Huffpost Science
The human tongue may have a sixth sense—and no, it doesn’t have anything to do with seeing ghosts. Researchers have found that in addition to recognizing sweet, sour, salty, savory, and bitter tastes, our tongues can also pick up on carbohydrates, the nutrients that break down into sugar and form our main source of energy.
Past studies have shown that some rodents can distinguish between sugars of different energy densities, while others can still tell carbohydrate and protein solutions apart even when their ability to taste sweetness is lost. A similar ability has been proposed in humans, with research showing that merely having carbohydrates in your mouth can improve physical performance.