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Smell And Taste movie

find out how our twin senses keep us alive; every wondered why some people like the taste of burning hot chills. Or strange foods like mouldy cheese. Or why the smell of rotting flesh makes you gag. Tonight we're going to find out how our twin senses of smell and taste keep us alive. We'll be looking at how when it comes to food. Humans have a high-risk strategy. We'll put almost anything in our mouths. Relying on our sense of taste to stop us from poisoning ourselves. We'll be finding out why something's smell so good to us. And others are totally disgusting. And we'll be taking a whiff of the worlds worst smell. Forty foot under the sea in the Bahamas. We're here to do taste test. How does the human sense of taste compare to other animals? What will one of the world's most ferocious carnivores make of something we love to eat? Sharks have a reputation for being the garbage cans of the sea. But how do they measure up to us? A fish head swallowed straight down. Just what you'd expect. But now we're going to give them something they don't normally come across, a chicken.





 
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What will they make of a favorite human food? Look ones taken the chicken, but there he spat it out. In fact most species of sharks are actually picky eaters. They'll turn down a perfectly edible piece of meat, and don't even bother offering them fruit and veg. When it comes to eating anything and everything the human sense of taste wins hands down. Sharks aren't the ultimate garbage cans we are. Some of the things we eat are truly bizarre. There's sweat dripping off it. There's mould growing through it. But these people love Stilton. It's lovely, it creamy. It's absolutely Delicious. It's incredibly beautiful taste. Now meet the Paydan lovers. Victor, Fum, Richard and Ying. In the west we call these thousand year old eggs, it's a raw duck egg that's been buried in ash, tea, lime and salt, for about a 100 days. The really adventurous will even try these caterpillars. Don't with that. So here goes. We'll try just about anything, but we rely on our sense of taste to tell us what we should actually swallow. Youngsters reject quite a lot of food. They tend to turn down anything remotely bitter. We start off disliking bitter tastes because our sense of taste is trying to steer us clear of danger. In nature poisonous plants often taste bitter. So that's why children are reluctant to eat their greens. And sour tastes aren't very popular either. A sour taste can mean something has gone off or is dangerously unripe. So few children like sour tasting citrus fruits. But we adore the tastes that give us what we need. We like salt because we need it to replace salt loss through sweat. And above all we love sweet foods. Because sugar means energy. But if you think children have a sweet tooth, their craving for sugar is nothing compared to some animals like the humming bird. At the South Eastern Arizona Bird Observatory they feed humming birds with sugar water. Just because humming birds don't have teeth doesn't stop them from having a sugar craving. They're among the most sugar hungry creatures on earth. So just how much do hummers love their sugar? Will they go for anything that looks vaguely like their feeding station? Humming birds are passionate about sugar water, because they get most of the energy they need to survive from sugars. Humming bird consume half their weight in sugar every day. And even though we humans like sweet things we can't match that. It would be like us eating a thousand bars of chocolate. At the other extreme there are animals with absolutely no interest in sweet things. Cats just eat meat. They get almost all of their energy from the fat and protein. So their tongues don't even register sweet tastes. So like all animals the tastes we crave are determined by what we need. In our case sweet, and salty foods. But sour and bitter things might be poisonous. So we need to tell these different tastes a part almost instantly, and we're equipped with tongues that can do just that. I don't like it. Our saliva dissolves morsels of food, releasing chemicals, which travel down to the taste buds, which are buried in the surface of the tongue. When bitter or sweet chemicals land on the surface of taste sensing cells, a bitter or a sweet signal is sent to the brain. Salty and sour chemicals are even smaller. They pass right through the walls of the taste sensing cells. Once inside they trigger a salty or a sour signal to the brain. But the same food can taste very different to different people. That's because some people are far more sensitive to tastes than others. Which limits how far each of us can go with strong tasting foods? There's a simple way to find out what you're made of. And these people adore them. My records 15. These is nothing in compare But tasting these foods for the first time can be a very different story. Let's do an experiment and turn the tables on them. What will the Paydan lovers make of the taste of mature stilton? Even the look of it worries them. And what would the stilton lovers make of a fermented duck egg? Time to