Why Alcohol & Coffee Taste Bad At First & Later Taste Good | Dr. Charles Zuker & Dr. Andrew Huberman
00:00:00.000 | kids don't seem to like certain vegetables, but they all are hardwired to like sweet tastes.
00:00:11.540 | And yet you could also imagine that one of the reasons why they may eventually grow to
00:00:16.480 | incorporate vegetables is because of some knowledge that vegetables might be better
00:00:20.920 | for them.
00:00:21.920 | So is there a change in the receptors, the distribution, the number, the sensitivity,
00:00:27.860 | et cetera, that can explain the transition from wanting to avoid vegetables to being
00:00:32.580 | willing to eat vegetables, simply in childhood to early development?
00:00:37.060 | I want to take the question slightly differently, but I think it would illustrate the point.
00:00:42.360 | And I want to just use the difference between the olfactory system and the taste system
00:00:49.780 | to make the point.
00:00:52.740 | Taste system, five basic palates, sweet, sour, bitter, salt, and umami.
00:00:56.700 | Each of them has a predetermined identity.
00:00:58.940 | We know exactly what, and valence.
00:01:01.820 | These are attractive.
00:01:02.980 | These are aversive.
00:01:04.760 | In the olfactory system, it's claimed that we can smell millions of different odors.
00:01:11.660 | Yet for the most part, none of them have an innate predetermined meaning.
00:01:20.340 | In the olfactory system, meaning is imposed by learning and experience.
00:01:26.500 | And the smell of smoke.
00:01:27.740 | So I'm going to give you, I'm going to make it differently.
00:01:30.940 | There are a handful of the millions of odors that were claimed that you could immediately
00:01:36.840 | tell me these are aversive and these are attractive.
00:01:42.140 | Vomit.
00:01:43.140 | So vomit, it's not correct because I can assure you that there are cultures and societies
00:01:50.460 | where things which are far less appealing than vomit do not evoke an aversive reaction.
00:01:56.380 | Really?
00:01:57.380 | Really.
00:01:58.380 | Sulfur would be maybe a universal.
00:02:00.260 | I'm not talking pheromones.
00:02:01.260 | Okay?
00:02:02.260 | Pheromones are in a different category that trigger innate responses.
00:02:06.940 | But nearly every other is afforded meaning by learning and experience.
00:02:14.500 | And that's why you like broccoli and I despise broccoli because I remember my mother forcing
00:02:21.200 | me to eat broccoli.
00:02:22.540 | I'm so sorry.
00:02:23.540 | It's the same sensory experience.
00:02:25.380 | Yeah.
00:02:26.380 | Alright.
00:02:27.380 | This, this accommodates two important things.
00:02:31.300 | In the case of taste, you have neurons at every station that are for sweet, for sour,
00:02:35.980 | for bitter, for salty and umami.
00:02:37.540 | It's only five classes.
00:02:39.180 | So it's not going to take a lot of your brain.
00:02:41.380 | If we can in fact smell a million odors and every one of those odors had to have predetermined
00:02:46.700 | meaning, there's not going to be enough brain just to accommodate that one sense.
00:02:54.020 | And so evolution in its infinite wisdom, it evolve a system where you put together a pathway
00:03:03.500 | and a cortex, olfactory cortex, where you have the capacity to associate every other
00:03:14.060 | in a specific context that now gives it the meaning.
00:03:19.560 | Now let's go back to the original question then.
00:03:24.100 | So other than clearly plastic, mega plastic, because it's, it's fundamental basis and neural
00:03:32.500 | organization, but taste, we just told you that it's, you know, predetermined hardwire,
00:03:37.620 | but predetermined hardwire, it doesn't mean that it's not modulated by learning or experience.
00:03:43.600 | It only means that you are born liking sweet and disliking bitter.
00:03:51.000 | And we have many examples of plasticity, beer being one example.
00:03:56.500 | So why do we learn to love beer?
00:03:58.700 | It's in coffee.
00:04:00.300 | It's because it has an associated gain to the system and that gain to the system, that
00:04:10.180 | positive valence that emerges out of that negative signal is sufficient to create that
00:04:17.580 | positive association.
00:04:19.540 | And in the case of beer, of course, it's alcohol.
00:04:22.980 | The feeling good that we get after is more than sufficient to say, I want to have more
00:04:28.240 | of this.
00:04:30.080 | And in the case of coffee, of course, it's caffeine activating a whole group of neurotransmitter
00:04:34.500 | systems that give you that, that, that high associated with coffee.
00:04:39.640 | So yes, this taste system is changeable.
00:04:42.340 | It's malleable and is subjected to learning and experience, but unlike the olfactory system
00:04:49.100 | is restricted in what you could do with it because its goal is to allow you to get nutrients
00:04:58.160 | and survive.
00:04:59.840 | The goal of the olfactory system is very different.
00:05:02.900 | It's being used, not in our case, but in every animal species to, you know, identify friend
00:05:08.560 | versus foe, to identify mate, to identify ecological niches they want to be in.
00:05:19.000 | So it plays a very broad role that then requires that it be set up, organized and function
00:05:28.000 | in a very different type of context.
00:05:30.980 | Taste is about, can we get the nutrients we need to survive?
00:05:35.440 | And can we ensure that we are attracted to the ones we need and we are averse to the
00:05:39.840 | ones that are going to kill us?
00:05:41.360 | [music]