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Chasing Life

Did you know that some people can taste colors and others have a hard time recognizing faces? This season on Chasing Life, Dr. Sanjay Gupta takes listeners beyond the basics of sight, sound, smell, taste and touch to explore unique sensory experiences. Discover why psychedelics might change your worldview, how animals perceive differently than humans, and how biases in taste might impact the future of food production.

Join us each week to marvel at how the rich landscape of sensory perception shapes our understanding of the world.

Dr. Sanjay Gupta

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Food for Thought, Literally
Chasing Life
Nov 15, 2022

Can you picture your favorite comfort food? Whether it’s a steaming bowl of your grandmother’s homemade soup or a chewy chocolate candy bar from your childhood, food evokes all sorts of emotions. But the way we experience food also depends on lots of different factors like smell, sound, texture, color and memory. On today’s episode, University of Kentucky Professor Dan Han, teaches us about a new and emerging field called neurogastronomy, and how this science could help us train our brains to gravitate toward healthier and more sustainable food. Also, we’ll head into the kitchen with a behind-the-scenes lesson on how to apply neurogastronomy to your Thanksgiving table with Atlanta chef Taria Camerino. 

Episode Transcript
Dr. Sanjay Gupta
00:00:03
In a spacious, light filled kitchen in Atlanta, Teresa Camerino is preparing a pair of dishes perfect for a Thanksgiving table.
Taria Camerino
00:00:11
Oh, my goodness. It's so beautiful.
Taria Camerino
00:00:16
You know what's great is I've never made this flavor before.
Dr. Sanjay Gupta
00:00:22
But what Taria is making isn't traditional Thanksgiving fare. There are dishes that she has developed herself by blending textures and flavors from multiple cultures and traditions....
Taria Camerino
00:00:34
We're going to make a cranberry marmalade, and I'm going to use black lime, which is a Middle Eastern food. Dehydrate the limes, and it makes them really sharp flavored. And then I have mandarin and sumac and pomegranate molasses. I'm also going to do roasted sweet potato with sorghum dragee. So candied sorghum, grain and pomegranates. And.... I don't remember what else was supposed to be on it. We're just going to kind of wing it.
Dr. Sanjay Gupta
00:01:12
Taria is a professional chef, so she's no stranger to improvising in the kitchen, whether she's deciding which ingredients to add to a dish or just how much water to pour into a scalding pan.
Taria Camerino
00:01:25
The water, as far as measuring goes, you want just enough to cover the top.
Dr. Sanjay Gupta
00:01:37
But when Taria creates dishes, she's very intentional as she moves around the kitchen. She's using all of her senses to decide what her next move should be. She carefully sniffs each of her ingredients one by one, and she listens, for example, to the cranberries bubbling on the stove in a pot to see when they'll be ready.
Taria Camerino
00:02:04
And so those are going to cook down. And then the cranberries will start to pop.
Dr. Sanjay Gupta
00:02:13
She watches closely as their color brightens as they cook.
Taria Camerino
00:02:17
It's this beautiful magenta color, right? Because the they've started to burst and they're breaking down. And then there's this nice actually, you know what it looks like when we have this this really awesome sunsets in Atlanta. They're like orange and red and pink. Yeah, it's that color. It's one of the most beautiful sunset colors. It's just amazing. It can make you cry.
Dr. Sanjay Gupta
00:02:45
It's not unusual for chefs to cook with all their senses, but there hasn't been a dedicated field of science exploring why these factors play such a big role in the way we eat, until now.
Professor Dan Han
00:03:00
So in the simplest terms, neurgastronomy is the science of how the brain perceives flavor relevant to what we eat, why we like what we eat, and how we eat.
Dr. Sanjay Gupta
00:03:11
That's Dan Han. And unlike Taria, he's not a chef. He's a scientist. In fact, he's one of the founding fathers of this new interdisciplinary field called neurogastronomy. It brings chefs and farmers and doctors and researchers together to the table, so to speak, with one common goal: to explore how the brain perceives flavor and how our other senses, our surroundings, even our memories affect the way we experience food.
Taria Camerino
00:03:40
And we have to listen with all of our senses. Right? It's not just taste and the way it makes us feel when we're in front of it. How does it smell? Do we feel excited? You know what is happening if we're paying attention to all of those senses. The body is naturally drawn to things that make it feel well.
