Mouth May Have a 6th Sense for Fatty Foods

[Dodger]

http://my.webmd.com/content/article/114/111080.htm

Fat Sensors on the Tongue May Give Some People a Taste for Fat
By Jennifer Warner (http://my.webmd.com/content/Biography/7/1756_54621.htm)
WebMD Medical News
Reviewed By Louise Chang, MD (http://my.webmd.com/content/Biography/8/109805.htm)

Oct. 20, 2005 - Move over sweet tooth, here comes the fat tongue.

A new study suggests that some people may have a sixth sense when it comes to tasting fatty foods, which may explain why some folks have a harder time resisting fried foods and other fatty treats.

The results show that rats and mice have a special sensor on the tongue that detects and tastes fat in addition to other known taste sensors, such as sweet, salt, sour, and bitter.

Researchers say that until recently it was thought that mammals could only sense fat in the mouth through clues provided by its scent and texture. But the possibility of an additional taste sensor for fat has been suggested because many animals display a spontaneous attraction for fats.

A Fat Taste Bud?

In the study, published in the Journal of Clinical Investigation, researchers identified a protein called CD36 (also known as fatty acid transporter, FAT) as the first candidate for the fat sensor in mice and rats.

First, researchers found that the protein is located alongside taste buds on the tongue, which suggests that it may play a related role.

Second, experiments showed that in mice missing the gene that makes CD36, there was elimination of the natural preference for fatty foods as compared with a normal group of mice. Mice without the gene did not differentiate between a fatty solution and a nonfatty one, while those with the gene preferred the fatty one.

Finally, stimulating CD36 proteins on the tongue with the fatty acids found in fats triggered increases in stomach secretions used to digest fats. This was evident in a test comparing normal mice with mice missing the CD36 gene.

Researchers say the results suggest that an alteration in this fat perception system may play a role in how much fatty food people eat and the risk of obesity.

SOURCES: Laugerette, F. Journal of Clinical Investigation, Oct. 20, 2005, online advance edition, vol 115. News release, Journal of Clinical Investigation.

[Duparc]

Surely it is our sweet-tooth that causes so many of us to become obese rather than the taste for fat?

Without seeking to sabotage this thread possibly some readers may like to hear this anecdotal tale of pups and their natural diet. Earlier this year my Norfolk terrier bitch (which is fed on raw scraps of meat, fat, and bone) gave birth to three healthy pups. At the 3 week stage, while still suckling from their mother, my wife placed a portion of fatty-meat about a foot from the pups while they were on the teat. Amazingly, they each stopped suckling from their mother and made their way towards the meat which they rapidly devoured! At the five week stage my wife placed a large marrow bone for the adult male. The bone was as large as the three pups put together. Before the male could get to the bone the three pups surrounded it and started chewing at it! Their mother kept the male at bay!

Clearly, we seem to have something that attracts us to our natural diet and which, in today's society, the astute food manufacturers have sourced to make their non-nutritional products appetizing.

[ysabella]

I should have thought it was obvious that fat carries flavors; the French and most TV chefs seem to think so. And I think the textural component of fat is noteworthy as well.

Being pregnant has increased my appetite for animal fats - butterfat and fatty meats - so maybe my tongue-proteins have fired up more or something. :p

[TarHeel]

I've lost over 30 pounds indulging my fat tooth. Fat is what makes foods taste good to me.

My sweet tooth has never been the problem.

[kebaldwin]

Tongue has built-in taste for fatty food
Reuters
NEW YORK - By Amy Norton

NEW YORK (Reuters Health) - The tongue may indeed have a taste for cheesecake, french fries and butter cookies, according to study published Tuesday.

In experiments with rodents, French scientists identified a receptor on the tongue that appears to detect dietary fat. This counters the traditional view that the taste buds pick up only five basic flavors: sweet, sour, salty, bitter and "umami," -- a flavor associated with the food additive monosodium glutamate (MSG).

The fact that the tongue harbors receptors for fatty acids could shed new light on appetite control and obesity, according to the researchers, led by Philippe Besnard of the University of Bourgogne.

They report their findings in the November issue of the Journal of Clinical Investigation.

Scientists have speculated that the tongue may have a receptor designed to detect fat, but this study is the first to pinpoint one, according to Besnard and his colleagues. The receptor, a protein called CD36, is already known to exist in many tissues and is involved in fat storage, among other jobs; it is also goes by the name of fatty acid transporter, or FAT.

Rats and mice, not to mention many humans, have a natural preference for fatty food, and rats have already been shown to have CD36 proteins in their taste buds.

To see whether CD36 might be the tongue's fat detector, Besnard and his colleagues studied rats and mice that were either normal or had the gene for CD36 "knocked out," inactivating the protein.

They found that while the genetically normal animals naturally opted for fattier fare when given the choice, the CD36-deficient mice had no such preference. And when the researchers put fatty acids on the tongues of the normal animals, this alone triggered a release of fat-processing substances from the digestive organs. Again, the same was not true of mice lacking CD36 activity.

Though the body's regulation of fat intake is complex, these findings point to the importance of CD36 receptors on the tongue, Besnard told Reuters Health.

It's possible, he speculated, that the receptor's effects -- encouraging a preference for fat and launching a quick release of digestive substances -- conferred an evolutionary advantage when food was scarce. In modern times of plenty, however, this may be a disadvantage for the waistline.

