So far, it was believed that the human tongue is capable of perceiving only 5 tastes, namely saltiness, sweetness, sourness, savouriness and bitterness. But, scientists have now found that the tongue has the capacity to recognize yet another taste, that is, the taste of carbohydrates.
Carbohydrates are molecules that contain carbon, hydrogen and oxygen. They are key nutrients that form the main source of energy for the body. Carbohydrates break down into sugar, and this sugar is used by the body to energize cells, tissues and organs.
The findings of the new study may explain both why diet products are not as pleasurable as their real counterparts and why athletes get instantly pepped up by consuming carbohydrate-loaded drinks - even before the conversion of carbs into energy takes place in their bodies.
Sport drinks are packed with sugary carbohydrates that give enormous energy, and tongues are found to have a special taste for them.
In a clinical trial, participants were asked to squeeze a sensor that was held between their right index fingers and thumbs when a visual cue was shown.
Simultaneously, the participants were made to rinse their mouths with two artificially sweetened fluids of which only one contained carbohydrates. The participants' brains were able to distinguish between the two, though both seemed to have a similar taste.
The trial also revealed that there was a 30 percent spike in brain activity after carb fluid consumption, especially in those portions of the brain that regulate movement and vision.
The increased activity of the brain was supposed to be due to the tongue signaling the brain beforehand that the carb energy was about to arrive.
"Carbohydrates are extremely powerful stimuli that have profound and immediate effects on the brain and the systems it controls," explained Dr. Nicholas Gant, whose team undertook the research at the University of Auckland's Centre for Brain Research.
When the brains are fed in the form of artificial sweeteners and diet foods and deprived of carbs, they are quick to grasp that they are being fooled.
"It's becoming evident that the brain knows far more about the foods we ingest that just our perception of taste," said Gant.
The new study is set to be published in the journal Appetite.