Dr. Sanjay Gupta
00:04:00
And here's the really exciting part: professor Han and Taria believe it is possible to use this new field of science for real good. Imagine if you crave whole fruits and vegetables in the same way you might crave a chocolate bar chips, all because of how your brain perceives the food. On today's episode, we're going to explore how neurogastronomy can help us retrain our brains to crave healthier and more sustainable foods. Professor Hahn will guide us through some of the brain science and with Taria's help will give you some actionable tips that you might even be able to use at your own Thanksgiving table. But I want to be clear: this isn't about counting calories or restricting what you eat. Neurogastronomists aren't dietitians. They're not nutritionists. They're not necessarily telling you what to eat. They're telling you how to experience what you eat. So I hope you're hungry because today we're heading into the kitchen. I'm Dr. Sanjay Gupta, CNN's chief medical correspondent. And it's time to start Chasing Life.
Dr. Sanjay Gupta
00:05:07
For a while now, cooking, preparing and eating a meal has been viewed as more of an art than a science, understandably. But increasingly, researchers are exploring the ways in which we taste and perceive flavor. And as I mentioned, the field of neuro gastronomy, which brings together scientists and those in the culinary industry, is still fairly new.
Professor Dan Han
00:05:30
Dr. Gordon Shepherd, a legend in the field of neuroscience who recently passed, unfortunately, coined the term in 2006. In its publication in the journal Nature, he called for scientists to come out of their academic ivory tower silos. He called for that to end and then to create an interdisciplinary approach to address food perception.
Dr. Sanjay Gupta
00:05:52
When Professor Han learned about Dr. Shepherd's goal, he decided to take action. Han's day job is working as chief of the neuropsychology Division at UK Health Care in Kentucky and a professor at the University of Kentucky College of Medicine. But with the help of chefs and other scientists, he also co-founded the International Society of Neuro Gastronomy, an organization that has many goals and spans across disciplines.
Professor Dan Han
00:06:21
Neurogastronomy fundamentally asks scientists, clinicians like us, futurists, chefs and consumers of anything delicious to teach each other, to learn more about all aspects of flavor perception for humans. And you can see how such a challenge can address issues spanning from making food more delicious to efficient and effective nutrition intake for global health and agricultural sciences. What we're trying to aim for is to actually be true to ourselves and identify how flavor mechanism works and then change. How we can create a balance instead of overconsumption or, you know, over farming or what have you, but come up with scientific and evidence based ways so that we could perceive food the way we want to and have our kitchen needed to.
Dr. Sanjay Gupta
00:07:18
You know, it's that last part of what Dr. Hahn said that I found really important. Because, before we change our behaviors, we do have to first understand how taste and flavor actually work. So I asked him to give us a crash course on how we perceive flavor.
Dr. Sanjay Gupta
00:07:35
I want to dial in and talk about the mechanics, I guess, of what you're talking about, just so we can set the table in terms of what these interventions are, what these things are, and start off by this, you know, just explain the mechanics behind taste. We think of the tongue. We know the brain plays obviously a major role in this...
Professor Dan Han
00:07:53
Mm hmm.
Dr. Sanjay Gupta
00:07:54
...what we ultimately perceive, what is the mechanism behind taste?
Professor Dan Han
00:08:00
So I'm glad you brought that up, because that actually dives into what we're trying to achieve collectively. So let's digest it. And that was an unintended pun. Again, what we semantically consider taste is actually more aptly termed flavor. So you see flavor perception is actually 75 to 90% comprised of smell, not taste. So what you colloquially think of taste is actually flavor to a much lesser extent through the actual taste receptor cells on the tongue itself.
Dr. Sanjay Gupta
00:08:35
Let's just repeat that for one sec, because I think that is a fascinating concept. So taste is one component of flavor. And flavor involves many things, but the biggest thing is actually smell.
Professor Dan Han
00:08:50
Mm hmm.
Dr. Sanjay Gupta
00:08:50
So taste is one component of flavor, but not at all the largest component of flavor.
Professor Dan Han
00:08:57
Yes. And where it gets extra tricky in terms of the mechanism is that it's not as much inhalation of the smell, but it's the retronasal olfaction. It's just a fancy way of saying exhale. That exhalation is tingling your senses. I mean, if the audience doesn't believe me, try this: next time you're at a favorite restaurant or having a favorite meal, try chewing everything with your nose plugged. And don't breathe through your nose while you're chewing. And then you'll notice everything just get dense. And then, you know, before you choking me, don't choke, you know, exhale out. And then you'll notice a drastic difference in how the flavor profile changes in your mouth. And that is that 75% of flavor perception.