get tasting. If I took another bite of that l would absolutely throw up. It just tastes like something gone off. So like something rotting? Ah yes. As far as I'm concerned the nicest bit of this is the plate. Did they find it utterly disgusting? Absolutely. We all have a remarkable ability to acquire a taste for things even if we hate them at first. And that adventurous sense of taste gives us humans an amazing advantage. Just imagine if we simply didn't take to new tastes. What if we were like the pickiest animal on the planet? We've come to San Diego zoo to meet an animal that has a taste for just one kind of food. Eucalyptus. They only eat eucalyptus, only certain species of eucalyptus, only certain leaves on the end of the branches, and it has to be fresh. And these animals will only eat a few kinds of eucalyptus. Probably a little over 500 species of eucalyptus. They will eat about 3 dozen out of those. For breakfast it eucalyptus, for lunch its eucalyptus. For dinner its eucalyptus again. To us it's an incredible boring diet. But it suits the koala just fine. Koala it's an old aboriginal word which means no drink. They don't even have to leave the trees to get water. They get 90% of their moisture from the gum leaves that they eat. The koalas get the eucalyptus trees to themselves. Because few other animals can digest the leaves. But they pay a high price for refusing to eat anything else. They must rely on big stands of eucalyptus trees of just the right kind. If they're cut down these guys have nothing to eat. The koala is now threatened with extinction all because it refuses to try new tastes. It couldn't be more different to us. We're one of the world's greatest omnivores. We can survive across the globe, because where ever we go we can always find something we like to eat. Here in Mexico City, there's a restaurant where if it flies, crawls, slithers, or walks it's on the menu. I'll have those. That looks interesting. Sauteed grasshoppers flash fried caterpillars and boiled cacti; it's all on offer. There are representatives from all of the kingdoms here. Plants, animals and fungal. There are amphibians like frogs with green sauce with rice. And Reptiles like iguana. Whether we're vegetarians or meat eaters, there's one thing about our sense of taste that we all have in common. We're willing to try new things we've never tasted before. We all live in different taste worlds. And we're going to find out a little bit about the taste world you live in. By painting your tongue with this blue food coloring. With this dye the structures that hold the taste buds will stand out as pale dots against the dark background. The more dots the more sensitive to taste. The most sensitive are called super tasters. And they can have 100 times more taste buds than other people. So is this man a super taster? Ok, I can look at your tongue, you're a super taster. And let me ask you some questions about what you like. Do you like alcohol? Do you like her bitter vegetables? Well we know a little bit about why that is. You don't like alcohol because it's both bitter and burns your tongue more than it would that of a non taster. And you don't like bitter vegetables because super tasters are particularly responsive too bitter. About 1 in 4 people are super tasters. With their sensitive tongues they tend to be much pickier about what we eat. Because things do genuinely taste different too them. So look at how differently a non taster and then a super taster react to a bitter chemical. So each of us has a built in limit to how strong tasting we like our food. As we grow up we learn to become more and more adventurous. But it takes time. As we try things we gradually discover that even though some foods taste bitter or sour, they're not actually poisonous. Gradually we start to acquire a taste for all sorts of things that we once found disgusting. It's an astonishing transformation. We don't just tolerate things that we hated as children; we end up really loving them. As adults we override our childhood reaction that bitter and sour are bad. It means that we can relish virtually anything. But for each of us there's one ultimate limit. We've all done it. If you eat something that makes you sick, that puts you off that food sometimes for life. Our reaction to foods that make us ill is a basic biological defense mechanism and the effects can be extremely powerful. This footage of wolves eating a dead sheep was filmed in the 1980's by a team of American scientists. It's a startling experiment to test how sheep can be protected from attack by wolves. The scientists put a pill containing a mild poison in to a piece of mutton wrapped in sheep hide. Within half an hour of eating the bait the wolves start to vomit. Several days later and a sheep is put in to the pen with the wolves. After just one nip at the sheep the wolves back off. For several months these predators will now be turned off one of their favorite meals. It made them sick before and they don't want to make the same mistake again. Just like the wolves when we eat a strong tasting and then we're sick within a few hours, something remarkable happens. The sight and the smell of the plate is enough to make