Word has it that the spicy green dollop of wasabi accompanying your sushi might not be wasabi at all. Restaurants and grocery stores have been known to substitute the grated Japanese root with a combination of horseradish, mustard, cornstarch, and food coloring. While this mixture is cost effective — growing real wasabi is an expensive, weather-sensitive, multiple-year endeavor — it denies diners of the real herb's flavor and health benefits. True wasabi has a tangy spiciness that authentically complements Japanese flavors, while keeping food clean and nutritious. Wasabi's antimicrobial properties help foods like sashimi and sushi stay free of bacteria. Plus, its isothiocyanates — natural chemical compounds — help prevent cancer, blood clots, and asthmatic reactions. So when you scan the shelf for wasabi powder, paste, or even wasabi-flavored chips and peas, look for ingredient lists that include 100 percent real wasabi with no added horseradish or mustard.