Guess we don't know much about our taste buds after all.
Sweet, sour, salty, bitter--the first four tastes humans have ever known. And then in 1908, a new one called umami was "discovered". This fifth taste even had to fight its way to be scientifically recognized (mami means“delicious” or “yummy” in Japanese) and be “official” in 2002.
Now, there might just be a new candidate that will, again, change our science books. Recent research from scientists at the University of UC Santa Barbara (UCSB) and Korea, appears to discover a sixth to add to the list – calcium.
They claimed that being able to sense calcium is essential as partaking too much or too little can be dangerous to our body. So, to test this, they utilized vinegar flies as these can taste calcium as well. And just like us, they need a certain amount of the stuff in order to survive. They found that the flies actually refuse to take those foods high in calcium but willingly consumes those that have low levels.
“It turns out that fruit flies don’t have a mechanism for sensing low calcium even though it’s good for them, but they are trying to guard against consuming too much calcium,” senior author Craig Montell, from UCSB’s Molecular, Cellular, and Developmental Biology and Neuroscience department, said in a statement.
Three taste neurons called gustatory receptor neurons (GRNs) are found to enable the sensing of calcium. So, they tried to remove one from the flies. This resulted to them, consuming too much calcium as they weren't able to distinguish it, consequently leading to health problems, and, ultimately, died.
“Surprisingly, we found that calcium avoidance occurred through two mechanisms: activation of a unique class of GRNs, distinct from those that sense bitter compounds and which cause a stop-feeding signal when activated. In addition, calcium inhibits sugar-activated GRNs,” explained Montell.
“In humans, high calcium is associated with many diseases and can even be life threatening. Our results suggest that calcium taste might function primarily as a deterrent in wide range of animals, including humans,” he added.
For those who are curious, calcium actually taste like something both slightly bitter and sour at the same time. Think about milk (or anything else dairy), kale, and sardines and you'll get the picture!
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