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Are There More Than Five Basic Tastes?

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Are There More Than Five Basic Tastes?

Are There More Than Five Basic Tastes?

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GUY RAZ, HOST:

On the show today, ideas about the five senses and how they help us perceive our own version of the world around us. So taste is a sense that's great - right? - it's like the pleasure sense. But is it actually as important as the others? I mean, we could live without it, right?

NICOLE GARNEAU: Hearsay, Guy, hearsay. Taste is the last barrier to you putting something in your mouth that could go in your stomach and poison you.

RAZ: OK, but pretty important.

GARNEAU: Yes.

RAZ: This, by the way, is...

GARNEAU: Dr. Nicole Garneau.

RAZ: And Nicole is a scientist at the Denver Museum of Nature & Science, where she studies taste.

GARNEAU: It is the last line of defense our ancestors, in terms of evolution and survival, used to ensure that they stayed away from things that were going to kill it. And they made sure that they swallowed things they needed like protein and carbohydrates, fats, salt.

RAZ: Taste is not a frivolous science.

GARNEAU: It is not a frivolous sense.

RAZ: OK.

GARNEAU: It should be taken very seriously...

RAZ: All right, yeah, sorry.

GARNEAU: ...And also with a lot of fun (laughter).

RAZ: So just like there are five senses, most scientists believe there are five tastes. And each one plays a very different role in keeping us alive, as Nicole explained on the TED stage.

(SOUNDBITE OF TED TALK)

GARNEAU: We're going to start with the one that we like the least, and that's bitter. We're born not liking bitter, and that's because bitter equals poison in terms of survival. But we can learn to like bitter things once we realize they're not poison, and a great example is caffeine - coffee.

So let's go to the other end of the spectrum. We love sweet because it is the taste of pure energy via simple carbohydrates like sugar. Now similarly we love umami, umami is the savory taste of protein, another thing we need for our bodies to survive. All right, now we're going to talk about a funky one, and that's sour because it can either help us or harm us. So we tend to like weak acids like citric, and that's probably because we've evolved to need to like it so that we get vitamin C. But we do not like strong acids, like that in a car battery, right? That's going to kill us, we're not going to consume that. So the final one is salt. When your body needs salt to maintain fluid levels or other internal processes, we crave it.

All right, so I just laid out for you taste. Taste is pretty logical and pretty straightforward when it comes to survival. I think it's too simple, actually, so I want to throw a wrench in what you think you know about taste. If evolution and survival are so complicated, as we know they are, why would taste be so simple? So I was curious about this, and I asked the question, why five?

(SOUNDBITE OF MUSIC)

RAZ: There could be a sixth taste?

GARNEAU: That could be a sixth, seventh, eighth, so on and so forth. In terms of where the evidence lies, the one that seems to be the closest to really convincing sensory scientists across the world that it exists is fat taste.

RAZ: Fat?

GARNEAU: Fat taste is probably the sixth taste.

(SOUNDBITE OF MUSIC)

RAZ: In just a moment, the hunt for the mysterious sixth taste. Stay with us. Today on the show - ideas about the five senses. I'm Guy Raz and you're listening to the TED Radio Hour from NPR.

(SOUNDBITE OF MUSIC)

RAZ: It's the TED Radio Hour from NPR. I'm Guy Raz, and on the show today - ideas about the five senses. And we were just hearing from Nicole Garneau, who studies taste at the Denver Museum of Nature & Science, where she, like some other scientists in the budding field of taste research, thinks that fat might be the mysterious sixth taste.

GARNEAU: When I say fat, what do you think of?

RAZ: I think of just big pieces of fat off a piece of meat.

GARNEAU: (Laughter).

RAZ: Just you, know, congealed fat from the, you know, the meat that cooked in a pot.

GARNEAU: So this is the problem with taste science, is that it is dependent in a lot of ways on language. And so when I say fat, I'm thinking of the actual molecules, the fatty acids, the good fats - right? - omega-6, omega-3. So the fatty acid that we study is linoleic acid, and it is in meat, nuts, vegetables. It's something that your body needs to eat almost everyday to survive because our bodies can't make it.

RAZ: So what does it taste like?

GARNEAU: It's actually a pretty gross taste. It's like - for me it's kind of like stale popcorn in a bag that got left in your car, maybe with some melted plastic on it.

RAZ: Ew.

GARNEAU: Not tasty, no.

RAZ: No.

(SOUNDBITE OF TED TALK)

GARNEAU: So I'm out to prove that that is the sixth taste. And in order to do that, you have to answer a lot of questions. But the one that's most intriguing to me as a geneticist is this - is there a gene for fat taste? So your ability to taste is wrapped up in tens of thousands of years of your family history through evolution, and all of that evolution is written today right now, right in you, in your DNA.

So if you think about your DNA like a cookbook for your body, then like any good cookbook, your DNA cookbook has genes. These are recipes, right? So recipes or genes, same thing, they are the instructions telling your body how to make something it needs to survive. And to tie it back to taste, my goal is to find the gene or recipe for fat taste. So I'm going to need thousands of people to come into my lab to do taste tests, to answer questions about themselves, and to do a cheek swab kind of like the "CSI" shows, except for we're going to use it to study taste genes.

(SOUNDBITE OF MUSIC)

RAZ: Nicole and other scientists are working on this right now, and they've already begun to prove that fat is a taste we can detect.

GARNEAU: And we have a paper published that shows as we increase the amount of fat in a taste solution, people can actually tell us that it's been increased, even when we do it in a double blind study and don't tell them what's in it. But there's a lot of other work that needs to be done, and I am fully supportive of it, and I think that it's going to show that fat taste is real.

RAZ: How would it change our understanding of taste if fat is recognized as a sixth taste?

GARNEAU: Taste research is being done to understand so much in terms of nutrition. And so the more we can understand about how our bodies work - and a fat is part of that, fat taste is part of that - then I think the smarter we can be about, well, how do you create recipes that are healthy that somebody actually wants to eat?

Or how do we make drugs that, you know, potentially have - like, a lot of drugs are bitter, so how can you make drugs that are bitter offset that so that, like, kids can take it and they can get better if they need that drug? And so if that's just one more piece of the equation, it's not an end all to solving like a problem around obesity by any means, but it is something that we need to consider in terms of how our bodies work in modern day, you know, modern day life, which is - modern day life is not how our bodies evolve to live.

RAZ: I have to assume that, like, over time, our taste evolves pretty radically. Like, if you were to take Neolithic human - right? - and drop them into, you know, 21st century Earth, they would freak out because they would taste things and it would just be so crazy to them, right?

GARNEAU: So taste preference is innate. So we are born liking sweet. We are born not liking bitter. That's in all of our DNA for the most part, unlike smells. Like, there's no smell that everyone loves, or there's no smell that everyone hates across the world, but taste we really have this.

So if you dropped somebody from Neolithic times into our time, they would probably still like sweet and probably still not like bitter. The thing that I love around taste and flavor research in this day and age is how much we are now seeing this cultural mixing of the foods that we eat no matter where you are in the world.

And so the ideas behind it is how, as humans, do we think about what we have innate preferences for, but then be food adventurous enough to survive in a world that's actually much more diverse than the little world that we live in?

(SOUNDBITE OF MUSIC)

RAZ: Nicole Garneau is a curator at the Denver Museum of Nature & Science. You can see her full talk at ted.npr.org. Today on the show - ideas about the five senses.

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