Tanycytes – cells found in part of the brain that controls energy levels – detect nutrients in food and tell the brain directly about the food we have eaten, according to new research from the University of Warwick.
According to the new research, tanycytes in the brain respond to amino acids found in foods, via the same receptors that sense the flavor of amino acids (“umami” taste), which are found in the taste buds of the tongue. The finding could lead to new approaches to dieting and treatment for obesity.
Two amino acids that react most with tanycytes – and therefore are likely to make you feel fuller – are arginine and lysine.
These amino acids are found in high concentration in foods such as
- pork shoulder
- beef sirloin steak
So eating those foods will activate the tanycytes and make you feel less hungry quicker.
Tanycytes And Amino Acids
The researchers, led by Professor Nicholas Dale in the School of Life Sciences, made their discovery by adding concentrated amounts of arginine and lysine into brain cells, which were made fluorescent so that any microscopic reactions would be visible. They observed that within thirty seconds, the tanycytes detected and responded to the amino acids, releasing information to the part of the brain that controls appetite and body weight.
They found that signals from amino acids are directly detected by the umami taste receptors by removing or blocking these receptors and observing that the amino acids no longer reacted with tanycytes.
Dale, who is Ted Pridgeon Professor of Neuroscience at the University of Warwick, commented:
“Amino acid levels in blood and brain following a meal are a very important signal that imparts the sensation of feeling full. Finding that tanycytes, located at the centre of the brain region that controls body weight, directly sense amino acids has very significant implications for coming up with new ways to help people to control their body weight within healthy bounds.”
This discovery opens up new possibilities for creating more effective diets – and even future treatments to suppress one’s appetite by directly activating the brain’s tanycytes, bypassing food and the digestive system.
Nearly two thirds of the UK population is overweight or obese. This excess weight elevates the risk of premature death and a range of illnesses, such as cancer, diabetes, cardiovascular disease and stroke, which greatly reduce quality of life.
In conclusion, the authors write,
“Two receptors previously implicated in taste cells, the Tas1r1/Tas1r3 heterodimer and mGluR4, contribute to the detection of a range of amino acids by tanycytes in CSF.”
A new understanding of how appetite functions could curb the growing obesity crisis.
Greta Lazutkaite, Alice Soldà, Kristina Lossow, Wolfgang Meyerhof, Nicholas Dale
Amino acid sensing in hypothalamic tanycytes via umami taste receptors
Molecular Metabolism https://doi.org/10.1016/j.molmet.2017.08.015
Image: Professor Nicholas Dale/Greta Lazutkaite