me feel really very sick l actually feel quite uncomfortable and not particularly secure, sort of her at the prospect of being close up to it. A taste can be completely transformed so a food we once liked now triggers deep feelings of disgust. I just cannot touch it. It disgusts me. It makes me feel absolutely sick just thinking about it. My brother, sister and I were presented with a plate of lentils each. And that was all we were getting. I wanted to try some authentic her crispy Chinese duck. We'd drunk quite a lot of different drinks as young men do. And finally I got ordered a half-pint of this stuff. I had a couple of fork full's and then I was allowed to leave the table to be sick. That night I had the most horrendous case of food poisoning. And after a couple of sips, felt really nausea's. I had to make a swift exit for the outside. Our brain fuses the memory of the food and being sick. So even getting close to it is now hard work. We're really adventurous with our sense of taste. But when we do come across something poisonous we're programmed to steer clear of it. My stomach is churning. And I'm quite pleased that I haven't had much to eat today, so far. It's a really, it's really horrible. Our sense of taste has evolved to guide us to what we need where ever we go. It lets us enjoy a fabulous range of foods, limited only by the sensitivities we're born with, and the occasional dish that poisons us. It takes us right to the edge of what's safe to eat. And there's one food above all others that shows just how far we're willing to push those limits. We've come to a chili-eating completion in the American Mid west, to find out just how far the human sense of taste can go. Keeping watch in the audience is Professor Paul Rozin who's spent years studying why we keep coming back for the burn. He's a record holder right there. What's your record? 19, going down today. You're going down baby. Alright you guys ready? Go. The burn of the chili starts to kick in the moment you take a bite. A chemical called capsysin fires off the pain receptors in the tongue. So your tongue feels like its on fire, and your body thinks it's suddenly way too hot. Its panic stations. In an effort to cool down, blood flow to the skin suddenly increases. Turning your face bright red. Your eyes go blood shot and you start to drip with sweat as your poor body desperately tries to deal with the burning hot chili. And despite that entire people love it, and keep coming back for more, again, and again and again and again. The winners eat a staggering 24 chilies. Some of these people actually seem to be enjoying the pain. Everyone does things in every culture that are painful or innately unpleasant. A roller coaster ride is an example. Her chili pepper eating your mouth is saying, get this out of here this is harmful Professor Rozin believes that eating chill peppers is a sort of masochistic adrenaline sport. It a thrill to push your body to confront the pain. Your body is saying get out of here. On a roller coaster or with a hot pepper. But you have to know it's really safe. Because otherwise you will feel her upset. Like if you were really falling down a cliff, instead of on a roller coaster you wouldn't enjoy it. And if you thought your mouth was going to peel off after eating a hot pepper you wouldn't enjoy it either. Even though chilies can be painful we can learn to love them because they don't do any lasting harm. And we get great pleasure from pushing ourselves right to the limit of what's bad for us. What's interesting is that people if you ask people what's the hottest one they like? It's the one just below the one that they can't bear because it's too painful. So they are pushing the limits. So the ability to stuff burning hot chilies into our mouths is a powerful demonstration that we poise an adventurous sense of taste. But what's remarkable about our sense of taste isn't just our ability to eat extreme foods. It's also the sheer range of what we eat - and the reason for that - actually has little to do with our taste buds. It turns out that a lot of what we think of, as taste actually has nothing to do with our tongue. Professor Linda Bartoshuk has a clever trick to show how much of a foods flavor is actually picked up by the nose. I've got a substance and what I'm going to do is have you close your eyes so you don't see what it is and hold your nose. I'm going to put something in your mouth. And here it is. Now close your mouth and what you want to do is tell me what you perceive? Just a little bit of a, can't taste it at all. But a burning sensation on my tongue. Ok. That's all I can get. Now when you let go of your nose you can tell me what it is. Let go of your nose. Ok. Ha wow, cinnamon. Exactly. It's hot, but somewhat like flower. Chalky and sort of powdery. Some kind of powder. Oh it's chalky and hot. It doesn't taste like anything. Cinnamon. Wow that's cinnamon. Oh cinnamon. Oh it's cinnamon. Without their noses even these bright young students can't recognize one of the most common spices in the world. Oh that's pretty good. But our sense of smell does far more than tell us about food. In the second half of the program we're going to unravel the secrets