Some past studies, Besnard and his colleagues note, have shown that obese people have a greater preference for fatty food than leaner individuals do -- which, they say, suggests that dysregulation in fat "perception" may play some role in obesity.

Research over the years has already shown that individuals vary widely in their ability to perceive different flavors, and inherited differences in taste receptors are thought to be involved. Experts estimate that while half of Americans are "medium" tasters, the rest are divided equally into "nontasters," who barely perceive one or more flavors, and "supertasters," who find some flavors too intense.

It's not clear yet how this all factors into eating habits and body weight. But it's "not unreasonable" to suggest that individual differences in CD36 play a role in fat perception, and possibly weight control, according to Nada A. Abumrad of Washington University School of Medicine in St. Louis.

"As more is learned about the specificity and mechanism of this receptor's function," Abumrad writes in a commentary, "it may be possible to devise strategies to treat some forms of obesity."

SOURCE: Journal of Clinical Investigation, November 2005.


Copyright 2005 Reuters News Service. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Copyright © 2005 ABC News Internet Ventures

http://abcnews.go.com/Health/print?id=1271417

[kyrasdad]

I noticed all the examples of "fatty" foods were generally high carb foods as well -- cheesecake, french fries and butter cookies. I think it's very plausible that that the tongue could harbor receptors for fatty acids. That's the body telling you to eat what it needs, I would think.

Wonder if they tried to isolate sugars or carbs, as opposed to just focusing blindly on the fat?

[Dodger]

The food list was put in by the reporter, not the researchers.

[Hybrid]

The "comfort foods" of rats are generally things like macaroni and cheese... things high in starch and fat. These are usually the comfort foods of people under stress as well.

[ItsTheWooo]

The "comfort foods" of rats are generally things like macaroni and cheese... things high in starch and fat. These are usually the comfort foods of people under stress as well.

Yep.
I am not surprised we have taste receptors for fat - it is ane ssential nutrient and an excellent source of energy.

Comfort foods are high in both sugar and fats - raw energy. They work synnergistically to produce that "feel good" effect. Sugar raises serotonin whichmakes you feel relaxed and calm. Fat indulges the senses providing a pleasing feeling of fullness to the meal, texture, and flavor.

Lots of people say "oh I over eat carbs" but what they really mean is "I over eat foods that are comforting which are high in carbs and fat". I don't know many people who go crazy for plain pasta or pixie sticks... but I know lots of people who like cookies and bread with sweet butter.

[Hybrid]

The trick is learning to be satisfied with high-fat/low-carb comfort foods. It doesn't produce the "feel good" of serotonin, but fat does trigger the release of cholecystokinin from the intestines, which has the effect of saying "I'm full," and then some.

I posted my ideas of how cholecystokinin is the key player in why fatty foods control addictions here (http://forum.lowcarber.org/showpost.php?p=5646655&postcount=24)

[Lessara]

Speaking of comfort foods, for me as a low carber, spinach, Cauliflower, or even onions/mushrooms with lots of butter is my comfort food. Strangly so is my red tea. Cheese is also but I have to watch my intolerance symptoms. :)

[ceberezin]

It's just amazing that the automatic assumption of these writers is to assume that a preference for fat is harmful. It wouldn't occur to them that a fat sensor on the tongue could be an adaptation to help us identify beneficial nutrients. The researcher believes that the fat sensor "conferred an evolutionary advantage when food was scarce." No, it's to help us identify preferred nutrients. Such is the tyrrany of the lipid hypothesis!

[Hybrid]

Interesting point, ceberezin. In the video "Walking with Cave Men," the Homo Habilis band is actually starving when they come across a lion's kill and proceed to break open the bones and eat the fat rich marrow inside. Habilis also had a taste for brains, but that isn't mentioned. Our ancestors had the advantage of rocks, which allowed access to dense nutrients other animals simply couldn't get to.

Still, the assumption is that our ancestors did not just eat brains and marrow when food was scarce. While eating a diet high in fat didn't trigger an evolutionary trend towards larger and larger brains, it did allow such a trend. I believe that the fat sensor confers an evolutionary advantage to creatures with brains bigger then those of chimpanzees.

Chimpanzees have big brains, but not as big as that of we humans. I hope the lack of ability to enjoy fat confers a corresponding disadvantage to nutritionists. I know it effects brain development negatively.

[Wyvrn]

Lightly steamed shrimp in a spicy coconut curry sauce (without added sugar) is my current favorite comfort food.

Wyv

[Hybrid]

Mine's chilli.

[foxgluvs]

Mine is chicken cooked in a creamy creme fraishe sauce...so I guess that's the fat that's making me crave it. I know that even down to the sensory things, fat has always been a more comforting food for me. Especially animal fats, I use to love the fat on beef/lamb/pork....anything really.

[Galliard]

I don't know many people who go crazy for plain pasta or pixie sticks...

Not to discount what you're saying, but yeah, my kids do go crazy for plain pasta and pixie sticks -- but then I didn't raise them right -- they were born during my low-fat, high-carb phase. I even try to get them to put butter on their pasta, but they want it plain.

[Nancy LC]

If we couldn't "taste" fat then would NF cottage cheese and 4% cottage cheese taste about the same? To me, there's a LOT of difference.