How our taste buds know that sugar is sweet
Washington: A new research has attempted to find out how taste cells detect sugars.
The study by Monell Center and collaborators could lead to development of strategies to limit over-consumption.
"Detecting the sweetness of nutritive sugars is one of the most important tasks of our taste cells. Many of us eat too much sugar and to help limit overconsumption, we need to better understand how a sweet taste cell ``knows`` something is sweet,” said Robert F. Margolskee.
Scientists have known for some time that the T1r2+T1r3 receptors help us detect many sweet compounds, including sugars such as glucose and sucrose as well as artificial sweeteners, including saccharin and aspartame.
The results of the study showed that several sugar sensors from intestine and pancreas also are present in exactly those same sweet-sensing taste cells that have the T1r2+T1r3 sweet receptor.
"The taste system continues to amaze me at how smart it is and how it serves to integrate taste sensation with digestive processes," said Margolskee.
An intestinal glucose sensor also found to be located in the sweet-sensitive taste cells may provide an explanation for another mystery of sweet taste: why just a pinch of table salt tastes sweet or salt added to baked goods enhances sweet taste.
The SGLT1 sensor is a transporter that moves glucose into the sweet taste cell when sodium is present, thus triggering the cell to register sweetness.
In pancreas, the sugar sensor known as the KATP channel, monitors glucose levels and triggers insulin release when they rise. The authors speculate that KATP may function in sweet taste cells to modulate taste cell sensitivity to sugars according to metabolic needs.
"Sweet taste cells have turned out to be quite complex. The presence of the KATP channel suggests that taste cells may play a role in regulating our sensitivity to sweet taste under different nutritional conditions," said Karen K. Yee.
"This knowledge may someday help us understand how to limit overconsumption of sweet foods."
The team now plans to understand the complex connections between taste cells and the digestive and endocrine systems.
The study is published in the Proceedings of the National Academy of Sciences USA.