Dr. Sanjay Gupta
00:09:50
Look, I think that most people listening, myself included, knew that smell was a part of flavor. But I don't think I realized it was such a huge factor. And it's not just smell.
Professor Dan Han
00:10:02
All senses, sight, hearing, smell, taste and touch are involved in flavor perception and they activate the brain circuits involving the dopamine reward system.
Dr. Sanjay Gupta
00:10:11
Over time, we actually evolved to crave certain foods in order to survive.
Professor Dan Han
00:10:18
Health wise, it makes sense that, you know, beyond subjective memories, our species are drawn to flavors associated with high calorie density foods such as sugar and fat. You know, we live in a unique, recorded human history time point where we're actually not only having high calorie density foods, but we're actually having problems because of that.
Dr. Sanjay Gupta
00:10:40
Mm hmm.
Professor Dan Han
00:10:40
You know, and against the principle of too little of anything is no good. Too much of anything. It's no good. It's all about the balance. And the balance can tilt if we're not careful.
Dr. Sanjay Gupta
00:10:51
So if you look at this from an evolutionary perspective, we evolved to enjoy certain foods, foods that would be important to our survival. But at a time when that was the case, it was a very different world. We didn't have ultra processed foods, we didn't have mass manufacturing of foods. We didn't have so many calories so easily available. So therein lies the paradox. On one hand, we got what we always probably wanted as human beings, which was to have unlimited, you know, bountiful food. But on the other hand, we've now seen the perils of that. And that's the inflection point where you're trying to intervene.
Professor Dan Han
00:11:25
Yes. Baked into our DNA is the desire to seek comfort and try to fight. That is also just as irresponsible, in my humble opinion. So don't deny the fact that we want sugary and oily things. I mean, there are delicious from our flavor perception perspective, but at the same time don't create those situations to be so overboard that it's actually hurting us.
Dr. Sanjay Gupta
00:11:55
It's fascinating to sort of realize that whether we enjoy a certain food or we hate it probably has more to do with our other senses, our memories, our histories, than what's really at the end of our fork. In fact, the way we experience food is about more than just the ingredients we use or following a recipe. Contrary to what we've been taught, it actually has a lot more to do with the brain, than our tongue. But once you realize this, you can start to make changes. Professor Han says we can balance our natural desire for high calorie foods with some healthier swaps that will satisfy our brains in the same way. And you don't have to be a scientist, a doctor, or even a professional chef to give it a try.
Professor Dan Han
00:12:38
Try a blue plate if you want people to eat more. Try red plates if you want people to eat less.
Dr. Sanjay Gupta
00:12:44
After the break, Professor Han and Chef Taria share more tricks of the trade you can try in your own kitchen. We've got that coming up in a moment.
Dr. Sanjay Gupta
00:13:01
And now back to Chasing Life and more of my conversation with Professor Dan Han. You know, after talking to Han about the mechanisms of taste and the factors that affect how we perceive food, I did want to learn more about how we can put all of this into action.
Dr. Sanjay Gupta
00:13:16
What would this be like then? Let's say I'm going out to dinner. I want to eat a healthy dinner. Do I eat something that binds to my sweet receptors at a time. Or what would that look like?
Professor Dan Han
00:13:28
Okay, you could actually borrow from color association theories and how they enhance certain sensory perceptions and so on. For an example, how it was used in the United Kingdom National Health Service in 2013 or so. They identified hospital malnutrition as a major problem and switched hospital foods from serving them on a white plate to blue plates. That was it. And that was predicated on experimental psychology, literature on color, association for food delivery and average food consumption for vulnerable patients. On that floor went up from 114 grams to 152 grams as 33% increase. You know, that's a brilliant, simple hack that improved control nutrition delivery for vulnerable patients.
Dr. Sanjay Gupta
00:14:18
Look, that's kind of remarkable. Something as simple as changing the color of the plates ultimately really shifted how these patients perceive their food. And, in this case, even help them recover. As a doctor, that's really exciting. Now, Professor Han says there is still more research to be done, but neurogastronomists also hope to use similar principles to help people with smell and taste challenges as well. Think of people undergoing chemotherapy, older folks, or even those with sinus issues. What if you could experience taste in a new way? Or you could reinvigorate something you've lost by incorporating more color, texture, sound, or smell into the dishes so that your brain essentially processes these flavors in a different way. It's a lot to think about, but it's amazing. You could add extra crunch to a meal that will accentuate the salty flavors. You could add extra color to help your brain register something as sweet or sour. And, these ideas aren't just for people with medical issues.
