271
692260
2000
11:34
a healthy hunger signal,
272
694260
2000
11:36
the big brain ignores it
273
696260
2000
11:38
and activates different programs in the gut.
274
698260
3000
11:41
The more usual case
275
701260
2000
11:43
is overeating.
276
703260
3000
11:46
It actually takes the signal
277
706260
3000
11:49
and changes it,
278
709260
2000
11:51
and we continue,
279
711260
2000
11:53
even [though] our eight signals would say, "Stop, enough.
280
713260
3000
11:56
We have transferred enough energy."
281
716260
2000
11:58
Now the interesting thing is that,
282
718260
2000
12:00
along this lower layer -- this gut --
283
720260
2000
12:02
the signal becomes stronger and stronger
284
722260
3000
12:05
if undigested, but digestible, material
285
725260
3000
12:08
could penetrate.
286
728260
2000
12:10
This we found from bariatric surgery.
287
730260
3000
12:14
That then the signal would be very, very high.
288
734260
3000
12:17
So now back to the cooking question
289
737260
3000
12:20
and back to the design.
290
740260
2000
12:22
We have learned to talk to the big brain --
291
742260
3000
12:25
taste and reward, as you know.
292
745260
2000
12:27
Now what would be the language
293
747260
2000
12:29
we have to talk to the gut brain
294
749260
2000
12:31
that its signals are so strong
295
751260
2000
12:33
that the big brain cannot ignore it?
296
753260
3000
12:36
Then we would generate something
297
756260
2000
12:38
all of us would like to have --
298
758260
2000
12:40
a balance between the hunger
299
760260
2000
12:42
and the satiation.
300
762260
3000
12:45
Now I give you, from our research, a very short claim.
301
765260
3000
12:48
This is fat digestion.
302
768260
2000
12:50
You have on your left
303
770260
2000
12:52
an olive oil droplet,
304
772260
2000
12:54
and this olive oil droplet gets attacked by enzymes.
305
774260
3000
12:57
This is an in vitro experiment.
306
777260
2000
12:59
It's very difficult to work in the intestine.
307
779260
3000
13:02
Now everyone would expect
308
782260
2000
13:04
that when the degradation of the oil happens,
309
784260
2000
13:06
when the constituents are liberated,
310
786260
2000
13:08
they disappear, they go away
311
788260
2000
13:10
because they [were] absorbed.
312
790260
2000
13:12
Actually, what happens is that a very intricate structure appears.
313
792260
3000
13:15
And I hope you can see
314
795260
2000
13:17
that there are some ring-like structures in the middle image,
315
797260
2000
13:19
which is water.
316
799260
2000
13:21
This whole system generates a huge surface
317
801260
3000
13:24
to allow more enzymes
318
804260
2000
13:26
to attack the remaining oil.
319
806260
2000
13:28
And finally, on your right side,
320
808260
2000
13:30
you see a bubbly,
321
810260
2000
13:32
cell-like structure appearing,
322
812260
2000
13:34
from which the body will absorb the fat.
323
814260
3000
13:38
Now if we could take this language --
324
818260
2000
13:40
and this is a language of structures --
325
820260
3000
13:43
and make it longer-lasting,
326
823260
3000
13:46
that it can go through
327
826260
2000
13:48
the passage of the intestine,
328
828260
3000
13:51
it would generate stronger signals.
329
831260
3000
13:55
So our research --
330
835260
2000
13:57
and I think the research also at the universities --
331
837260
2000
13:59
are now fixing on these points
332
839260
2000
14:01
to say: how can we actually --
333
841260
2000
14:03
and this might sound trivial now to you --
334
843260
2000
14:05
how can we change cooking?
335
845260
2000
14:07
How can we cook
336
847260
2000
14:09
that we have this language developed?
337
849260
3000
14:12
So what we have actually, it's not an omnivore's dilemma.
338
852260
3000
14:15
We have a coctivor's opportunity,
339
855260
3000
14:18
because we have learned over the last two million years
340
858260
3000
14:21
which taste and reward --
341
861260
3000
14:24
quite sophisticated to cook --
342
864260
2000
14:26
to please ourselves, to satisfy ourselves.
343
866260
2000
14:28
If we add the matrix,
344
868260
2000
14:30
if we add the structure language, which we have to learn,
345
870260
3000
14:33
when we learn it, then we can put it back;
346
873260
2000
14:35
and around energy,
347
875260
2000
14:37
we could generate a balance,
348
877260
2000
14:39
which comes out
349
879260
2000
14:41
from our really primordial operation: cooking.
350
881260
3000
14:45
So, to make cooking really
351
885260
3000
14:48
a very important element,
352
888260
2000
14:50
I would say even philosophers have to change
353
890260
2000
14:52
and have to finally recognize
354
892260
2000
14:54
that cooking is what made us.
355
894260
3000
14:57
So I would say, coquo ergo sum:
356
897260
3000
15:00
I cook, therefore I am.
357
900260
2000
15:02
Thank you very much.
358
902260
2000
15:04
(Applause)
359
904260
3000
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7