Australian researchers say fat is 'sixth taste'

March 8, 2010

It's a theory set to confirm why humans are so fond of fatty foods such as chips and chocolate cake: in addition to the five tastes already identified lurks another detectable by the palate -- fat.

"We know that the human can detect five tastes -- sweet, salty, sour, bitter and umami (a savoury, protein-rich contained in foods such as soy sauce and chicken stock)," Russell Keast, from Deakin University, said Monday.

"Through our study we can conclude that humans have a sixth taste -- ."

Researchers tested 30 people's ability to taste a range of fatty acids in otherwise plain solutions and found that all were able to determine the taste -- though some required higher concentrations than others.

They then developed a screening test to see how sensitive people were to the taste and found that, of the 50 people tested, their ability to detect fat was linked to their weight -- a finding which could help counter .

"We found that the people who were sensitive to fat, who could taste very low concentrations, actually consumed less fat than the people who were insensitive," Keast told AFP.

"We also found that they had lower BMIs (Body Mass Indexes)."

Keast said the research, conducted in collaboration with the University of Adelaide, New Zealand's Massey University and Australian science body CSIRO, suggested that the taste of fat could trigger a mechanism in the body.

"We all like eating fatty foods. What we speculate is (that) the mechanism is to do with stopping eating. Your body is able to tell you you've had enough and stop," he explained.

"And if you are insensitive to it, you're not getting that feedback."

With fats easily accessible and commonly consumed, it was possible that people may become desensitised to the taste of fat, leaving some more prone to overindulging in calorie-rich foods, he added.

The results, published in the , have not definitively classified fat as a taste but Keast says the evidence is strong and mounting.

For something to be classified as a taste there needed to be proven receptor mechanisms on taste cells in the mouth, he said.

"We have what... we will call possible candidate receptors for fat on taste receptor cells," he said.

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Mar 08, 2010
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not rated yet Mar 08, 2010
My personal experience with eating fat is that I become more sensitive to tasting it when I eat less fat with that effect taking several days to a week to become noticible. If one remembers McDonald's "McLean burger" a couple of decades ago. I tried them, got 'used' to them, and when returning to eat regular burger found it tasted like it had too much fat.
not rated yet Mar 08, 2010
P.S. to "McLean burger" comment. I did not loss weight during the time period eating "McLean burger." As a result, I would say it is not how much one weighs. it is how much fat one eats that determines ability to taste fat.
Mar 08, 2010
This comment has been removed by a moderator.
not rated yet Mar 09, 2010
Yeah, I thought umami was the 6th. I knew one was missing from there. I don't know, you can feel spicy in your eyes and nose :P

edit: I suppose you can feel sour and bitter and sweet and salty in your eyes n nose too...hahaha. more credit to it :) sure you could feel olive oil too...but I'm not putting olive oil in my eyes or nose. The eyes thing seems a bad idea. Like, instincts telling me not to do it :P

Anyway, are there really umami taste receptors? Are they like past the sour or salty area? I think when I taste concentrated umami its located around the back of my gums. Like wine...well, the fat receptors they're looking into, I wonder if it has more the ability to sense the texture of something. Fat being the other liquid we need to consume to would be good to have a way to sense it. Y'all know what i'm talking about, you get that velvety, slick feeling along your tongue and in your mouth when you chug that olive oil? 7th taste 7 colors 7 days :p
not rated yet Mar 09, 2010
Good point AJW. People who are obese on average eat higher-fat diets. So they would on average be desensitized to it.
It works with many tastes, like sugar and salt. If you eat less salt or sugar, you're more sensitive to them.
not rated yet Mar 09, 2010
Where did these official flavors come from? When i first saw '5 flavors' i thought of the five flavors in Chinese Medicine: Sour, Bitter, Sweeet, Spicy, and Salty. Each corrosponds to one of the five Yin organs in their classification scheme. The belief is that each of these flavors affects health in different ways. What would actually be necessary to constitute a 'flavor'? Who decides this? why dont we add bad flavors too? rancid, burnt, etc.

In china, there is also a dish from Sichuan called Ma La Tang, which means Numbing Spicy Scalding. it is a kind of soup. they use Ma Jiao, a kind of pepper that numbs. Would taht be a flavor too? Is there a similar classification for textures?

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