Professor Dan Han
00:15:19
Now, we could do that for our dinner table, too. You got a picky eater? Simply see if you could get them to eat more. You know, I have a special needs child who is a very, very, very picky eater, and he's nonverbal. And then, you know, him give them something on a blue plate and, you know, hope for the best. It doesn't do the trick 100% of the time, but it does yield those incremental differences. And you could do the exact opposite. You want people to eat less, give them food on a red plate. And these are some of these are immediate delivery hacks, so to say.
Dr. Sanjay Gupta
00:15:56
By the way, you are the topic of discussion and my family dinner last night. I have three teenage girls. You know, I had just been reading, you know, and doing some prep work. And it's fascinating when you start reading about your field and just little things like you just said, like dessert served on a white plate versus a black plate. It's so interesting how our brains are constantly making these inferences about things based on how the food is presented.
Professor Dan Han
00:16:24
Right. And you as a neurosurgeon, you know, you know how all these micro and macro circuits work with reference points and the interplay, almost an orchestra of all these senses coming together for a very, very specific and personalized and subjective memories and what that means for you. The example that I like to use is like eating popcorn. To you it may present, going to the movies with your kids and glazing butter over the salty and umami flavor popcorn. And then having a great time together looking at the big screen and it may bring and spark joy. And all that's associated with that kernel as you anticipate eating that the next time. For me, it may present coughing, dry mouth choking on the kernel. Oh, I ate it while I was coughing, you know, etc.. So it's highly personalized, right? So there's not going to be a universal principle here. We have to be very respectful of our individualized perception and experience.
Dr. Sanjay Gupta
00:17:41
I am curious, when you put all of this together, how do you live your life differently? You sort of said this earlier, but you have a son who's a picky eater. And then when you do hacks like this, you know, you're not saying it's always going to work. But if I were to say, you know, you could have carte blanche in terms of having. The food and setting up the ambiance, the cutlery, the plates, the smell, all of that. Like how much of an influence can neurogastronomers have on the way that we eat?
Professor Dan Han
00:18:10
I'll actually flip that question and ask you, what do you think industry, restaurants, food delivery. industry and food manufacturers, chip manufacturers, potato chips, what do you think they've been doing the last 100 years? That's exactly that.
Dr. Sanjay Gupta
00:18:27
But but but it does seem like they've been appealing to our core desires. Right? The desire as humans for salt and for fat and for sweet. So they've been appealing to something that is well known. But what I'm asking you is like now you're trying to actually in some ways interfere with that process, with all the caveats you mentioned, but still interfere with that process. That seems like a much higher bar than just appealing to our most primal instincts.
Professor Dan Han
00:18:57
I would argue that it's not countering that process. Rather giving into that process. But, with the caveat that we're delivering it in the most balanced way possible. Meaning, instead of just overloading things with salt because we want salt and just overloading things which sugar because we want sugar. Keep the predicate, then we want sugar and we want salt, but deliver it with less salt and less sugar. But have the brain to perceive it as a lot of sugar. And that's right.
Dr. Sanjay Gupta
00:19:42
That's the goal.
Professor Dan Han
00:19:43
That's the trick.
Dr. Sanjay Gupta
00:19:44
But how effective can you be, though? That's my question.
Professor Dan Han
00:19:47
Yeah, we're in our infancy. So the actual effect size of these quote unquote hacks, that's not as established to have high yield to change the planet's culture yet.
Dr. Sanjay Gupta
00:20:02
I realize we're in the infancy, as you say, but in a full manifestation of what this might look like. How would my life or any individual's life change if neurogastronomy was a much bigger part of our lives with the foods that we eat be different? Or would we be taking something that's a supplement to make the foods different?
Professor Dan Han
00:20:24
Oh, foods will look different. So we have evolved to want certain things and then that's going to create demand and then industry is going to provide supply for that demand. And then it individually comes back to us and modifies our behavior. We want more of what we wanted initially. This is what I conceptualize as a flavor economics. So what can we do at the personal and individual level? Don't deny yourself. But, at the same time, come up with neurogastronomic evidence-based tricks so that you could actually enjoy the sugary and enjoy the salty and umami goodness. And if we could do that at the individual level, then the demand changes to the sustainable ingredients. And industrial will just follow. And I have no problem letting professionals who know best how to run industry do exactly that. But not the way they want to feed us, but the way we want to eat.
