Sweet, Sour, Salty, Bitter, Protein ... and Now Fat

ral writes "The human tongue can taste more than sweet, sour, salty, bitter and protein. Researchers have added fat to that list. Dr. Russell Keast, an exercise and nutrition sciences professor at Deakin University in Melbourne, told Slashfood, 'This makes logical sense. We have sweet to identify carbohydrate/sugars, and umami to identify protein/amino acids, so we could expect a taste to identify the other macronutrient: fat.' In the Deakin study, which appears in the latest issue of the British Journal of Nutrition, Dr. Keast and his team gave a group of 33 people fatty acids found in common foods, mixed in with nonfat milk to disguise the telltale fat texture. All 33 could detect the fatty acids to at least a small degree."

Comments

Show me the receptors

[Mindcontrolled]

Just the fact that people can detect fatty acids in their non-fat milk doesn't imply that there is an actually taste receptor for fat. Could also be the change of texture of the milk or activation of other taste receptors by the fatty acids. I would only call this a specific taste when the associated taste receptor protein is identified.

Re:Show me the receptors

[j00r0m4nc3r]

Just the fact that people can detect fatty acids in their non-fat milk doesn't imply that there is an actually taste receptor for fat. Could also be the change of texture of the milk or activation of other taste receptors by the fatty acids. I would only call this a specific taste when the associated taste receptor protein is identified.

I'll notify the British Journal of Nutrition that their published research is invalid.

Re:Show me the receptors

[pookemon]

"mixed in with nonfat milk to disguise the telltale fat texture"

Perhaps you missed that part of the summary (let alone TFA).

Re:Show me the receptors

[wjousts]

So I've only read the abstract of the paper and they really don't claim that fat is "tasted", just that some people are able to detect it and they link that ability to BMI. Whether they are really tasting or just detecting some other physicochemical effect is still unclear. There are a lot of different senses involved when you put something in your mouth. There is a lot of evidence that suggests that fat is a taste, but so far nobody has presented a receptor for it.

Re:Show me the receptors

[O-Deka-K]

Well, it's well known that people often associate tastes and smells with their most vivid experiences.

Re:Show me the receptors

[HEbGb]

You're right. I'd imagine the fault is not with the original paper, it's in the interpretation of this paper by the popular press. We see this again and again.

Re:Show me the receptors

[PopeRatzo]

sweet, sour, salty, bitter and protein

That's also what she said.

the Calcium taste buds weren't listed

[OlRickDawson]

There is the Calcium(www.dailymail.co.uk) taste buds which were not listed, and I'm sure there have been others discovered.

Re:the Calcium taste buds weren't listed

[BKX]

First, did you actually read the article you linked to? It clearly states that they don't believe that we have an extra calcium sensing taste bud, but that our existing taste buds detect calcium as bitter, and therefore people who are sensitive to bitter (and don't like it) tend not to eat enough calcium as a result.

Second, there are probably a whole bunch of tastes we can detect that we don't list as having special taste buds. Picante* comes up high on the list (and is an important consideration in many cuisines). Umami was a taste that many didn't list until just a few years ago but was always a consideration in Asian cuisine (as is picante). Anyone with half a brain could have told you that humans can detect fat content in food by taste. Just go and try the fat free equivalent of a naturally fatty food. It'll taste like ass, precisely because you're not sensing the fat content. They can try to substitute things in to overcome this limitation like extra sugars or textures that mimic the mouthfeel of fat, but they aren't the same as actual fat.

* (This is the Spanish word for the hot kind of spicy. In English this is sometimes called piquant (from French), but that word can also mean spicy in a more general sense (think Christmas spice), and so I like the Spanish word instead. Hot is also a bad word for picante since it can also refer to temperature, and when talking about food, we need to differentiate somehow.)

Re:the Calcium taste buds weren't listed

[jedidiah]

Picante has also been described as ALL of your tastebuds being forcibly activated at once in a sort of brute force sort of way as if they had been forced open by crowbars.

So Picante is just gastronomic napalm.

Re:the Calcium taste buds weren't listed

[jc42]

I may be mistaken, but I think it is generally considered that spicy or picante does not have a flavor receptor and that the picante experience can be attributed to chemicals that cause irritation in our mouths.

Yeah; you probably are mistaken. ;-) For a long time, there has been a bit of a medical mystery about how hot peppers produce a sensation that feels like major heat damage, but medical tests can't detect any actual tissue damage of any sort. This was answered a few years ago by some researchers who determined that the capsaicin chemical that does the job targets specifically the nerve endings that detect heat, and tricks them into sending a false signal to the brain saying "I'm being burned!"

An interesting aspect to this was verification that capsaicin does target specifically mammalian heat sensors, and doesn't work with birds. Anyone who has pet birds is familiar with this. Seed mixtures intended for birds such as parrots usually contain hot peppers, which the birds like. I like to grow my own hot peppers in pots that I bring in during the winter. I have to protect them from our pet conure and cockatiels, because they'll land and the plants and devastate them. When I decide to pick the ripe ones, the conure especially is right there demanding samples of the harvest, which she devours whole.

