Does wasabi contain any healthful properties?
-- Peter Aitken
(city withheld), MA
Depends on which wasabi you are referring to.
Traditional wasabi (pictured at right) is obtained from the wasabia japonica plant.
Its underground stem is grated moments before consumption, since exposure to air significantly decreases its powerful taste.
This form of wasabi -- commonly referred to as "wasabi root" -- is a good source of potassium, calcium, vitamin C, betacarotene, and quite a bit of phytonutrients and antioxidants.
Wasabi root is also a source of isothiocyanates -- compounds found in relatively high quantities in raw broccoli and raw cabbage that have been linked with tumor inhibition.
However, the wasabi served alongside sushi at practically every Japanese restaurant in the United States is the end result of mixing water and a dry powder made up of horseradish, dry mustard, and some food coloring.
There is nothing inherently unhealthy about this knockoff, but it also lacks the nutrition of the real deal.
Faux wasabi is higher in sodium, though. Two teaspoons of the mean green machine add 200 milligrams of the mineral to your meal. That same amount of real wasabi would only add up to 2 milligrams.