of our sense of smell. Why something perfectly harmless can smell so bad to us that it makes us physically sick. We'll be uncovering the biological reasons why we respond so strongly to bad smells. When compared to some animals we have a very poor sense of smell. Surely nothing can beat the delicate scent of blossom on a spring morning. Well actually there is something. The smells that really get up our noises aren't the nice flowery scents, but the really unpleasant ones like rotting manure. So to understand what gets our sense of smell going we've need to get head for all the nastier smells out there. To start our search for stinks we've come to New Mexico, for a show down with the smelliest animal in the West. It's the skunk. We're going to test whether it's smell is as bad as it's cracked up to be. With the help of Jerry Dragoo who rescues skunks nesting under people's houses. A lot of people don't like them living under their house. But they don't necessarily want them killed either. So that's where we come in. At his home outside Albercurky Jerry's got all sorts of skunks waiting to be returned to the wild. This really brave volunteer has agreed to get covered in skunk spray. The camera crew isn't taking any chances. Yeah if you get the spray on your clothes you usually have to throw them away. Anyone trying to wrangle them back into the travel cage - runs a high risk of being skunked. There he is Argh. Skunk spray contains chemicals like the ones that give garlic its eye watering burn. And rotting eggs their sulphurous stench. The combination is a powerful repellent. Jerry got him. Now bring him over here in to the cage, and drop him right in. Yeah, look at that he's, phew. There we go - great. Thanks for that demonstration. If you see a skink you're expecting to smell something awful. But will a man drenched in skunk spray, we can test what people's genuine reactions are merely to the smell. So skunk definitely smells bad. But it's not totally unbearable. It's not a bad smell from a distance actually. Skunk is ok down wind. It doesn't bother me. Its I mean I would buy it as a cologne. As long as I keep moving. I want to sit in it, you know I think people exaggerate more when they smell, they go Argh skunk, oh. Yeah they make a big thing out of it. It's not that bad. It's not the worst smell in the world. Itís not. So if we're after the bad smells with the most gut wrenching effects on us there must be something worse than a skunk? At the Monell Chemical Senses Centre scientists are working on something far, far nastier. They've spent the last 5 years deliberately trying to create the worst smell on Earth. A smell so awful it could be used for crowd control. Pam Dalton is in charge of the project. How does a reaction to a mal odor develop? What makes a bad odor bad? Is it something experiences you've had in the presents of that odor? Is it something that the odor tells you about its source? Pam and her team wanted to see whether they could create something totally harmless - that smelled so bad, that everyone on the planet would find it utterly revolting. The first step was to find out what people reckoned were the nastiest smells? Not too keen on sulphur - I don't like the smell of that, it's quite, and in chemistry lab that was really not me. There were some swamps I played in as a kid, there were some algae rotting in. Certain types of vomit. Saliva, spit. Itís probably going in to the toilets after he's been in there would be my guess. Dead body smell. Her it never goes away. You know that that smell never go away. I've encountered that several times. He's a cop, just so you know. Freeze... Everyone tends to find the smell of things like vomit, excrement and decomposing bodies, deeply unpleasant. Oh not good whatever it is. But it's only a few bad stinks that really get up our noses. Fundamentally were not designed to be very sensitive to smells. Smell was the first sense our animal ancestors developed. But as we evolved in to humans our sense of smell got worst. For a start our noses are too high off the ground. The best sniffers keep their noses low. Because smells sink down through the air forming an invisible fog just above the ground. As well as being too high off the ground compared to some animals our noses aren't very sensitive. Yet our noses work in the same way as dogs. The main difference is just the size of the snout. Dogs have around 220 million receptors for smell; we have a mere 10 million. Bloodhounds can track people days after they've walked by. They can smell the minute traces of body scent which have seeped through the soles of the shoes and lodged on the ground. For us to smell as well as a dog can, we'd need to have a muzzle as large as theirs. But even with our limited sense of smell, bad odors are capable of giving us a real jolt. We've come to Africa to sample a stench which more than any other has the ability to evoke the most stomach reactions in us. Flesh that has been left rotting in the African sun produces a really awful smell. Spotted hyenas are one of the worlds must impressive carrion eaters. They have a fantastic sense of smell and they're not put off by the smell of a rotting carcass that we'd