WEDNESDAY, Nov. 2, 2005 (HealthDay News) -- No wonder fattening foods are so yummy: New research suggests the tongue may have taste sensors dedicated to detecting fat, just as it does for salty, sour, bitter and sweet foods.
The theory hasn't yet been confirmed in humans -- only mice have been tested -- and it's not clear what could be done with this new information.
But French researchers say the existence of a built-in 'fat sensor' might prove a boon for dieters if researchers then figure out a way of turning it off to make fatty foods less tempting.
"If we manage to taste less, maybe we'd eat and crave less," said Nada A. Abumrad, a professor of medicine at Washington University in St. Louis and the author of a commentary on the findings.
The new study, led by Phillippe Besnard of the Physiologie de la Nutrition ENSBANA, in Dijon, France, appear in the Nov. 1 issue of the Journal of Clinical Investigation.
Scientists used to think human taste buds only picked up on four types of flavor -- sweet, bitter, salty and sour. These were combined to help the brain figure out which foods might be dangerous and shouldn't be eaten.
In recent years, however, a new flavor got added to the list. It's "umami," best known as the taste of the Asian food additive MSG, the salt form of an amino acid. Umami is also found in some processed Western foods.
But what about fat? Clearly, people like it. But scientists have been divided on exactly why it tastes so good.
For a while, according to Abumrad, it was thought that humans like fat because it makes the digestive system think it's full. Then other scientists speculated that a preference for fat comes during the eating process because it has an appealing "mouth feel."
In the new study, the French researchers considered a variety of data and concluded they all pointed to the existence of a protein-based fat sensor. In fact, when a specific gene was turned off, mice stopped craving fat and their gastrointestinal systems ceased preparing for its arrival.
So, could it be possible to adjust the fat sensor to stop cravings for potato chips or ice cream? Yes, according to Abumrad. But he cautioned that fat only partially explains why so many individuals end up so obese.
"We're talking about one protein, and there are so many of them that play a role, and so many genes," she said.
Still, the fat sensor could be useful. "The obese person shouldn't think this is going to be the cure or the key (for obesity)," Abumrad said. "But there may be some way to manipulate it to modify how we taste."
For more on the science of taste, head to Kidshealth.org .