Live and Burn: Why Wasabi Bites
It should be called the Japanese ice-cream headache: The grated root of the wasabi plant, when taken in too high a dose, shoots straight to your nose triggering a few seconds of agony, then the sensation disappears as quickly as it came. So it’s fitting that the Japanese nickname for wasabi is namida or “tears.” This agony is different, of course, than the persistent mouth burn of chiles, which you often can’t escape no matter how much milk, bread, beer, or coffee you cram in there. To find out what accounts for the difference between these pesky sensations, I called Bruce Bryant, staff scientist at Monell Chemical Senses Center (www.monell.org), in Philadelphia. Bryant studies what’s going on in our nerves when food causes us pain.
The reason, Bryant says, that we feel wasabi’s excruciating effects in our noses and not our mouths is that the irritating compounds in wasabi (isothiocyanates) are volatile. This means that they evaporate — they leave the food on which they rode into your mouth and travel up into your nose, where they activate pain receptors. Bryant thinks that the isothiocyanates may then react with other compounds in the nose and change structure into something that doesn’t sting, hence the pain’s speedy departure.
The irritant in chiles (capsaicin), on the other hand, is not volatile, so it goes where the food goes, bugging the heck out of the membranes in your mouth and throat (and your eyes too, if, like me, you mindlessly rub them after eating buffalo wings). And since capsaicin dissolves readily in oil and the cell membranes in your mouth tissue are oily, the pain sticks around.
Yet despite his knowledge of the underlying neural processes involved in sensing pain, Bryant can’t help but recount his reaction to having too much wasabi in terms one usually reserves for describing medieval torture. When the hurting hits, he says, “conversation stops, because you have to attend to this spike in your head.”
We know of no way to cure the burn wasabi causes other than making sure not to eat too much — as for chilis, try a nice cold beer (just not too cold, or you’ll get the dreaded pain of a brain freeze).