find so disgusting. In fact it's crucial for their survival that they like it. Yeah in fact I've seen these guys follow her smell up to shove, 20, 30 kilometers, you know. Her, this is like a fillet steak for hyena. You can see it's not like they're just her are eating it because they have too. They're eating it because they want too. The reek of rotting flesh is caused by sulphur containing chemicals released as bacteria breakdown, protein and fat in the meat. By the time it smells off, rotting meat contains such high levels of bacteria that eating it could be fatal. So we find the smell disgusting, to stop us putting rotting flesh anywhere near our mouths. Our sense of smell is warning us of danger. Ooh. Just take a big deep, the smell doesn't bother hyenas because rotting flesh isn't dangerous for them. They've evolved to be scavengers so they have an immune system that can deal with deadly microbes in rotting meat that would kill a human. I mean there have even been cases of wild hyena eating Anthrax, so I mean, Hyenas can actually cope with meat covered in anthrax spores? They've got cast iron stomachs. So we find smells like rotting flesh unpleasant to warn us off. And our noses are actually more sensitive to these bad smells than they are to most pleasant ones. All smells nice or nasty are made of tiny molecules floating in the air. The sulphur compounds, which are the main ingredient of most bad smells, are lighter faster moving molecules. So they have no trouble reaching our smell sensors, which are tucked away in a layer of mucus, right at the back of the nasal cavity. Even if there's just a faint trace of a bad smell, some of the molecules will reach the smell sensing nerve cells, which send their signals to the brain. So because of the design of our noses, we can detect most bad smells at much lower concentrations than pleasant ones. Despite having a puny sense of smell compared to most animals we're particularly sensitive to bad odors. So you might think that creating a smell that everyone in the world finds totally unbearable wouldn't be that difficult. But it turns out that it is. Pam Dolton has found that people react to bad smells in surprisingly different ways. Even the stanch of human faces, or as they politely call it bathroom mall odor. Brace yourself. Here you go. But bathroom mall odor gets a very mixed reaction. We found that it wasn't equally repellent to everyone. From the pool ring? Amazingly, some people just aren't too bothered by a smell others find totally unbearable. Why do we react so differently to the same bad smell? It's not the worst. It's because as we grow up our responses to smells develop gradually. When we're tiny bad smells don't seem to give us too much of a problem. Babies hardly notice the stench of their dirty nappy. But slowly we're influenced by our parents telling us that pooh, is nasty stuff. And our feelings about the smell gradually get stronger. We all tend to find some smells unpleasant. Because they warn us of danger. But how strongly we react is all a matter of personal experience. At the University of California they're studying how we each develop powerful reactions to certain smells. Ok Nigel actually we're looking at your brain now as we speak and your brain looks just fine. I'm glad I've got a good-looking brain. Noam Sobel and his team are using an MRl scanner to see what happens in my brain. We'll be starting up our machine her right now. When we smell something the nerve signals from the nose travel to 2 different areas of the brain. The signals travel up to the frontal lobe, which works out what the smell is. But they also get sent to a set of structures called the limbic system. The part of the brain where we store memories of any intense emotions we've had smelling that smell. So the smell triggers a strong feeling based on our previous experiences. Fear is one type of response that we see here. Disgust is of course another type of response that we commonly see here to odors. And we can all be her quite familiar with that. That is obnoxious. Smells make us feel good or bad according to our own personal experiences of that smell, whether nice or nasty. That's a nice one. It reminds me of chasing butterflies in flower filled meadows in the summer. Particular smells can trigger amazingly specific memories, which effect how we feel about that smell. I was invited to a garden party at Buckingham place. I took my mother along as my guest. And as we walked in to the gardens, the smell of that cut grass took me back to when I was about 5 years old. A smell most of us would rate as mildly pleasant has become the loveliest thing in the world. I remember seeing my mother through the eyes of a 5 year old, and of cause to me she was beautiful - he looked like a princess to me. A perfume intended to bring pleasure, can be tinged with feelings of sadness. The last time I smelt this out of nowhere l had this scene as me as a little kid. A big fairground, her flashing lights everywhere. I remember everything being really high up. The strange thing is I didn't even know I had that memory until the scent came along and there I was kind of her to drop in to this little world all of a sudden.
