Unlocking the Science of Wasabi

toggle caption Rick Gayle Studio/CORBIS

Scientists have figured out why eating a dollop of wasabi makes it feel like your head might explode -- a particular class of receptor molecules on the surface of nerve cells. The discovery could lead to a new class of painkillers for a variety of conditions.

Wasabi is that sinus-stinging green paste that's served with sushi and sashimi. Lately, real wasabi -- Eutrema japonica, a root-like rhizome -- has become rare. Some restaurants use a mixture of horseradish and green food coloring, with little or no actual wasabi in the mix. But as it turns out, the kick is the same.

Some food scientists believe people eat hot foods to show off, or because they get an endorphin rush from the pain -- or they like the pain itself. Precisely why is still a matter for further inquiry.