Dr. Sanjay Gupta
00:21:42
Like I said, this field is about more than counting calories or restricting your diet. This is about better understanding why our brains crave certain foods, whether it's something salty or sweet or creamy, and if we are able to better understand the brain science behind those cravings. Does it mean we may also be able to steer our brains toward foods that are not just good for us, but maybe even good for the planet? That's something big picture that really excites Professor Han and others in the field. Think of a world where you craved a fruit or vegetable that is sustainably sourced the same way you might crave chips just because you hear the same satisfying crunch. That's the future many neurogastronomists would like to create. In the meantime, though, you can make small changes and you don't have to sacrifice flavor to do it. Little things, as you heard from plate color to just preparing meals at home, really taking in all the smells and the aromas, all of that can really help affect our experience with food.
Dr. Sanjay Gupta
00:22:42
And here's a few other hacks from Professor Han to get you started. Tip number one, don't deprive yourself of your favorite flavors, but do try to seek out healthier or more sustainable swaps when you can.
Professor Dan Han
00:22:55
The first step is reusing at home what restaurant industry and food delivery industry has been using to enhance their delivery for the last hundred plus years or so. Which is, you know, trying different plates, lighting cues and all these different established science in psychology so that we could do the same thing with more sustainable ingredients.
Dr. Sanjay Gupta
00:23:25
Tip number two: Make eating healthful foods and vegetables part of your traditions like Thanksgiving. That way, your brain starts getting positive memories to associate with those foods.
Professor Dan Han
00:23:36
So the trick is to come up with ways to associate pleasant and joyous occasions with things that are healthy, that you don't necessarily like to eat right, and vice versa. You know, these are little tricks of the trade to reorganize your habits.
Dr. Sanjay Gupta
00:23:57
Tip number three comes to us from Taria, the chef we heard from at the beginning of the episode.
Taria Camerino
00:24:02
Touch your ingredients. Like, touch them. Get to know them. And yeah, you'll look like a weirdo, you know, you're, like, feeling your rice in the bowl. Smell it. Really. Just get to know all of your ingredients with all of your senses before you even start cooking. And if you're starting out or if it's intimidating, go simple. Don't have 30 ingredients. Four or five that you love. Start there.
Dr. Sanjay Gupta
00:24:32
I got to tell you, I've been really excited to incorporate some of these tips into my own dinner table. I think we're going to get some new colorful plates by Thanksgiving. I've already talked to my wife about this. We're trying to decide if we're going to tell the kids and see if they notice if they'll actually eat less on a red plate or more on a blue plate. It's just fascinating to think about this idea of being more prescriptive in what we serve, but also how we serve it. My biggest takeaway, I think, from the conversation is that even the tiniest change can affect the way you experience your food. So don't be afraid to start small. Your brain and body are probably going to thank you for this. And speaking of Thanksgiving, I recently asked all of you to call in and tell me about your favorite Thanksgiving dishes, how they make you feel. We got some great responses that really did make me hungry....
Caller 1
00:25:26
I haven't met a person who doesn't love my aunt's cranberry sauce. It's a simple recipe, but it's infused in Bangladeshi spices that burst in your mouth and bring you back home.
Caller 2
00:25:36
Growing up Salvadorian American, we always did a typical Salvadoran dish called panes con chumpite, which is essentially like a turkey sandwich with a nutty sauce on top.
Caller 3
00:25:50
My green bean casserole. What I love most about it is the fact that my family begs me to make it and that just make my heart so happy.
Dr. Sanjay Gupta
00:26:07
Thank you so much as always for calling in. I love hearing those messages and I think these messages really do prove Professor Han's point that some of our favorite foods are tied to our fondest memories. And to all of you who celebrate, I wish you a wonderful Thanksgiving. I'm certainly thankful for all of you, the listeners, for supporting this podcast. And with Thanksgiving coming up, I also wanted to let you know that we are taking a short break as well. We're not going to have a new episode in your feeds next week, but we'll be back soon with one of my favorite episodes about how to get a good night's sleep.
00:26:40
After study sleep for more than 20 years. I'm convinced that sleep is one of the most important thing for our survival.
Dr. Sanjay Gupta
00:26:48
That's coming up in just two weeks. Thanks for listening!
Dr. Sanjay Gupta
00:26:51
Chasing Life is a production of CNN's audio. Our podcast is produced by Emily Liu, Grace Walker, Xavier Lopez, Eryn Mathewson and Andrea Cain. Our intern is Amber Alesawy. Haley Thomas is our senior producer and Abbie Fentress-Swanson is our executive producer. Tommy Bazarian is our engineer. And a special thanks to Ben Tinker, Amanda Sealy and Nadia Kounang of CNN Health.