 
We're going to unravel the secrets of our sense of smell
We're going to unravel the secrets of our sense of smell
  Every wondered why some people like the taste of burning hot chills
Every wondered why some people like the taste of burning hot chills
 
Personal experience can dramatically alter how we respond to smells. So the team at Monell found that different people often had slightly different reactions to bad smells. But there was one stench that produced an amazing range of responses. What was that stench? To most of us it's pretty unpleasant. Ooh. It's not a very pleasant smell Vomit the chemical that gives vomit its arid punch is called butyric acid. My goodness gracious me. That's absolutely horrible. That's dreadful I don't know but butyric acid isn't just found in vomit. Yes it's some sort of cheese. Stale cheese. So the smell isn't that bad if the first thing that comes into your head is something you like. Oh Parmesan. We're all born with mild aversions to some smells to guard us from danger. But as we grow up our reactions are shaped by what actually happens too us. For each of us some bad smells really kick through and others, we end up almost liking. So for the Monell team creating a smell no one can bare has been quite a challenge.
 
Dogs have around 220 million receptors for smell; we have a mere 10 million
Dogs have around 220 million receptors for smell; we have a mere 10 million
  We rely on our sense of taste to tell us what we should actually swallow
We rely on our sense of taste to tell us what we should actually swallow
 
They had to find a way to trigger everyone's most awful memories. Their brew contains a mix of highly concentrated stinks. Cadavorine the smell of rotting flesh dead bodies. The smell of a bathroom mall odor. Their exact recipe is a secret. But they had to get precisely the right amounts of each ingredient to make sure they all come through in the mix. The smell of her vomit, her butyric acid. Which will be the smell of vomit? They call their secret formula stench soup so is this really the most potent combination of bad smells ever created? It's time to put it to the test. A brave group of volunteers have agreed to get a nose full of it. Well first I'm just going to apply a few electrodes to your skin. The scientists aren't taking any chances. Even though this is an airtight room, the smell is so powerful that they will only let people sniff it from inside a suction hood, to make absolutely sure none of the stench escapes into the rest of the building. Ok. Everything seems to be good here. Now it looks as though you are ready to be exposed to the world's worst odor.
 
All smells nice or nasty are made of tiny molecules floating in the air
All smells nice or nasty are made of tiny molecules floating in the air
  The same food can taste very different to different people; that's because some people are far more sensitive to tastes than others
The same food can taste very different to different people; that's because some people are far more sensitive to tastes than others
 
And I'm ready to leave the room. The stench soup will be sucked up from this bottle directly into the nostrils of the volunteer. In a few seconds he's going to experience what Monell claim is the worst smell in the world. When the smell hits - it sends the heart starts racing, and the body starts to sweat. I'm feeling... But how did the other volunteers find it? That was the worst smell I've ever smelled. I like throwing up it was so bad. When the smell came through it was a pretty sudden change kind of get a little gag reflex there. If you were in an area that was filled with that odor would you be able to stay there very long? I don't think so. So perhaps Monell's incredible stench could control a rowdy crowd. Anyone in their right mind wouldn't hang around long enough to get a 2nd whiff of it. Compared to many animals our sense of smell is puny. But when it comes to truly bad smells, even a tiny whiff can knock us to our knees. Compared to all that even a skunk smells sweet.