Further research is needed on the topic, but the hypothesis is that hot peppers evolved their "hot" chemical explicitly to distinguish between mammals and birds. Pepper seeds have a thin, leathery shell which doesn't survive the long, slow digestive system of most mammals. But birds can't afford to carry food around for long; they have a short, powerful digestive system that extracts just the easily-digested stuff and dumps the rest after only a few hours, because it would take more energy to transport it than it contains. The leathery shells of pepper seeds do survive a bird's digestive process. So the hypothesis is that peppers are specifically encouraging birds as seed-transport agents, and discouraging mammals that would digest the seeds.

There's some sort of biological irony in the fact that hot peppers have been spread from their origin (South America) to the rest of the world by a mammal (us). Of course, we can easily do something that's difficult for other mammals: We can dilute the hot pepper enough that it's just a minor (or not so minor) flavor mixed with other flavors, and not overpowering as it is if you eat the pepper alone.

In any case, to be on topic, we should note that the hotness of hot peppers isn't really a "flavor". It's more a case of our heat sensors being tricked by a chemical produced by plants that are trying to prevent us from eating their fruit and digesting their seeds.

Protein?

[Chris Mattern]

It took me a few moments that by "protein" they actually mean the so-called "fifth flavor" often referred to by the Japanese word umami "savory".

Re:Protein?

[Mindcontrolled]

Glutamate is an amino acid that makes up proteins. The receptor recognizes it in its unbound form, not in the form incorporated in proteins, though.

Re:Protein?

[amRadioHed]

You mean it took you a few minutes to get to the third sentence in the summary where it said just that?

Re:Protein?

[RManning]

That kind of confused me, the umami taste is caused by glutamates which are sometimes found in protein heavy foods but also come from such random places as tomatoes, seaweed or a number of fermented sauces. Protein doesn't really have anything to do with it.

Actually, it does. All those "random places" you list contain protein. Don't mistake protein and meat.

There's something else

[Misanthrope]

What the summary doesn't mention is that the BMIs of the sample group were inversely proportional to their ability to sense fat.

Re:There's something else

[brian0918]

Except of course that most obesity is caused by insulin resistance, which in turn is caused by continual spiking of insulin from increased blood glucose, which in turn is caused by continual consumption of highly-refined carbs. So while fat people certainly eat fatty foods (as does everyone else), the root cause of their obesity is the refined carbs in their diet, not the fat.

Re:There's something else

[spun]

Many flavors are soluble in fat, but not water. When creating low fat versions of high fat dishes, you must always adjust the seasoning to account for this.

Re:There's something else

[jedidiah]

Well, that's just today's obesity which is an effect of the relatively recent demonization of fat.

People ran away from fat and there was sort of a nutritional backlash.

It also didn't help that the inherently unbalanced and politically motivated "new" food pyramid did not account for American eating habits.

Result: "remove fat, replace with refined carbs and no fiber"

Re:There's something else

[RManning]

As someone who has gone from obese to quite trim, I can tell you that in my experience obesity is caused by taking in more energy than you burn, period! I cut the amount of calories i take in, and I lose weight. I add calories, I gain. I was never a carb eater, just a "too much" eater. Of course, carbs are really high calorie, so generally cutting calories mean cutting carbs. But, I'm not convinced the type of food is nearly that important.

That's my long winded way of saying: citation needed. :)

Re:There's something else

[camperdave]

in my experience obesity is caused by taking in more energy than you burn, period!

That's the easy way out. You're never going to sell any diet books like that. You've got to have a "system", and if you can tie it into merchandise, especially consumable merchandise like food, then so much the better.

What about electricity?

[Anonymous Coward]

You know... for when you're testing 9 volt batteries.

Re:What about electricity?

[trentfoley]

I'm sure the poster would have chosen DC had it been an option. AC was the closest possibility.

Re:What about electricity?

[ozbird]

9v battery is for sissies. 12v wall wart is for real men.

"Real men" know that wall warts don't go flat.

Re:Savory

[Wyatt Earp]

Savory is umami.

The Bastard Broadcasting Company had a doc on it

[SmallFurryCreature]

Those scumbags had a documentary on fat in our food and how we as humans have evolved because of it and become very good at eating very fatty food. And they showed it all with constant displays of fat food... succulent beef, silky smooth chocolate, whipped cream, bacon and eggs... I gained ten pounds just watching and at the end ate my remote control.

On the whole, I have to say they got a point. Fat tastes good. Some animals have learned to eat/detect certain muds because they need the minerals in them. Our brain needs fat to fuel itself, so we have learned to tast fat.

Now if you excuse me, I got to devour a liter of icecream... mmm.

A special category of first post for science

[spun]

In any science story, we will more than likely find a special category of 'first post' comment: the 'I'm smarter than teh science-talking-guys!" first post. These posts always feature a blindingly obvious 'criticism' of the science at hand, usually made by someone with no formal training in the field, that any competent scientist will take into account, but many halfway competent science writers will fail to mention. Thus, to the uninformed, the first poster appears insightful. "Wow! Good call, how could those dumb scientists miss that?!?" Uh, yeah, they didn't. I'm just curious, but what is your background in biology and chemistry? Are you educated on this subject, or are you just one of those people who likes to think they know better than those boneheaded scientist-types?

Just in case I haven't made it crystal clear: you have not thought up anything the scientists did not take into account. I guarantee, you have not come up with a cogent criticism of this experiment, and you are not smarter than the fellows performing this experiment. You are not insightful, and your karma whoring question does not add anything of value to the discussion.

Re:A special category of first post for science

[Mindcontrolled]

To satisfy your curiosity - I have a degree in biochemistry. Not in sensory biochemistry, I worked in the field of protein structure while I was still in academia. My criticism is not so much directed at the scientists doing that experiment, but rather on how it is reported here. I didn't even challenge the validity or the design of the experiment, I was just asking a follow-up question. The barrier to establishing a new category of taste simply is the identification of a receptor for it. The sensory system is complex, so the simple fact that fatty acids are detected does not mean there is a taste category associated with it. You might have noticed that my post was in fact not of the "LOLOLOL dumb scientarst idjots" type, I was just asking the question that any life scientist would ask when seeing this headline - "Is there an actual receptor?".

Re:A special category of first post for science

[gtbritishskull]

What amazes me is that you were able to RTFS, then follow the link and RTFA, and then follow the link in that article, while still being able to get first post. Absolutely amazing.

Re:A special category of first post for science

[spun]

Actually, yes. Yes I do.

Re:but why?

[snspdaarf]

Bite down on your tongue. It tastes painful.

Well mod me down, then!

[spun]

Okay, well, ahh, kind of took the wind out of my sails. In my defense, you are probably the first actual knowledgeable Slashdotter to engage in this kind of first-postery.

Re:The Bastard Broadcasting Company had a doc on i

[somersault]

I used to believe all that crap about low fat this low fat that, it's everywhere. I've been eating a lot of fatty foods since last September though and I'm still not fat. I do avoid high GI foods though unless I've just been doing heavy exercise. Ice cream is meant to be a good way to get fat because it combines both high sugar and high fat.

Sweet, bitter, now fat

[ascari]

Relieved to see TFA was about tastebuds: When I saw the title I thought somebody had published the story of my life!

Re:Umami vs. Savory

[canajin56]

Because we used "savory" to mean "pleasing" which describes all kinds of good things. Unless you're European, in which case you mean "savoury" as in the course that follows pudding, usually pickled fish, toasts, or brandied fruits, few-to-none of which are "savory" like you're trying to twist and bastardize the word into meaning. We've not ever referred to glutamates as "savory". If we've ever referred to a specific taste as the "savory" taste, it's been aromatic herbs, not glutamates. PS "savory" comes from French, so funny that you're all anti-Japanese (even implying he lied by saying he "supposedly" discovered the taste receptors) when the word you want to use isn't even ENGLISH ORIGINALLY. Some bastards started using it 800 years ago when they discovered there wasn't a word for it, but the French had one! Heaven forbid we do that again. Nosir, gotta protect the language, NO NEW WORDS.

Re:Umami vs. Savory

[canajin56]

Savory in English MEANS things flavoured with aromatic herbs, which doesn't make for a very good etymology.
Savory in British MEANS for the course of a meal that's served after pudding, which doesn't make for a very good etymology.
In fact, along the first point, there's even a herb specifically called "Savory". Also you have a bizarre definition of "technically equivalent" if you are saying "sweet" technically means "aromatic herbs".

Re:but why?

[somersault]

For some reason even if I initially notice the smell of someone's breath when kissing, it goes away after a second or two. I wouldn't say I have ever tasted another person's tongue, though I have detected hints of chocolate after she apparently only had one malteser in the past 20 minutes or so.

I think you are more likely to taste your own tongue after you try brushing it with some toothpaste to get your tastebuds all confused. I'd say it's likely to just be the taste of your own saliva though rather than your tongue actually having a taste of its own. You could always just try eating it..

Wow this is a strange conversation.

Re:The Bastard Broadcasting Company had a doc on i

[Korin43]

I'm surprised that anyone believes the whole "If you eat fat you'll get fat" thing. How you get fat is pretty simple: You need a certain amount of calories, and if you eat more than that you'll gain weight; if you eat less, you'll lose weight. It's true that some high-fat foods have more calories than low-fat foods (bacon vs salad), but it's not the fat percentage that's making you fat.

I guess it sort of makes sense to think that eating fat would make you until.. at least until you realize that eating salad doesn't turn you into a tree.

Re:The Bastard Broadcasting Company had a doc on i

[eonlabs]

The insulative layer surrounding neurons is made of fat. No fat, you get excitation bleeding (not blood, think short circuits). http://en.wikipedia.org/wiki/Myelin

Re:The Bastard Broadcasting Company had a doc on i

[infaustus]

Energy enters neurons almost exclusively as sugars. In the rare situations when adequate carbohydrates are unavailable, neurons can survive off of ketone bodies from fats elsewhere in the body, but this is a last resort and ketone bodies have poisonous byproducts. In this context, saying "the brain is fueled by carbohydrates" is true and meaningful, saying it runs on fat is mostly false, and saying it runs on ATP is not meaningful and sort of dickish.